Receptor Interactive Protein Kinase 3 Promotes Cisplatin-Triggered Necrosis in Apoptosis-Resistant Esophageal Squamous Cell Carcinoma Cells

PubMed Central

Zhao, Nan; Zhou, Lanping; Liu, Fang; Cichacz, Zbigniew; Zhang, Lin; Zhan, Qimin; Zhao, Xiaohang

2014-01-01

Cisplatin-based chemotherapy is currently the standard treatment for locally advanced esophageal cancer. Cisplatin has been shown to induce both apoptosis and necrosis in cancer cells, but the mechanism by which programmed necrosis is induced remains unknown. In this study, we provide evidence that cisplatin induces necrotic cell death in apoptosis-resistant esophageal cancer cells. This cell death is dependent on RIPK3 and on necrosome formation via autocrine production of TNFα. More importantly, we demonstrate that RIPK3 is necessary for cisplatin-induced killing of esophageal cancer cells because inhibition of RIPK1 activity by necrostatin or knockdown of RIPK3 significantly attenuates necrosis and leads to cisplatin resistance. Moreover, microarray analysis confirmed an anti-apoptotic molecular expression pattern in esophageal cancer cells in response to cisplatin. Taken together, our data indicate that RIPK3 and autocrine production of TNFα contribute to cisplatin sensitivity by initiating necrosis when the apoptotic pathway is suppressed or absent in esophageal cancer cells. These data provide new insight into the molecular mechanisms underlying cisplatin-induced necrosis and suggest that RIPK3 is a potential marker for predicting cisplatin sensitivity in apoptosis-resistant and advanced esophageal cancer. PMID:24959694

Autocrine Positive Feedback Regulation of Prolactin Release From Tilapia Prolactin Cells and Its Modulation by Extracellular Osmolality.

PubMed

Yamaguchi, Yoko; Moriyama, Shunsuke; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

2016-09-01

Prolactin (PRL) is a vertebrate hormone with diverse actions in osmoregulation, metabolism, reproduction, and in growth and development. Osmoregulation is fundamental to maintaining the functional structure of the macromolecules that conduct the business of life. In teleost fish, PRL plays a critical role in osmoregulation in fresh water. Appropriately, PRL cells of the tilapia are directly osmosensitive, with PRL secretion increasing as extracellular osmolality falls. Using a model system that employs dispersed PRL cells from the euryhaline teleost fish, Oreochromis mossambicus, we investigated the autocrine regulation of PRL cell function. Unknown was whether these PRL cells might also be sensitive to autocrine feedback and whether possible autocrine regulation might interact with the well-established regulation by physiologically relevant changes in extracellular osmolality. In the cell-perfusion system, ovine PRL and two isoforms of tilapia PRL (tPRL), tPRL177 and tPRL188, stimulated the release of tPRLs from the dispersed PRL cells. These effects were significant within 5-10 minutes and lasted the entire course of exposure, ceasing within 5-10 minutes of removal of tested PRLs from the perifusion medium. The magnitude of response varied between tPRL177 and tPRL188 and was modulated by extracellular osmolality. On the other hand, the gene expression of tPRLs was mainly unchanged or suppressed by static incubations of PRL cells with added PRLs. By demonstrating the regulatory complexity driven by positive autocrine feedback and its interaction with osmotic stimuli, these findings expand upon the knowledge that pituitary PRL cells are regulated complexly through multiple factors and interactions.

Dominant-negative mutants of platelet-derived growth factor revert the transformed phenotype of human astrocytoma cells.

PubMed Central

Shamah, S M; Stiles, C D; Guha, A

1993-01-01

Malignant astrocytoma is the most common primary human brain tumor. Most astrocytomas express a combination of platelet-derived growth factor (PDGF) and PDGF receptor which could close an autocrine loop. It is not known whether these autocrine loops contribute to the transformed phenotype of astrocytoma cells or are incidental to that phenotype. Here we show that dominant-negative mutants of the PDGF ligand break the autocrine loop and revert the phenotype of BALB/c 3T3 cells transformed by the PDGF-A or PDGF-B (c-sis) gene. Then, we show that these mutants are selective in that they do not alter the phenotype of 3T3 cells transformed by an activated Ha-ras or v-src gene or by simian virus 40. Finally, we show that these mutants revert the transformed phenotype of two independent human astrocytoma cell lines. They have no effect on the growth of human medulloblastoma, bladder carcinoma, or colon carcinoma cell lines. These observations are consistent with the view that PDGF autocrine loops contribute to the transformed phenotype of at least some human astrocytomas. Images PMID:8246942

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dewitt, Ann E.; Dong, Jian Y.; Wiley, H S.

Autocrine signaling is important in normal tissue physiology as well as pathological conditions. It is difficult to analyze these systems, however, because they are both self-contained and recursive. To understand how parameters, such as ligand production and receptor expression influence autocrine activity, we investigated a human epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) loop engineered into mouse B82 fibroblasts. We varied the level of ligand production using the tet-off expression system and used metalloprotease inhibitors to modulate ligand release. Receptor expression was varied using antagonistic, blocking antibodies. We compared autocrine ligand release to receptor activation using a microphysiometer-based assay andmore » analyzed our data with a quantitative model of ligand release and receptor dynamics. We found that the activity of our autocrine system could be described in terms of a simple ratio between the rate of ligand production (VL) and the rate of receptor production (VR). At a VL/VR ratio of < 0.3, essentially no ligand was found in the extracellular medium, but a significant number cell receptors (30-40%) were occupied. As the VL/VR ratio increased from 0.3 towards unity, receptor occupancy increased, and significant amounts of ligand now appeared in the medium. Above a VL/VR ratio of 1.0, receptor occupancy approached saturation and most of the released ligand was lost into the medium. Analysis of human mammary epithelial cells showed that a VL/VR ratio of < 5 x 10 -4 was sufficient to evoke >20% of a maximal proliferative response. This suggests that natural autocrine systems are active even when no ligand appears in the extracellular medium; i.e., they operate 'invisibly' to general detection.« less

Autocrine VEGF signaling promotes cell proliferation through a PLC-dependent pathway and modulates Apatinib treatment efficacy in gastric cancer.

PubMed

Lin, Yi; Zhai, Ertao; Liao, Bing; Xu, Lixia; Zhang, Xinhua; Peng, Sui; He, Yulong; Cai, Shirong; Zeng, Zhirong; Chen, Minhu

2017-02-14

Tumor cells produce vascular endothelial growth factor (VEGF) which interact with the membrane or cytoplasmic VEGF receptors (VEGFRs) to promote cell growth in an angiogenesis-independent fashion. Apatinib, a highly selective VEGFR2 inhibitor, is the only effective drug for patients with terminal gastric cancer (GC) who have no other chemotherapeutic options. However, its treatment efficacy is still controversy and the mechanism behind remains undetermined. In this study, we aimed to investigate the role of autocrine VEGF signaling in the growth of gastric cancer cells and the efficacy of Apatinib treatment. The expression of phosphor VEGFR2 in gastric cancer cell lines was determined by real-time PCR, immunofluorescence, and Western blot. The gastric cancer cells were administrated with or without recombination human VEGF (rhVEGF), VEGFR2 neutralizing antibody, U73122, SU1498, and Apatinib. The nude mice were used for xenograft tumor model. we found that autocrine VEGF induced high VEGFR2-expression, promoted phosphorylation of VEGFR2, and further enhanced internalization of pVEGFR2 in gastric cancer cells. The autocrine VEGF was self-sustained through increasing VEGF mRNA and protein expression. It exerted pro-proliferative effect through a PLC-ERK1/2 dependent pathway. Furthermore, we demonstrated that in VEGFR2 overexpressing gastric cancer cells, Apatinib inhibited cell proliferation in vitro and delayed xenograft tumor growth in vivo. However, these effects were not observed in VEGFR2 low expressing gastric cancer cells. These results suggested that autocrine VEGF signaling promotes gastric cancer cell proliferation and enhances Apatinib treatment outcome in VEGFR2 overexpression gastric cancer cells both in vitro and in vivo. This study would enable better stratification of gastric cancer patients for clinical treatment decision.

Autocrine VEGF signaling promotes cell proliferation through a PLC-dependent pathway and modulates Apatinib treatment efficacy in gastric cancer

PubMed Central

Xu, Lixia; Zhang, Xinhua; Peng, Sui; He, Yulong; Cai, Shirong; Zeng, Zhirong; Chen, Minhu

2017-01-01

Background Tumor cells produce vascular endothelial growth factor (VEGF) which interact with the membrane or cytoplasmic VEGF receptors (VEGFRs) to promote cell growth in an angiogenesis-independent fashion. Apatinib, a highly selective VEGFR2 inhibitor, is the only effective drug for patients with terminal gastric cancer (GC) who have no other chemotherapeutic options. However, its treatment efficacy is still controversy and the mechanism behind remains undetermined. In this study, we aimed to investigate the role of autocrine VEGF signaling in the growth of gastric cancer cells and the efficacy of Apatinib treatment. Methods The expression of phosphor VEGFR2 in gastric cancer cell lines was determined by real-time PCR, immunofluorescence, and Western blot. The gastric cancer cells were administrated with or without recombination human VEGF (rhVEGF), VEGFR2 neutralizing antibody, U73122, SU1498, and Apatinib. The nude mice were used for xenograft tumor model. Results we found that autocrine VEGF induced high VEGFR2-expression, promoted phosphorylation of VEGFR2, and further enhanced internalization of pVEGFR2 in gastric cancer cells. The autocrine VEGF was self-sustained through increasing VEGF mRNA and protein expression. It exerted pro-proliferative effect through a PLC-ERK1/2 dependent pathway. Furthermore, we demonstrated that in VEGFR2 overexpressing gastric cancer cells, Apatinib inhibited cell proliferation in vitro and delayed xenograft tumor growth in vivo. However, these effects were not observed in VEGFR2 low expressing gastric cancer cells. Conclusion These results suggested that autocrine VEGF signaling promotes gastric cancer cell proliferation and enhances Apatinib treatment outcome in VEGFR2 overexpression gastric cancer cells both in vitro and in vivo. This study would enable better stratification of gastric cancer patients for clinical treatment decision. PMID:28061477

Evidence for autocrine and paracrine regulation of allergen-induced mast cell mediator release in the guinea pig airways.

PubMed

Yu, Li; Liu, Qi; Canning, Brendan J

2018-03-05

Mast cells play an essential role in immediate type hypersensitivity reactions and in chronic allergic diseases of the airways, including asthma. Mast cell mediator release can be modulated by locally released autacoids and circulating hormones, but surprisingly little is known about the autocrine effects of mediators released upon mast cell activation. We thus set out to characterize the autocrine and paracrine effects of mast cell mediators on mast cell activation in the guinea pig airways. By direct measures of histamine, cysteinyl-leukotriene and thromboxane release and with studies of allergen-evoked contractions of airway smooth muscle, we describe a complex interplay amongst these autacoids. Notably, we observed an autocrine effect of the cysteinyl-leukotrienes acting through cysLT 1 receptors on mast cell leukotriene release. We confirmed the results of previous studies demonstrating a marked enhancement of mast cell mediator release following cyclooxygenase inhibition, but we have extended these results by showing that COX-2 derived eicosanoids inhibit cysteinyl-leukotriene release and yet are without effect on histamine release. Given the prominent role of COX-1 inhibition in aspirin-sensitive asthma, these data implicate preformed mediators stored in granules as the initial drivers of these adverse reactions. Finally, we describe the paracrine signaling cascade leading to thromboxane synthesis in the guinea pig airways following allergen challenge, which occurs indirectly, secondary to cysLT 1 receptor activation on structural cells and/ or leukocytes within the airway wall, and a COX-2 dependent synthesis of the eicosanoid. The results highlight the importance of cell-cell and autocrine interactions in regulating allergic responses in the airways. Copyright © 2017. Published by Elsevier B.V.

[Enhancement of wound healing by taspine and its effect on fibroblast].

PubMed

Dong, Yalin; He, Langchong; Chen, Fang

2005-07-01

To study the effect of taspine on enhancement of skin wound healing and its effect on fibroblast proliferation and autocrine. The plerosis effect of taspine on experimental skin wound was observed in vivo. Different concentrations of taspine were added in vitro and MTT technique was applied to observe its effect on fibroblast proliferation, the levels of transforming growth factor-beta1 (TGF-13P) and epidermal growth factor (EGF) were determined by ELISA. In vivo, exo-applied taspine 300 microg and 150 microg accelerated the recovery of skin wound. In vitro, 0.50-0.4 microg/ml taspine could increase autocrine of TGF-beta1and EGF by fibroblast, but it showed no effect on L929 fibroblast proliferation. Taspine enhances wound healing by increasing the autocrine of TGF-beta1 and EGF by fibroblast.

Osteoclast Inhibitory Peptide-1 Therapy for Paget’s Disease

DTIC Science & Technology

2010-08-01

Carolina 29425 Osteoclast inhibitory peptide-1 (OIP) is an autocrine/paracrine inhibitor of osteoclast differentia- tion, and mice that overexpress OIP-1...have previously identified and characterized theosteoclast inhibitory peptide-1 (OIP-1/hSca) as an autocrine/paracrine inhibitor of osteoclast...H, Takai T, Kodama T, Morio T, Geha RS, Kitamura D, Kurosaki T, Ellmeier W, Takayanagi H 2008 Tyrosine kinases Btk and Tec reg- ulate osteoclast

The Functional Effect of an Amphiregulin Autocrine Loop on Inflammatory Breast Cancer Progression

DTIC Science & Technology

2007-03-01

autocrine loop exists in pancreatic cancer, colon cancer, and hepatocellular carcinoma (27-29). AR expression was also found to be strongly correlated...J, Erroba, E, Perugorria, MJ, et al. Amphiregulin contributes to the transformed phenotype of human hepatocellular carcinoma cells. Cancer Res... hepatocellular carcinoma (27–29). AR expression was also found to be * This research was supported by National Institutes of Health Grants R01

Minireview: Progesterone Regulation of Proliferation in the Normal Human Breast and in Breast Cancer: A Tale of Two Scenarios?

PubMed Central

Graham, J. Dinny; Clarke, Christine L.

2015-01-01

Progesterone (P), which signals through the P receptor (PR), is critical in normal development of the breast, but its signaling axis is also a major driver of breast cancer risk. Here we review recent advances in the understanding of P signaling in the normal human breast, with a focus on the importance of the balance between autocrine and paracrine signaling. To date, most data (which derive largely from mouse models or human breast cancer cell line studies) have demonstrated that the vast majority of PR+ cells appear to act as “sensor” cells, which respond to P stimulation by translating these hormonal cues into paracrine signals. However, growing evidence suggests that, dependent on the cellular context, P may also signal in an autocrine manner in a subset of cells in the normal mouse mammary gland and human breast. It has been suggested that it may be dysregulation of this autocrine signaling, resulting in a “switch” from a predominance of paracrine signaling to autocrine signaling in PR+ cells, which is an early event during breast tumorigenesis. This review summarizes current evidence in the literature that demonstrates the mechanisms through which P acts in the normal human breast, as well as highlighting the important questions that remain unanswered. PMID:26266959

Apatinib inhibits VEGF signaling and promotes apoptosis in intrahepatic cholangiocarcinoma.

PubMed

Peng, Hong; Zhang, Qiuyang; Li, Jiali; Zhang, Ning; Hua, Yunpeng; Xu, Lixia; Deng, Yubin; Lai, Jiaming; Peng, Zhenwei; Peng, Baogang; Chen, Minhu; Peng, Sui; Kuang, Ming

2016-03-29

Tumor cells co-express vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) that interact each other to support a self-sustainable cell growth. So far, this autocrine VEGF loop is not reported in human intrahepatic cholangiocarcinoma (ICC). Apatinib is a highly selective VEGFR2 inhibitor, but its effects on ICC have not been investigated. In this study, we reported that VEGF and phosphorylated VEGFR2 were expressed at a significantly high level in ICC patient tissues (P<0.05). In vitro, treating ICC cell lines RBE and SSP25 with recombinant human VEGF (rhVEGF) induced phosphorylation of VEGFR1 (pVEGFR1) and VEGFR2 (pVEGFR2); however, only the VEGFR2 played a role in the anti-apoptotic cell growth through activating a PI3K-AKT-mTOR anti-apoptotic signaling pathway which generated more VEGF to enter this autocrine loop. Apatinib inhibited the anti-apoptosis induced by VEGF signaling, and promoted cell death in vitro. In addition, Apatinib treatment delayed xenograft tumor growth in vivo. In conclusion, the autocrine VEGF/VEGFR2 signaling promotes ICC cell survival. Apatinib inhibits anti-apoptotic cell growth through suppressing the autocrine VEGF signaling, supporting a potential role for using Apatinib in the treatment of ICC.

Apatinib inhibits VEGF signaling and promotes apoptosis in intrahepatic cholangiocarcinoma

PubMed Central

Zhang, Ning; Hua, Yunpeng; Xu, Lixia; Deng, Yubin; Lai, Jiaming; Peng, Zhenwei; Peng, Baogang; Chen, Minhu; Peng, Sui; Kuang, Ming

2016-01-01

Tumor cells co-express vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) that interact each other to support a self-sustainable cell growth. So far, this autocrine VEGF loop is not reported in human intrahepatic cholangiocarcinoma (ICC). Apatinib is a highly selective VEGFR2 inhibitor, but its effects on ICC have not been investigated. In this study, we reported that VEGF and phosphorylated VEGFR2 were expressed at a significantly high level in ICC patient tissues (P<0.05). In vitro, treating ICC cell lines RBE and SSP25 with recombinant human VEGF (rhVEGF) induced phosphorylation of VEGFR1 (pVEGFR1) and VEGFR2 (pVEGFR2); however, only the VEGFR2 played a role in the anti-apoptotic cell growth through activating a PI3K-AKT-mTOR anti-apoptotic signaling pathway which generated more VEGF to enter this autocrine loop. Apatinib inhibited the anti-apoptosis induced by VEGF signaling, and promoted cell death in vitro. In addition, Apatinib treatment delayed xenograft tumor growth in vivo. In conclusion, the autocrine VEGF/VEGFR2 signaling promotes ICC cell survival. Apatinib inhibits anti-apoptotic cell growth through suppressing the autocrine VEGF signaling, supporting a potential role for using Apatinib in the treatment of ICC. PMID:26967384

Endothelium-derived fibronectin regulates neonatal vascular morphogenesis in an autocrine fashion.

PubMed

Turner, Christopher J; Badu-Nkansah, Kwabena; Hynes, Richard O

2017-11-01

Fibronectin containing alternatively spliced EIIIA and EIIIB domains is largely absent from mature quiescent vessels in adults, but is highly expressed around blood vessels during developmental and pathological angiogenesis. The precise functions of fibronectin and its splice variants during developmental angiogenesis however remain unclear due to the presence of cardiac, somitic, mesodermal and neural defects in existing global fibronectin KO mouse models. Using a rare family of surviving EIIIA EIIIB double KO mice, as well as inducible endothelial-specific fibronectin-deficient mutant mice, we show that vascular development in the neonatal retina is regulated in an autocrine manner by endothelium-derived fibronectin, and requires both EIIIA and EIIIB domains and the RGD-binding α5 and αv integrins for its function. Exogenous sources of fibronectin do not fully substitute for the autocrine function of endothelial fibronectin, demonstrating that fibronectins from different sources contribute differentially to specific aspects of angiogenesis.

Autocrine and/or paracrine insulin-like growth factor-I activity in skeletal muscle

NASA Technical Reports Server (NTRS)

Adams, Gregory R.

2002-01-01

Similar to bone, skeletal muscle responds and adapts to changes in loading state via mechanisms that appear to be intrinsic to the muscle. One of the mechanisms modulating skeletal muscle adaptation it thought to involve the autocrine and/or paracrine production of insulinlike growth factor-I. This brief review outlines components of the insulinlike growth factor-I system as it relates to skeletal muscle and provides the rationale for the theory that insulinlike growth factor-I is involved with muscle adaptation.

PGE2 maintains self-renewal of human adult stem cells via EP2-mediated autocrine signaling and its production is regulated by cell-to-cell contact.

PubMed

Lee, Byung-Chul; Kim, Hyung-Sik; Shin, Tae-Hoon; Kang, Insung; Lee, Jin Young; Kim, Jae-Jun; Kang, Hyun Kyoung; Seo, Yoojin; Lee, Seunghee; Yu, Kyung-Rok; Choi, Soon Won; Kang, Kyung-Sun

2016-05-27

Mesenchymal stem cells (MSCs) possess unique immunomodulatory abilities. Many studies have elucidated the clinical efficacy and underlying mechanisms of MSCs in immune disorders. Although immunoregulatory factors, such as Prostaglandin E2 (PGE2), and their mechanisms of action on immune cells have been revealed, their effects on MSCs and regulation of their production by the culture environment are less clear. Therefore, we investigated the autocrine effect of PGE2 on human adult stem cells from cord blood or adipose tissue, and the regulation of its production by cell-to-cell contact, followed by the determination of its immunomodulatory properties. MSCs were treated with specific inhibitors to suppress PGE2 secretion, and proliferation was assessed. PGE2 exerted an autocrine regulatory function in MSCs by triggering E-Prostanoid (EP) 2 receptor. Inhibiting PGE2 production led to growth arrest, whereas addition of MSC-derived PGE2 restored proliferation. The level of PGE2 production from an equivalent number of MSCs was down-regulated via gap junctional intercellular communication. This cell contact-mediated decrease in PGE2 secretion down-regulated the suppressive effect of MSCs on immune cells. In conclusion, PGE2 produced by MSCs contributes to maintenance of self-renewal capacity through EP2 in an autocrine manner, and PGE2 secretion is down-regulated by cell-to-cell contact, attenuating its immunomodulatory potency.

Serotonergic Mechanisms Regulating the GI Tract: Experimental Evidence and Therapeutic Relevance

PubMed Central

Terry, Natalie

2017-01-01

Serotonin (5-hydroxytryptamine; 5-HT) is best known as a neurotransmitter critical for central nervous system (CNS) development and function. 95% of the body’s serotonin, however, is produced in the intestine where it has been increasingly recognized for its hormonal, autocrine, paracrine, and endocrine actions. This chapter provides the most current knowledge of the critical autocrine and paracrine roles of 5-HT in intestinal motility and inflammation as well as its function as a hormone in osteocyte homeostasis. Therapeutic applications in each of these areas are also discussed. PMID:28035530

Autocrine HBEGF expression promotes breast cancer intravasation, metastasis and macrophage-independent invasion in vivo

PubMed Central

Zhou, Zhen Ni; Sharma, Ved P.; Beaty, Brian T.; Roh-Johnson, Minna; Peterson, Esther A.; Van Rooijen, Nico; Kenny, Paraic A.; Wiley, H. Steven; Condeelis, John S.; Segall, Jeffrey E.

2013-01-01

Increased expression of HBEGF in ER negative breast tumors is correlated with enhanced metastasis to distant organ sites and more rapid disease recurrence upon removal of the primary tumor. Our previous work has demonstrated a paracrine loop between breast cancer cells and macrophages in which the tumor cells are capable of stimulating macrophages through the secretion of CSF-1 while the tumor associated macrophages (TAMs) in turn aid in tumor cell invasion by secreting EGF. To determine how the autocrine expression of EGFR ligands by carcinoma cells would affect this paracrine loop mechanism, and in particular whether tumor cell invasion depends on spatial ligand gradients generated by TAMs, we generated cell lines with increased HBEGF expression. We find that autocrine HBEGF expression enhanced in vivo intravasation and metastasis, and resulted in a novel phenomenon in which macrophages were no longer required for in vivo invasion of breast cancer cells. In vitro studies revealed that expression of HBEGF enhanced invadopodium formation, thus providing a mechanism for cell autonomous invasion. The increased invadopodium formation was directly dependent on EGFR signaling, as demonstrated by a rapid decrease in invadopodia upon inhibition of autocrine HBEGF/EGFR signaling as well as inhibition of signaling downstream of EGFR activation. HBEGF expression also resulted in enhanced invadopodium function via upregulation of MMP2 and MMP9 expression. We conclude that high levels of HBEGF expression can short-circuit the tumor cell/macrophage paracrine invasion loop, resulting in enhanced tumor invasion that is independent of macrophage signaling. PMID:24013225

Autocrine HBEGF expression promotes breast cancer intravasation, metastasis and macrophage-independent invasion in vivo.

PubMed

Zhou, Z N; Sharma, V P; Beaty, B T; Roh-Johnson, M; Peterson, E A; Van Rooijen, N; Kenny, P A; Wiley, H S; Condeelis, J S; Segall, J E

2014-07-17

Increased expression of HBEGF in estrogen receptor-negative breast tumors is correlated with enhanced metastasis to distant organ sites and more rapid disease recurrence upon removal of the primary tumor. Our previous work has demonstrated a paracrine loop between breast cancer cells and macrophages in which the tumor cells are capable of stimulating macrophages through the secretion of colony-stimulating factor-1 while the tumor-associated macrophages (TAMs), in turn, aid in tumor cell invasion by secreting epidermal growth factor. To determine how the autocrine expression of epidermal growth factor receptor (EGFR) ligands by carcinoma cells would affect this paracrine loop mechanism, and in particular whether tumor cell invasion depends on spatial ligand gradients generated by TAMs, we generated cell lines with increased HBEGF expression. We found that autocrine HBEGF expression enhanced in vivo intravasation and metastasis and resulted in a novel phenomenon in which macrophages were no longer required for in vivo invasion of breast cancer cells. In vitro studies revealed that expression of HBEGF enhanced invadopodium formation, thus providing a mechanism for cell autonomous invasion. The increased invadopodium formation was directly dependent on EGFR signaling, as demonstrated by a rapid decrease in invadopodia upon inhibition of autocrine HBEGF/EGFR signaling as well as inhibition of signaling downstream of EGFR activation. HBEGF expression also resulted in enhanced invadopodium function via upregulation of matrix metalloprotease 2 (MMP2) and MMP9 expression levels. We conclude that high levels of HBEGF expression can short-circuit the tumor cell/macrophage paracrine invasion loop, resulting in enhanced tumor invasion that is independent of macrophage signaling.

Acetylcholine released from T cells regulates intracellular Ca2+, IL-2 secretion and T cell proliferation through nicotinic acetylcholine receptor.

PubMed

Mashimo, Masato; Iwasaki, Yukari; Inoue, Shoko; Saito, Shoko; Kawashima, Koichiro; Fujii, Takeshi

2017-03-01

T lymphocytes synthesize acetylcholine (ACh) and express muscarinic and nicotinic ACh receptors (mAChR and nAChR, respectively) responsible for increases in the intracellular Ca 2+ concentration ([Ca 2+ ] i ). Our aim in the present study was to assess whether autocrine ACh released from T lymphocytes regulates their physiological functions. MOLT-3 human leukemic cell line and murine splenocytes were loaded with fura-2 to monitor [Ca 2+ ] i changes in the absence or presence of several AChR antagonists, including mecamylamine, methyllycaconitine and scopolamine. Real-time PCR and ELISA were performed to measure interleukin-2 (IL-2) mRNA and protein levels. T lymphocytes constitutively produce sufficient amounts of ACh to elicit autocrine changes in [Ca 2+ ] i . These autocrine ACh-evoked [Ca 2+ ] i transients were mediated by nAChRs and then influx of extracellular Ca 2+ . Mecamylamine, a nAChR inhibitor, suppressed not only these [Ca 2+ ] i transients, but also IL-2 release and T cell proliferation. Here, we confirmed that T lymphocytes utilize ACh as a tool to interact with each other and that autocrine ACh-activated nAChRs are involved in cytokine release and cell proliferation. These findings suggest the possibility that nAChR agonists and antagonists and smoking are able to modulate immune function, which in turn suggests the therapeutic potential of immune activation or suppression using nAChR agonists or antagonists. Copyright © 2016 Elsevier Inc. All rights reserved.

Formation of PI 3-kinase products in platelets by thrombin, but not collagen, is dependent on synergistic autocrine stimulation, particularly through secreted ADP.

PubMed

Selheim, F; Idsøe, R; Fukami, M H; Holmsen, H; Vassbotn, F S

1999-10-05

Platelet activation by thrombin or collagen results in secretion and synthesis of several platelet agonists that enhance the responses to the primary agonists (autocrine stimulation). To disclose the effects of thrombin and collagen on the phosphorylation of 3-phosphoinositides per se we incubated platelets with five inhibitors of platelet autocrine stimulation (IAS) that act extracellularly. We found that IAS almost totally blocked thrombin-induced production of phosphatidylinositol 3,4-bisphosphate [PtdIns(3,4)P(2)] and phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P(3)]. In contrast, collagen induced massive production of PtdIns(3,4)P(2) and PtdIns(3,4,5)P(3) in the presence of IAS. When testing the effect of each inhibitor individually we found the strongest inhibition of thrombin-induced PtdIns(3,4)P(2) production with the ADP scavenger system CP/CPK. Furthermore, we found a strong synergistic effect between exogenously added ADP and thrombin on production of PtdIns(3,4)P(2). In contrast to the results from 3-phosphorylated phosphoinositides, CP/CPK had little effect on thrombin-induced protein tyrosine phosphorylation. Our results show the importance of autocrine stimulation in thrombin-induced accumulation of 3-phosphorylated phosphoinositides and raise the question as to whether thrombin by itself is capable of inducing PI 3-K activation. In marked contrast to thrombin, collagen per se appears to be able to trigger increased production of PtdIns(3,4)P(2) and PtdIns(3,4,5)P(3). Copyright 1999 Academic Press.

Autocrine IL-6 mediates pituitary tumor senescence

PubMed Central

Fuertes, Mariana; Ajler, Pablo; Carrizo, Guillermo; Cervio, Andrés; Sevlever, Gustavo; Stalla, Günter K.; Arzt, Eduardo

2017-01-01

Cellular senescence is a stable proliferative arrest state. Pituitary adenomas are frequent and mostly benign, but the mechanism for this remains unknown. IL-6 is involved in pituitary tumor progression and is produced by the tumoral cells. In a cell autonomous fashion, IL-6 participates in oncogene-induced senescence in transduced human melanocytes. Here we prove that autocrine IL-6 participates in pituitary tumor senescence. Endogenous IL-6 inhibition in somatotroph MtT/S shRNA stable clones results in decreased SA-β-gal activity and p16INK4a but increased pRb, proliferation and invasion. Nude mice injected with IL-6 silenced clones develop tumors contrary to MtT/S wild type that do not, demonstrating that clones that escape senescence are capable of becoming tumorigenic. When endogenous IL-6 is silenced, cell cultures derived from positive SA-β-gal human tumor samples decrease the expression of the senescence marker. Our results establish that IL-6 contributes to maintain senescence by its autocrine action, providing a natural model of IL-6 mediated benign adenoma senescence. PMID:27902467

Cell-autonomous intracellular androgen receptor signaling drives the growth of human prostate cancer initiating cells.

PubMed

Vander Griend, Donald J; D'Antonio, Jason; Gurel, Bora; Antony, Lizamma; Demarzo, Angelo M; Isaacs, John T

2010-01-01

The lethality of prostate cancer is due to the continuous growth of cancer initiating cells (CICs) which are often stimulated by androgen receptor (AR) signaling. However, the underlying molecular mechanism(s) for such AR-mediated growth stimulation are not fully understood. Such mechanisms may involve cancer cell-dependent induction of tumor stromal cells to produce paracrine growth factors or could involve cancer cell autonomous autocrine and/or intracellular AR signaling pathways. We utilized clinical samples, animal models and a series of AR-positive human prostate cancer cell lines to evaluate AR-mediated growth stimulation of prostate CICs. The present studies document that stromal AR expression is not required for prostate cancer growth, since tumor stroma surrounding AR-positive human prostate cancer metastases (N = 127) are characteristically AR-negative. This lack of a requirement for AR expression in tumor stromal cells is also documented by the fact that human AR-positive prostate cancer cells grow equally well when xenografted in wild-type versus AR-null nude mice. AR-dependent growth stimulation was documented to involve secretion, extracellular binding, and signaling by autocrine growth factors. Orthotopic xenograft animal studies documented that the cellautonomous autocrine growth factors which stimulate prostate CIC growth are not the andromedins secreted by normal prostate stromal cells. Such cell autonomous and extracellular autocrine signaling is necessary but not sufficient for the optimal growth of prostate CICs based upon the response to anti-androgen plus/or minus preconditioned media. AR-induced growth stimulation of human prostate CICs requires AR-dependent intracellular pathways. The identification of such AR-dependent intracellular pathways offers new leads for the development of effective therapies for prostate cancer. (c) 2009 Wiley-Liss, Inc.

PGE2 is a UVR-inducible autocrine factor for human melanocytes that stimulates tyrosinase activation

PubMed Central

Starner, Renny J.; McClelland, Lindy; Abdel-Malek, Zalfa; Fricke, Alex; Scott, Glynis

2013-01-01

Melanocyte proliferation, dendrite formation, and pigmentation are controlled by paracrine factors, particularly following exposure to ultraviolet radiation (UVR). Little is known about autocrine factors for melanocytes. Prostaglandins activate signaling pathways involved in growth, differentiation and apoptosis. Prostaglandin E2 (PGE2) is the most abundant prostaglandin released by keratinocytes following UVR, and stimulates the formation of dendrites in melanocytes. Synthesis of PGE2 is controlled by cPLA2, which releases arachidonic acid from membranes, and COX-2 and prostaglandin E2 synthases (PGES), which convert arachidonic acid to PGH2 and PGH2 to PGE2, respectively. In this report we show that multiple irradiations of human melanocytes with UVR stimulates tyrosinase activity, independent of expression of a functional melanocortin 1 receptor, suggesting the presence of a non-melanocortin autocrine factor. Irradiation of melanocytes activated cPLA2, the rate-limiting step in eicosanoid synthesis, and stimulated PGE2 secretion. PGE2 increased cAMP production, tyrosinase activity and proliferation in melanocytes. PGE2 binds to four distinct G-protein coupled receptors (EP1–4). We show that EP4 receptor signaling stimulates cAMP production in melanocytes. Conversely, stimulation of the EP3 receptor lowered basal cAMP levels. These data suggest that relative levels or activity of these receptors controls effects of PGE2 on cAMP in melanocytes. The data are the first to identify PGE2 as an UVR-inducible autocrine factor for melanocytes that stimulates tyrosinase activity and proliferation, and to show that EP3 and EP4 receptor signaling have opposing effects on cAMP production, a critical signaling pathway that regulates proliferation and melanogenesis in melanocytes. PMID:20500768

Autocrine HBEGF expression promotes breast cancer intravasation, metastasis and macrophage-independent invasion in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Z. N.; Sharma, V. P.; Beaty, B. T.

2014-10-13

Increased expression of HBEGF in estrogen receptor-negative breast tumors is correlated with enhanced metastasis to distant organ sites and more rapid disease recurrence upon removal of the primary tumor. Our previous work has demonstrated a paracrine loop between breast cancer cells and macrophages in which the tumor cells are capable of stimulating macrophages through the secretion of colony-stimulating factor-1 while the tumor-associated macrophages (TAMs), in turn, aid in tumor cell invasion by secreting epidermal growth factor. To determine how the autocrine expression of epidermal growth factor receptor (EGFR) ligands by carcinoma cells would affect this paracrine loop mechanism, and inmore » particular whether tumor cell invasion depends on spatial ligand gradients generated by TAMs, we generated cell lines with increased HBEGF expression. We found that autocrine HBEGF expression enhanced in vivo intravasation and metastasis and resulted in a novel phenomenon in which macrophages were no longer required for in vivo invasion of breast cancer cells. In vitro studies revealed that expression of HBEGF enhanced invadopodium formation, thus providing a mechanism for cell autonomous invasion. The increased invadopodium formation was directly dependent on EGFR signaling, as demonstrated by a rapid decrease in invadopodia upon inhibition of autocrine HBEGF/EGFR signaling as well as inhibition of signaling downstream of EGFR activation. HBEGF expression also resulted in enhanced invadopodium function via upregulation of matrix metalloprotease 2 (MMP2) and MMP9 expression levels. We conclude that high levels of HBEGF expression can short-circuit the tumor cell/macrophage paracrine invasion loop, resulting in enhanced tumor invasion that is independent of macrophage signaling.« less

K-RAS(V12) Induces Autocrine Production of EGFR Ligands and Mediates Radioresistance Through EGFR-Dependent Akt Signaling and Activation of DNA-PKcs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minjgee, Minjmaa; Toulany, Mahmoud; Kehlbach, Rainer

2011-12-01

Purpose: It is known that postirradiation survival of tumor cells presenting mutated K-RAS is mediated through autocrine activation of epidermal growth factor receptor (EGFR). In this study the molecular mechanism of radioresistance of cells overexpressing mutated K-RAS(V12) was investigated. Methods and Materials: Head-and-neck cancer cells (FaDu) presenting wild-type K-RAS were transfected with empty vector or vector expressing mutated K-RAS(V12). The effect of K-RAS(V12) on autocrine production of EGFR ligands, activation of EGFR downstream pathways, DNA damage repair, and postirradiation survival was analyzed. Results: Conditioned medium collected from K-RAS(V12)-transfected cells enhanced activation of the phosphatidylinositol-3-kinase-Akt pathway and increased postirradiation survival ofmore » wild-type K-RAS parental cells when compared with controls. These effects were reversed by amphiregulin (AREG)-neutralizing antibody. In addition, secretion of the EGFR ligands AREG and transforming growth factor {alpha} was significantly increased upon overexpression of K-RAS(V12). Expression of mutated K-RAS(V12) resulted in an increase in radiation-induced DNA-dependent protein kinase catalytic subunit (DNA-PKcs) phosphorylation at S2056. This increase was accompanied by increased repair of DNA double-strand breaks. Abrogation of DNA-PKcs phosphorylation by serum depletion or AREG-neutralizing antibody underscored the role of autocrine production of EGFR ligands, namely, AREG, in regulating DNA-PKcs activation in K-RAS mutated cells. Conclusions: These data indicate that radioresistance of K-RAS mutated tumor cells is at least in part due to constitutive production of EGFR ligands, which mediate enhanced repair of DNA double-strand breaks through the EGFR-phosphatidylinositol-3-kinase-Akt cascade.« less

Eosinophils as a novel cell source of prostaglandin D2: autocrine role in allergic inflammation

PubMed Central

Luna-Gomes, Tatiana; Magalhães, Kelly G; Mesquita-Santos, Fabio P.; Bakker-Abreu, Ilka; Samico, Rafaela F.; Molinaro, Raphael; Calheiros, Andrea S.; Diaz, Bruno L.; Bozza, Patrícia T.

2011-01-01

Prostaglandin (PG)D2 is a key mediator of allergic inflammatory diseases that is mainly synthesized by mast cells, which constitutively express high levels of the terminal enzyme involved in PGD2 synthesis, the hematopoietic PGD synthase (H-PGDS). Here, we investigated whether eosinophils are also able to synthesize, and therefore, supply biologically active PGD2. PGD2 synthesis was evaluated within human blood eosinophils, in vitro-differentiated mouse eosinophils, and eosinophils infiltrating inflammatory site of mouse allergic reaction. Biological function of eosinophil-derived PGD2 was studied by employing inhibitors of synthesis and activity. Constitutive expression of H-PGDS was found within non-stimulated human circulating eosinophils. Acute stimulation of human eosinophils with A23187 (0.1 – 5 μM) evoked PGD2 synthesis, which was located at the nuclear envelope and was inhibited by pre-treatment with HQL-79 (10 μM), a specific H-PGDS inhibitor. Pre-stimulation of human eosinophils with arachidonic acid (AA; 10 μM) or human eotaxin (6 nM) also enhanced HQL-79-sensitive PGD2 synthesis, which, by acting on membrane-expressed specific receptors (DP1 and DP2), displayed an autocrine/paracrine ability to trigger leukotriene (LT)C4 synthesis and lipid body biogenesis, hallmark events of eosinophil activation. In vitro-differentiated mouse eosinophils also synthesized paracrine/autocrine active PGD2 in response to AA stimulation. In vivo, at late time point of the allergic reaction, infiltrating eosinophils found at the inflammatory site appeared as an auxiliary PGD2-synthesizing cell population. Our findings reveal that eosinophils are indeed able to synthesize and secrete PGD2, hence representing during allergic inflammation an extra cell source of PGD2, which functions as an autocrine signal for eosinophil activation. PMID:22102725

Rhythmic autocrine activity in cultured insect epidermal cells.

PubMed

Mesnier, M; Partiaoglou, N; Oberlander, H; Porcheron, P

2000-05-01

It is now well established that ecdysteroids can be produced in insects in the absence of prothoracic glands. In this respect, it has been shown that cells in culture can produce ecdysteroids. Our aims were: (1) to determine whether ecdysteroid target cells of epidermal origin could also be the source of ecdysteroids; (2) to monitor more accurately the kinetics of ecdysteroid production; and (3) to check for possible relationships between this synthetic activity and dynamics of cell division. An insect cell line (IAL-PID2) established from imaginal discs of the Indian meal moth, Plodia interpunctella, with wild-type sensitivity to ecdysteroids was used in our study. Our results showed that the Plodia cell line exhibited autocrine activity. When division of IAL-PID2 cells was synchronized, a rhythmic production of ecdysteroids was observed. However, further experiments indicated that this rhythmicity could be cell autonomous. This led us to anticipate the existence of two cell subpopulations that would be able to produce ecdysteroids rhythmically, a minor one that would be cell cycle serum-independent population, and a major population that would need serum growth factors to proliferate and produce ecdysteroids. Qualitative study of the ecdysteroid content of the media clearly showed that ecdysone was the major immunoreactive product. Taken together, our findings clearly show that an insect cell line of epidermal origin is capable of rhythmic autocrine production of ecdysteroids. These results support the hypothesis that alternate sites for ecdysteroid production in vivo may exist and could play a role in local regulation of development. We now plan to determine the cellular basis of this rhythmic autocrine activity and to confirm the existence of growth factor-autonomous cells in the culture as well as the potent role played by ecdysteroids in the cross-talk between various cell subpopulations. Copyright 2000 Wiley-Liss, Inc.

Curcumin inhibits autocrine growth hormone-mediated invasion and metastasis by targeting NF-κB signaling and polyamine metabolism in breast cancer cells.

PubMed

Coker-Gurkan, Ajda; Celik, Merve; Ugur, Merve; Arisan, Elif-Damla; Obakan-Yerlikaya, Pinar; Durdu, Zeynep Begum; Palavan-Unsal, Narcin

2018-05-16

Curcumin is assumed to be a plant-derived therapeutic drug that triggers apoptotic cell death in vitro and in vivo by affecting different molecular targets such as NF-κB. Phase I/II trial of curcumin alone or with chemotherapeutic drugs has been accomplished in pancreatic, colon, prostate and breast cancer cases. Recently, autocrine growth hormone (GH) signaling-induced cell growth, metastasis and drug resistance have been demonstrated in breast cancer. In this study, our aim was to investigate the potential therapeutic effect of curcumin by evaluating the molecular machinery of curcumin-triggered apoptotic cell death via focusing on NF-κB signaling and polyamine (PA) metabolism in autocrine GH-expressing MCF-7, MDA-MB-453 and MDA-MB-231 breast cancer cells. For this purpose, a pcDNA3.1 (+) vector with a GH gene insert was transfected by a liposomal agent in all breast cancer cells and then selection was conducted in neomycin (G418) included media. Autocrine GH-induced curcumin resistance was overcome in a dose-dependent manner and curcumin inhibited cell proliferation, invasion-metastasis and phosphorylation of p65 (Ser536), and thereby partly prevented its DNA binding activity in breast cancer cells. Moreover, curcumin induced caspase-mediated apoptotic cell death by activating the PA catabolic enzyme expressions, which led to generation of toxic by-products such as H 2 O 2 in MCF-7, MDA-MB-453 and MDA-MB-231 GH+ breast cancer cells. In addition, transient silencing of SSAT prevented curcumin-induced cell viability loss and apoptotic cell death in each breast cancer cells. In conclusion, curcumin could overcome the GH-mediated resistant phenotype via modulating cell survival, death-related signaling routes and activating PA catabolic pathway.

Neurotensin is an autocrine trophic factor stimulated by androgen withdrawal in human prostate cancer.

PubMed Central

Sehgal, I; Powers, S; Huntley, B; Powis, G; Pittelkow, M; Maihle, N J

1994-01-01

After therapeutic hormone deprivation, prostate cancer cells often develop androgen-insensitive growth through mechanisms thus far undefined. Neuropeptides have been previously implicated as growth factors in some prostate cancers. Here, we demonstrate that androgen-sensitive LNCaP human prostate cancer cells produce and secrete neurotensin following androgen withdrawal. We show that while LNCaP cells express the neurotensin receptor, only androgen-deprived cells exhibit a growth response to exogenous neurotensin. We further demonstrate that androgen-stimulated cells may be refractory to exogenous neurotensin due to androgen induction of a metalloprotease active toward neurotensin. Thus, prostate cancer cells deprived of androgen develop an alternative autocrine growth mechanism involving neurotensin. Images PMID:8197117

Endothelin-3 production by human rhabdomyosarcoma: a possible new marker with a paracrine role.

PubMed

Palladini, Arianna; Astolfi, Annalisa; Croci, Stefania; De Giovanni, Carla; Nicoletti, Giordano; Rosolen, Angelo; Sartori, Francesca; Lollini, Pier-Luigi; Landuzzi, Lorena; Nanni, Patrizia

2006-03-01

Several autocrine and paracrine growth factor circuits have been found in human rhabdomyosarcoma cells. In this study we show that endothelin-3 (ET-3), a vasoactive peptide, is produced by human rhabdomyosarcoma cell lines, whereas it is not expressed by human sarcoma cell lines of non-muscle origin. We did not find evidence of a significant autocrine loop; nevertheless ET-3 produced by rhabdomyosarcoma cells can act as a paracrine factor, since it promotes migration of endothelial cells. Moreover ET-3 is present in plasma of mice bearing xenografts of human rhabdomyosarcoma cells, and may be potential new marker of the human rhabdomyosarcoma to be studied further.

Autocrine and paracrine Shh signaling are necessary for tooth morphogenesis, but not tooth replacement in snakes and lizards (Squamata).

PubMed

Handrigan, Gregory R; Richman, Joy M

2010-01-01

Here we study the role of Shh signaling in tooth morphogenesis and successional tooth initiation in snakes and lizards (Squamata). By characterizing the expression of Shh pathway receptor Ptc1 in the developing dentitions of three species (Eublepharis macularius, Python regius, and Pogona vitticeps) and by performing gain- and loss-of-function experiments, we demonstrate that Shh signaling is active in the squamate tooth bud and is required for its normal morphogenesis. Shh apparently mediates tooth morphogenesis by separate paracrine- and autocrine-mediated functions. According to this model, paracrine Shh signaling induces cell proliferation in the cervical loop, outer enamel epithelium, and dental papilla. Autocrine signaling within the stellate reticulum instead appears to regulate cell survival. By treating squamate dental explants with Hh antagonist cyclopamine, we induced tooth phenotypes that closely resemble the morphological and differentiation defects of vestigial, first-generation teeth in the bearded dragon P. vitticeps. Our finding that these vestigial teeth are deficient in epithelial Shh signaling further corroborates that Shh is needed for the normal development of teeth in snakes and lizards. Finally, in this study, we definitively refute a role for Shh signaling in successional dental lamina formation and conclude that other pathways regulate tooth replacement in squamates.

Local bone marrow renin-angiotensin system in primitive, definitive and neoplastic haematopoiesis.

PubMed

Haznedaroglu, Ibrahim C; Beyazit, Yavuz

2013-03-01

The locally active ligand peptides, mediators, receptors and signalling pathways of the haematopoietic BM (bone marrow) autocrine/paracrine RAS (renin-angiotensin system) affect the essential steps of definitive blood cell production. Haematopoiesis, erythropoiesis, myelopoiesis, formation of monocytic and lymphocytic lineages, thrombopoiesis and other stromal cellular elements are regulated by the local BM RAS. The local BM RAS is present and active even in primitive embryonic haematopoiesis. ACE (angiotensin-converting enzyme) is expressed on the surface of the first endothelial and haematopoietic cells, forming the marrow cavity in the embryo. ACE marks early haematopoietic precursor cells and long-term blood-forming CD34(+) BM cells. The local autocrine tissue BM RAS may also be active in neoplastic haematopoiesis. Critical RAS mediators such as renin, ACE, AngII (angiotensin II) and angiotensinogen have been identified in leukaemic blast cells. The local tissue RAS influences tumour growth and metastases in an autocrine and paracrine fashion via the modulation of numerous carcinogenic events, such as angiogenesis, apoptosis, cellular proliferation, immune responses, cell signalling and extracellular matrix formation. The aim of the present review is to outline the known functions of the local BM RAS within the context of primitive, definitive and neoplastic haematopoiesis. Targeting the actions of local RAS molecules could represent a valuable therapeutic option for the management of neoplastic disorders.

Control of adipogenesis by the autocrine interplays between angiotensin 1-7/Mas receptor and angiotensin II/AT1 receptor signaling pathways.

PubMed

Than, Aung; Leow, Melvin Khee-Shing; Chen, Peng

2013-05-31

Angiotensin II (AngII), a peptide hormone released by adipocytes, can be catabolized by adipose angiotensin-converting enzyme 2 (ACE2) to form Ang(1-7). Co-expression of AngII receptors (AT1 and AT2) and Ang(1-7) receptors (Mas) in adipocytes implies the autocrine regulation of the local angiotensin system upon adipocyte functions, through yet unknown interactive mechanisms. In the present study, we reveal the adipogenic effects of Ang(1-7) through activation of Mas receptor and its subtle interplays with the antiadipogenic AngII-AT1 signaling pathways. Specifically, in human and 3T3-L1 preadipocytes, Ang(1-7)-Mas signaling promotes adipogenesis via activation of PI3K/Akt and inhibition of MAPK kinase/ERK pathways, and Ang(1-7)-Mas antagonizes the antiadipogenic effect of AngII-AT1 by inhibiting the AngII-AT1-triggered MAPK kinase/ERK pathway. The autocrine regulation of the AngII/AT1-ACE2-Ang(1-7)/Mas axis upon adipogenesis has also been revealed. This study suggests the importance of the local regulation of the delicately balanced angiotensin system upon adipogenesis and its potential as a novel therapeutic target for obesity and related metabolic disorders.

Autocrine stimulation of IL-10 is critical to the enrichment of IL-10-producing CD40(hi)CD5(+) regulatory B cells in vitro and in vivo.

PubMed

Kim, Hyuk Soon; Lee, Jun Ho; Han, Hee Dong; Kim, A-Ram; Nam, Seung Taek; Kim, Hyun Woo; Park, Young Hwan; Lee, Dajeong; Lee, Min Bum; Park, Yeong Min; Kim, Hyung Sik; Kim, Young Mi; You, Ji Chang; Choi, Wahn Soo

2015-01-01

IL-10-producing B (Breg) cells regulate various immune responses. However, their phenotype remains unclear. CD40 expression was significantly increased in B cells by LPS, and the Breg cells were also enriched in CD40(hi)CD5(+) B cells. Furthermore, CD40 expression on Breg cells was increased by IL-10, CD40 ligand, and B cell-activating factor, suggesting that CD40(hi) is a common phenotype of Breg cells. LPS-induced CD40 expression was largely suppressed by an anti-IL-10 receptor antibody and in IL-10(-/-)CD5(+)CD19(+) B cells. The autocrine effect of IL-10 on the CD40 expression was largely suppressed by an inhibitor of JAK/STAT3. In vivo, the LPS treatment increased the population of CD40(hi)CD5(+) Breg cells in mice. However, the population of CD40(hi)CD5(+) B cells was minimal in IL-10(-/-) mice by LPS. Altogether, our findings show that Breg cells are largely enriched in CD40(hi)CD5(+) B cells and the autocrine effect of IL-10 is critical to the formation of CD40(hi)CD5(+) Breg cells.

Intracellular autocrine VEGF signaling promotes EBDC cell proliferation, which can be inhibited by Apatinib.

PubMed

Peng, Sui; Zhang, Yanyan; Peng, Hong; Ke, Zunfu; Xu, Lixia; Su, Tianhong; Tsung, Allan; Tohme, Samer; Huang, Hai; Zhang, Qiuyang; Lencioni, Riccardo; Zeng, Zhirong; Peng, Baogang; Chen, Minhu; Kuang, Ming

2016-04-10

Tumor cells produce vascular endothelial growth factor (VEGF) which can interact with membrane or cytoplasmic VEGF receptors (VEGFRs) to promote cell growth. We aimed to investigate the role of extracellular/intracellular autocrine VEGF signaling and Apatinib, a highly selective VEGFR2 inhibitor, in extrahepatic bile duct cancer (EBDC). We found conditioned medium or recombinant human VEGF treatment promoted EBDC cell proliferation through a phospholipase C-γ1-dependent pathway. This pro-proliferative effect was diminished by VEGF, VEGFR1 or VEGFR2 neutralizing antibodies, but more significantly suppressed by intracellular VEGFR inhibitor. The rhVEGF induced intracellular VEGF signaling by promoting nuclear accumulation of pVEGFR1/2 and enhancing VEGF promoter activity, mRNA and protein expression. Internal VEGFR2 inhibitor Apatinib significantly inhibited intracellular VEGF signaling, suppressed cell proliferation in vitro and delayed xenograft tumor growth in vivo, while anti-VEGF antibody Bevacizumab showed no effect. Clinically, overexpression of pVEGFR1 and pVEGFR2 was significantly correlated with poorer overall survival (P = .007 and P = .020, respectively). In conclusion, the intracellular autocrine VEGF loop plays a predominant role in VEGF-induced cell proliferation. Apatinib is an effective intracellular VEGF pathway blocker that presents a great therapeutic potential in EBDC. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Functional Erythropoietin Autocrine Loop in Melanoma

PubMed Central

Kumar, Suresh M.; Acs, Geza; Fang, Dong; Herlyn, Meenhard; Elder, David E.; Xu, Xiaowei

2005-01-01

Although erythropoietin (Epo) is a known stimulator of erythropoiesis, recent evidence suggests that its biological functions are not confined to hematopoietic cells. To elucidate the role of Epo and erythropoietin receptor (EpoR) in melanoma, we examined the expression and function of these proteins in melanocytes and melanoma cells. We found increased expression of Epo in melanoma cells compared to melanocyte in vitro. EpoR was also strongly expressed in all of the melanoma cell lines and two of the three melanocyte cell lines examined. Epo expression was significantly higher in melanoma than in benign nevi as determined by immunohistochemistry. Although melanoma cells secreted Epo in normoxic condition in vitro, hypoxia and CoCl2 treatment increased Epo secretion. EpoR in melanoma cells was functional, because exogenous Epo increased melanoma resistance to hypoxic stress, pretreatment of melanoma cells with Epo significantly increased resistance to dacarbazine treatment, and Epo increased the phosphorylation of EpoR, RAF, and MEK. In conclusion, we demonstrated constitutive expression of Epo and EpoR as well as autonomous secretion of Epo by melanoma cells, indicating a novel autocrine loop of Epo in melanoma. The results suggest that the autocrine and paracrine functions of Epo might play a role in malignant transformation of melanocytes and in the survival of melanoma cells in hypoxia and other adverse conditions. PMID:15743794

Regulation of Dense-Core Granule Replenishment by Autocrine BMP Signalling in Drosophila Secondary Cells.

PubMed

Redhai, Siamak; Hellberg, Josephine E E U; Wainwright, Mark; Perera, Sumeth W; Castellanos, Felix; Kroeger, Benjamin; Gandy, Carina; Leiblich, Aaron; Corrigan, Laura; Hilton, Thomas; Patel, Benjamin; Fan, Shih-Jung; Hamdy, Freddie; Goberdhan, Deborah C I; Wilson, Clive

2016-10-01

Regulated secretion by glands and neurons involves release of signalling molecules and enzymes selectively concentrated in dense-core granules (DCGs). Although we understand how many secretagogues stimulate DCG release, how DCG biogenesis is then accelerated to replenish the DCG pool remains poorly characterised. Here we demonstrate that each prostate-like secondary cell (SC) in the paired adult Drosophila melanogaster male accessory glands contains approximately ten large DCGs, which are loaded with the Bone Morphogenetic Protein (BMP) ligand Decapentaplegic (Dpp). These DCGs can be marked in living tissue by a glycophosphatidylinositol (GPI) lipid-anchored form of GFP. In virgin males, BMP signalling is sporadically activated by constitutive DCG secretion. Upon mating, approximately four DCGs are typically released immediately, increasing BMP signalling, primarily via an autocrine mechanism. Using inducible knockdown specifically in adult SCs, we show that secretion requires the Soluble NSF Attachment Protein, SNAP24. Furthermore, mating-dependent BMP signalling not only promotes cell growth, but is also necessary to accelerate biogenesis of new DCGs, restoring DCG number within 24 h. Our analysis therefore reveals an autocrine BMP-mediated feedback mechanism for matching DCG release to replenishment as secretion rates fluctuate, and might explain why in other disease-relevant systems, like pancreatic β-cells, BMP signalling is also implicated in the control of secretion.

Regulation of Dense-Core Granule Replenishment by Autocrine BMP Signalling in Drosophila Secondary Cells

PubMed Central

Redhai, Siamak; Hellberg, Josephine E. E. U.; Wainwright, Mark; Perera, Sumeth W.; Castellanos, Felix; Kroeger, Benjamin; Gandy, Carina; Leiblich, Aaron; Corrigan, Laura; Hilton, Thomas; Patel, Benjamin; Fan, Shih-Jung; Hamdy, Freddie; Goberdhan, Deborah C. I.

2016-01-01

Regulated secretion by glands and neurons involves release of signalling molecules and enzymes selectively concentrated in dense-core granules (DCGs). Although we understand how many secretagogues stimulate DCG release, how DCG biogenesis is then accelerated to replenish the DCG pool remains poorly characterised. Here we demonstrate that each prostate-like secondary cell (SC) in the paired adult Drosophila melanogaster male accessory glands contains approximately ten large DCGs, which are loaded with the Bone Morphogenetic Protein (BMP) ligand Decapentaplegic (Dpp). These DCGs can be marked in living tissue by a glycophosphatidylinositol (GPI) lipid-anchored form of GFP. In virgin males, BMP signalling is sporadically activated by constitutive DCG secretion. Upon mating, approximately four DCGs are typically released immediately, increasing BMP signalling, primarily via an autocrine mechanism. Using inducible knockdown specifically in adult SCs, we show that secretion requires the Soluble NSF Attachment Protein, SNAP24. Furthermore, mating-dependent BMP signalling not only promotes cell growth, but is also necessary to accelerate biogenesis of new DCGs, restoring DCG number within 24 h. Our analysis therefore reveals an autocrine BMP-mediated feedback mechanism for matching DCG release to replenishment as secretion rates fluctuate, and might explain why in other disease-relevant systems, like pancreatic β-cells, BMP signalling is also implicated in the control of secretion. PMID:27727275

Caveolin-1 regulates lipid droplet metabolism in endothelial cells via autocrine prostacyclin-stimulated, cAMP-mediated lipolysis.

PubMed

Kuo, Andrew; Lee, Monica Y; Yang, Kui; Gross, Richard W; Sessa, William C

2018-01-19

Lipid droplets (LD) are dynamic organelles involved in intracellular lipid metabolism in almost all eukaryotic cells, and LD-associated proteins tightly regulate their dynamics. One LD coat protein is caveolin-1 (Cav-1), an essential component for caveola assembly in highly differentiated cells, including adipocytes, smooth muscle cells, and endothelial cells (EC). However, the role of Cav-1 in LD dynamics is unclear. Here we report that EC lacking Cav-1 exhibit impaired LD formation. The decreased LD formation is due to enhanced lipolysis and not caused by reduced triglyceride synthesis or fatty acid uptake. Mechanistically, the absence of Cav-1 increased cAMP/PKA signaling in EC, as indicated by elevated phosphorylation of hormone-sensitive lipase and increased lipolysis. Unexpectedly, we also observed enhanced autocrine production of prostaglandin I 2 (PGI 2 , also called prostacyclin) in Cav-1 KO EC, and this PGI 2 increase appeared to stimulate cAMP/PKA pathways, contributing to the enhanced lipolysis in Cav-1 KO cells. Our results reveal an unanticipated role of Cav-1 in regulating lipolysis in non-adipose tissue, indicating that Cav-1 is required for LD metabolism in EC and that it regulates cAMP-dependent lipolysis in part via the autocrine production of PGI 2 .

Mesenchymal stem cells expressing insulin-like growth factor-I (MSCIGF) promote fracture healing and restore new bone formation in Irs1 knockout mice: analyses of MSCIGF autocrine and paracrine regenerative effects.

PubMed

Granero-Moltó, Froilán; Myers, Timothy J; Weis, Jared A; Longobardi, Lara; Li, Tieshi; Yan, Yun; Case, Natasha; Rubin, Janet; Spagnoli, Anna

2011-10-01

Failures of fracture repair (nonunions) occur in 10% of all fractures. The use of mesenchymal stem cells (MSC) in tissue regeneration appears to be rationale, safe, and feasible. The contributions of MSC to the reparative process can occur through autocrine and paracrine effects. The primary objective of this study is to find a novel mean, by transplanting primary cultures of bone marrow-derived MSCs expressing insulin-like growth factor-I (MSC(IGF)), to promote these seed-and-soil actions of MSC to fully implement their regenerative abilities in fracture repair and nonunions. MSC(IGF) or traceable MSC(IGF)-Lac-Z were transplanted into wild-type or insulin-receptor-substrate knockout (Irs1(-/-)) mice with a stabilized tibia fracture. Healing was assessed using biomechanical testing, microcomputed tomography (μCT), and histological analyses. We found that systemically transplanted MSC(IGF) through autocrine and paracrine actions improved the fracture mechanical strength and increased new bone content while accelerating mineralization. We determined that IGF-I adapted the response of transplanted MSC(IGF) to promote their differentiation into osteoblasts. In vitro and in vivo studies showed that IGF-I-induced osteoglastogenesis in MSCs was dependent of an intact IRS1-PI3K signaling. Furthermore, using Irs1(-/-) mice as a nonunion fracture model through altered IGF signaling, we demonstrated that the autocrine effect of IGF-I on MSC restored the fracture new bone formation and promoted the occurrence of a well-organized callus that bridged the gap. A callus that was basically absent in Irs1(-/-) left untransplanted or transplanted with MSCs. We provided evidence of effects and mechanisms for transplanted MSC(IGF) in fracture repair and potentially to treat nonunions. Copyright © 2011 AlphaMed Press.

Autocrine-Derived Epidermal Growth Factor Receptor Ligands Contribute to Recruitment of Tumor-Associated Macrophage and Growth of Basal Breast Cancer Cells In Vivo

PubMed Central

Nickerson, Nicole K.; Mill, Christopher P.; Wu, Hsin-Jung; Riese, David J.; Foley, John

2014-01-01

Epidermal growth factor receptor (EGFR) expression has been linked to progression of basal breast cancers. Many breast cancer cells harbor the EGFR and produce its family of ligands, suggesting they may participate in autocrine and paracrine signaling with cells of the tumor microenvironment. EGFR ligand expression was profiled in the basal breast cancer cell line MDA-231 where AREG, TGF-α, and HBEGF were the three ligands most highly expressed. Autocrine signaling was modulated through silencing or overexpression of these three ligands using lentiviral constructs and the impact measured using motility, proliferation, and cytokine expression assays. Changes in receptor phosphorylation and receptor turnover were examined. Knockdown of AREG or TGF-α in vitro resulted in decreased motility (p < 0.05) and decreased expression of macrophage chemoattractants. Overexpression of TGF-α increased motility and chemoattractant expression, whereas AREG did not. HBEGF modulation had no effect on any cellular behaviors. All the cells with altered ligand production were inoculated into female athymic nude mice to form mammary fat pad tumors, followed by immunohistochemical analysis for necrosis, angiogenesis, and macrophage recruitment. In vivo, knockdown of AREG or TGF-α increased survival (p < 0.001) while decreasing angiogenesis (p < 0.001), tumor growth (p < 0.001), and macrophage attraction (p < 0.001). Overexpression of AREG appeared to elicit a greater effect than TGF-α on mammary fat pad tumor growth by increasing angiogenesis (p < 0.001) and macrophage attraction to the tumor (p < 0.01). We propose these changes in mammary tumor growth were the result of increased recruitment of macrophages to the tumor by cells with altered autocrine EGFR signaling. We conclude that AREG and TGF-α were somewhat interchangeable in their effects on EGFR signaling; however, TGF-α had a greater effect in vitro and AREG had a greater effect in vivo. PMID:23879171

Autocrine-derived epidermal growth factor receptor ligands contribute to recruitment of tumor-associated macrophage and growth of basal breast cancer cells in vivo.

PubMed

Nickerson, Nicole K; Mill, Christopher P; Wu, Hsin-Jung; Riese, David J; Foley, John

2013-01-01

Epidermal growth factor receptor (EGFR) expression has been linked to progression of basal breast cancers. Many breast cancer cells harbor the EGFR and produce its family of ligands, suggesting they may participate in autocrine and paracrine signaling with cells of the tumor microenvironment. EGFR ligand expression was profiled in the basal breast cancer cell line MDA-231 where AREG, TGF-alpha, and HBEGF were the three ligands most highly expressed. Autocrine signaling was modulated through silencing or overexpression of these three ligands using lentiviral constructs and the impact measured using motility, proliferation, and cytokine expression assays. Changes in receptor phosphorylation and receptor turnover were examined. Knockdown of AREG or TGF-alpha in vitro resulted in decreased motility (p < 0.05) and decreased expression of macrophage chemoattractants. Overexpression of TGF-alpha increased motility and chemoattractant expression, whereas AREG did not. HBEGF modulation had no effect on any cellular behaviors. All the cells with altered ligand production were inoculated into female athymic nude mice to form mammary fat pad tumors, followed by immunohistochemical analysis for necrosis, angiogenesis, and macrophage recruitment. In vivo, knockdown of AREG or TGF-alpha increased survival (p < 0.001) while decreasing angiogenesis (p < 0.001), tumor growth (p < 0.001), and macrophage attraction (p < 0.001). Overexpression of AREG appeared to elicit a greater effect than TGF-alpha on mammary fat pad tumor growth by increasing angiogenesis (p < 0.001) and macrophage attraction to the tumor (p < 0.01). We propose these changes in mammary tumor growth were the result of increased recruitment of macrophages to the tumor by cells with altered autocrine EGFR signaling. We conclude that AREG and TGF-alpha were somewhat interchangeable in their effects on EGFR signaling; however, TGF-alpha had a greater effect in vitro and AREG had a greater effect in vivo.

Epiregulin (EREG) is upregulated through an IL-1β autocrine loop in Caco-2 epithelial cells with reduced CFTR function.

PubMed

Massip-Copiz, Macarena; Clauzure, Mariángeles; Valdivieso, Ángel G; Santa-Coloma, Tomás A

2018-03-01

CFTR is a cAMP-regulated chloride channel, whose mutations produce cystic fibrosis. The impairment of CFTR activity increases the intracellular Cl - concentration, which in turn produces an increased interleukin-1β (IL-1β) secretion. The secreted IL-1β then induces an autocrine positive feedback loop, further stimulating IL-1β priming and secretion. Since IL-1β can transactivate the epidermal growth factor receptor (EGFR), we study here the levels of expression for different EGFR ligands in Caco-2/pRS26 cells (expressing shRNA against CFTR resulting in a reduced CFTR expression and activity). The epiregulin (EREG), amphiregulin (AREG), and heparin binding EGF like growth factor (HBEGF) mRNAs, were found overexpressed in Caco-2/pRS26 cells. The EREG mRNA had the highest differential expression and was further characterized. In agreement with its mRNA levels, Western blots (WB) showed increased EREG levels in CFTR-impaired cells. In addition, EREG mRNA and protein levels were stimulated by incubation with exogenous IL-1β and inhibited by the Interleukin 1 receptor type I (IL1R1) antagonist IL1RN, suggesting that the overexpression of EREG is a consequence of the autocrine IL-1β loop previously described for these cells. In addition, the JNK inhibitor SP600125, and the EGFR inhibitors AG1478 and PD168393, also had an inhibitory effect on EREG expression, suggesting that EGFR, activated in Caco-2/pRS26 cells, is involved in the observed EREG upregulation. In conclusion, in Caco-2 CFTR-shRNA cells, the EGFR ligand EREG is overexpressed due to an active IL-1β autocrine loop that indirectly activates EGFR, constituting new signaling effectors for the CFTR signaling pathway, downstream of CFTR, Cl - , and IL-1β. © 2017 Wiley Periodicals, Inc.

Loss of muscleblind-like 1 promotes invasive mesenchyme formation in endocardial cushions by stimulating autocrine TGFβ3

PubMed Central

2012-01-01

Background Valvulogenesis and septation in the developing heart depend on the formation and remodeling of endocardial cushions in the atrioventricular canal (AVC) and outflow tract (OFT). These cushions are invaded by a subpopulation of endocardial cells that undergo an epithelial-mesenchymal transition in response to paracrine and autocrine transforming growth factor β (TGFβ) signals. We previously demonstrated that the RNA binding protein muscleblind-like 1 (MBNL1) is expressed specifically in the cushion endocardium, and knockdown of MBNL1 in stage 14 embryonic chicken AVC explants enhances TGFβ-dependent endocardial cell invasion. Results In this study, we demonstrate that the effect of MBNL1 knockdown on invasion remains dependent on TGFβ3 after it is no longer required to induce basal levels of invasion. TGFβ3, but not TGFβ2, levels are elevated in medium conditioned by MBNL1-depleted AVC explants. TGFβ3 is elevated even when the myocardium is removed, indicating that MBNL1 modulates autocrine TGFβ3 production in the endocardium. More TGFβ3-positive cells are observed in the endocardial monolayer following MBNL1 knockdown. Addition of exogenous TGFβ3 to AVC explants recapitulates the effects of MBNL1 knockdown. Time course experiments demonstrate that knockdown of MBNL1 induces precocious TGFβ3 secretion, and early exposure to excess TGFβ3 induces precocious invasion. MBNL1 expression precedes TGFβ3 in the AVC endocardium, consistent with a role in preventing precocious autocrine TGFβ3 signaling. The stimulatory effects of MBNL1 knockdown on invasion are lost in stage 16 AVC explants. Knockdown of MBNL1 in OFT explants similarly enhances cell invasion, but not activation. TGFβ is necessary and sufficient to mediate this effect. Conclusions Taken together, these data support a model in which MBNL1 negatively regulates cell invasion in the endocardial cushions by restricting the magnitude and timing of endocardial-derived TGFβ3 production. PMID:22866814

Aggressive melanoma cells escape from BMP7-mediated autocrine growth inhibition through coordinated Noggin upregulation

PubMed Central

Hsu, Mei-Yu; Rovinsky, Sherry; Lai, Chiou-Yan; Qasem, Shadi; Liu, Xiaoming; How, Joan; Engelhardt, John F.; Murphy, George F.

2009-01-01

Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily responsible for mediating a diverse array of cellular functions both during embryogenesis and in adult life. Previously, we reported that upregulation of BMP7 in human melanoma correlates with tumor progression. However, melanoma cells are either inhibited by or become resistant to BMP7 as a function of tumor progression, with normal melanocytes being most susceptible. Herein, real-time quantitative reverse transcriptase-polymerase chain reactions and Western blotting revealed that the expression of BMP antagonist, Noggin, correlates with resistance to BMP7 in advanced melanoma cells. To test the hypothesis that coordinated upregulation of Noggin protects advanced melanoma cells from autocrine inhibition by BMP7, functional expression of Noggin in susceptible melanoma cells was achieved by adenoviral gene transfer. The Noggin-overexpressing cells exhibited a growth advantage in response to subsequent BMP7 transduction in vitro under anchorage-dependent and -independent conditions, in three-dimensional skin reconstructs, as well as in vivo in severe combined immune-deficiency mice. In concordance, Noggin knockdown by lentiviral shRNA confers sensitivity to BMP7-induced growth inhibition in advanced melanoma cells. Our findings suggest that, like TGF-β, BMP7 acts as an autocrine growth inhibitor in melanocytic cells, and that advanced melanoma cells may escape from BMP7-induced inhibition through concomitant aberrant expression of Noggin. PMID:18560367

Connective tissue growth factor and β-catenin constitute an autocrine loop for activation in rat sarcomatoid mesothelioma.

PubMed

Jiang, Li; Yamashita, Yoriko; Chew, Shan-Hwu; Akatsuka, Shinya; Ukai, Shun; Wang, Shenqi; Nagai, Hirotaka; Okazaki, Yasumasa; Takahashi, Takashi; Toyokuni, Shinya

2014-08-01

Due to the formerly widespread use of asbestos, malignant mesothelioma (MM) is increasingly frequent worldwide. MM is classified into epithelioid (EM), sarcomatoid (SM), and biphasic subtypes. SM is less common than EM but is recognized as the most aggressive type of MM, and these patients have a poor prognosis. To identify genes responsible for the aggressiveness of SM, we induced EM and SM in rats, using asbestos, and compared their transcriptomes. Based on the results, we focused on connective tissue growth factor (Ctgf), whose expression was significantly increased in SM compared with EM; EM itself exhibited an increased expression of Ctgf compared with normal mesothelium. Particularly in SM, Ctgf was a major regulator of MM proliferation and invasion through activation of the β-catenin-TCF-LEF signalling pathway, which is autocrine and formed a positive feedback loop via LRP6 as a receptor for secreted Ctgf. High Ctgf expression also played a role in the epithelial-mesenchymal transition in MM. Furthermore, Ctgf is a novel serum biomarker for both early diagnosis and determining the MM prognosis in rats. These data link Ctgf to SM through the LRP6-GSK3β-β-catenin-TCF-Ctgf autocrine axis and suggest Ctgf as a therapeutic target. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Effects of silibinin on growth and invasive properties of human ovarian carcinoma cells through suppression of heregulin/HER3 pathway.

PubMed

Momeny, Majid; Ghasemi, Reza; Valenti, Giovanni; Miranda, Mariska; Zekri, Ali; Zarrinrad, Ghazaleh; Javadikooshesh, Sepehr; Yaghmaie, Marjan; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir; Ghaffari, Seyed H

2016-03-01

Epithelial ovarian cancer (EOC) is the most fatal gynecological malignancy due to its high proliferative and invasive capacities. A heregulin (HRG)/HER3 autocrine loop increases proliferative and metastatic properties of EOC cells, suggesting that modulators of this signaling pathway may prove effective to trammel growth and motility of these cells. This study aimed to evaluate the effects of multi-tyrosine kinase inhibitor silibinin on proliferative and invasive characteristics of EOC cell lines OVCAR8 and SKOV3 through suppression of the HRG/HER3 pathway. To achieve this, the effects of silibinin on proliferation, DNA synthesis, clonogenicity, cell cycle progression, cathepsin B enzymatic activity, and migration and invasion were explored in vitro. Silibinin suppressed proliferation, DNA synthesis, and clonogenic abilities of OVCAR8 and SKOV3 cells through inhibition of the autocrine HRG/HER3 circuit. Silibinin-mediated attenuation of the HER3 signaling disabled the HER3/AKT/survivin axis and thereby, induced G1/S cell cycle arrest. Furthermore, silibinin reduced invasive potentials of the EOC cells through quelling the HRG/HER3 pathway and suppression of cathepsin B activity. Altogether, these results suggest that silibinin is a potential anti-cancer drug to inhibit proliferative and invasive characteristics of the EOC cells that exhibit an autocrine HRG/HER3 pathway.

Arsenite evokes IL-6 secretion, autocrine regulation of STAT3 signaling, and miR-21 expression, processes involved in the EMT and malignant transformation of human bronchial epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Fei; Xu, Yuan; The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University

2013-11-15

Arsenite is an established human carcinogen, and arsenite-induced inflammation contributes to malignant transformation of cells, but the molecular mechanisms by which cancers are produced remain to be established. The present results showed that, evoked by arsenite, secretion of interleukin-6 (IL-6), a pro-inflammatory cytokine, led to the activation of STAT3, a transcription activator, and to increased levels of a microRNA, miR-21. Blocking IL-6 with anti-IL-6 antibody and inhibiting STAT3 activation reduced miR-21 expression. For human bronchial epithelial cells, cultured in the presence of anti-IL-6 antibody for 3 days, the arsenite-induced EMT and malignant transformation were reversed. Thus, IL-6, acting on STAT3more » signaling, which up-regulates miR-21in an autocrine manner, contributes to the EMT induced by arsenite. These data define a link from inflammation to EMT in the arsenite-induced malignant transformation of HBE cells. This link, mediated through miRNAs, establishes a mechanism for arsenite-induced lung carcinogenesis. - Highlights: • Arsenite evokes IL-6 secretion. • IL-6 autocrine mediates STAT3 signaling and up-regulates miR-21expression. • Inflammation is involved in arsenite-induced EMT.« less

Modulation of c-fms proto-oncogene in an ovarian carcinoma cell line by a hammerhead ribozyme.

PubMed Central

Yokoyama, Y.; Morishita, S.; Takahashi, Y.; Hashimoto, M.; Tamaya, T.

1997-01-01

Co-expression of macrophage colony-stimulating factor (M-CSF) and its receptor (c-fms) is often found in ovarian epithelial carcinoma, suggesting the existence of autocrine regulation of cell growth by M-CSF. To block this autocrine loop, we have developed hammerhead ribozymes against c-fms mRNA. As target sites of the ribozyme, we chose the GUC sequence in codon 18 and codon 27 of c-fms mRNA. Two kinds of ribozymes were able to cleave an artificial c-fms RNA substrate in a cell-free system, although the ribozyme against codon 18 was much more efficient than that against codon 27. We next constructed an expression vector carrying a ribozyme sequence that targeted the GUC sequence in codon 18 of c-fms mRNA. It was introduced into TYK-nu cells that expressed M-CSF and its receptor. Its transfectant showed a reduced growth potential. The expression levels of c-fms protein and mRNA in the transfectant were clearly decreased with the expression of ribozyme RNA compared with that of an untransfected control or a transfectant with the vector without the ribozyme sequence. These results suggest that the ribozyme against GUC in codon 18 of c-fms mRNA is a promising tool for blocking the autocrine loop of M-CSF in ovarian epithelial carcinoma. Images Figure 2 Figure 3 Figure 5 Figure 6 PMID:9376277

Elevated levels of insulin-like growth factor (IGF)-I in serum rescue the severe growth retardation of IGF-I null mice.

PubMed

Wu, Yingjie; Sun, Hui; Yakar, Shoshana; LeRoith, Derek

2009-09-01

IGF-I plays a vital role in growth and development and acts in an endocrine and an autocrine/paracrine fashion. The purpose of the current study was to clarify whether elevated levels of IGF-I in serum can rescue the severe growth retardation and organ development and function of igf-I null mice. To address that, we overexpressed a rat igf-I transgene specifically in the liver of igf-I null mice. We found that in the total absence of tissue IGF-I, elevated levels of IGF-I in serum can support normal body size at puberty and after puberty but are insufficient to fully support the female reproductive system (evident by irregular estrous cycle, impaired development of ovarian corpus luteum, reduced number of uterine glands and endometrial hypoplasia, all leading to decreased number of pregnancies and litter size). We conclude that most autocrine/paracrine actions of IGF-I that determine organ growth and function can be compensated by elevated levels of endocrine IGF-I. However, in mice, full compensatory responses are evident later in development, suggesting that autocrine/paracrine IGF-I is critical for neonatal development. Furthermore, we show that tissue IGF-I is necessary for the development of the female reproductive system and cannot be compensated by elevated levels of serum IGF-I.

Small cell lung cancer growth is inhibited by miR-342 through its effect of the target gene IA-2.

PubMed

Xu, Huanyu; Cai, Tao; Carmona, Gilberto N; Abuhatzira, Liron; Notkins, Abner L

2016-09-26

Small cell lung cancers (SCLC) are tumors of neuroendocrine origin. Previous in vitro studies from our laboratory showed that SCLC expresses high levels of the transmembrane dense core vesicle protein IA-2 (islet cell antigen-2) as compared to normal lung cells. IA-2, through its effect on dense core vesicles (DCVs), is known to be involved in the secretion of hormones and neurotransmitters. It is believed that the dysregulated release of the neurotransmitter Acetylcholine (ACh) by DCVs has an autocrine effect on SCLC cell growth. Recently, we found that IA-2 is a target of the microRNA miR-342 and that miR-342 mimics suppress the expression of IA-2. The present experiments were initiated to see whether IA-2 and/or miR-342 affect the growth of SCLC. SCLC cell growth was evaluated following the knockdown of endogenous IA-2 with RNAi or by overexpressing miR-342 with a mimic. The secretion and content of ACh in SCLC cells was analyzed using a human acetylcholine ELISA (enzyme-linked immunosorbent assay) kit. The knockdown of endogenous IA-2 by RNAi reduced SCLC cell growth within 4 days by 40 % or more. Similar results were obtained when these cell lines were transfected with a miR-342 mimic. The knockdown of IA-2 by RNAi or miR-342 with a mimic also resulted in a significant decrease in the secretion of ACh, one of the autocrine hormones secreted by SCLC. Further studies revealed that the growth of SCLC cell lines that had been treated with the miR-342 mimic was restored to nearly normal levels by treatment with ACh. Our studies show for the first time that both miR-342 and its target gene IA-2 are involved in the growth process of SCLC cells and act by their effect on autocrine secretion. These findings point to possible new therapeutic approaches for the treatment of autocrine-induced tumor proliferation.

Asbestos and erionite prime and activate the NLRP3 inflammasome that stimulates autocrine cytokine release in human mesothelial cells

PubMed Central

2013-01-01

Background Pleural fibrosis and malignant mesotheliomas (MM) occur after exposures to pathogenic fibers, yet the mechanisms initiating these diseases are unclear. Results We document priming and activation of the NLRP3 inflammasome in human mesothelial cells by asbestos and erionite that is causally related to release of IL-1β, IL-6, IL-8, and Vascular Endothelial Growth Factor (VEGF). Transcription and release of these proteins are inhibited in vitro using Anakinra, an IL-1 receptor antagonist that reduces these cytokines in a human peritoneal MM mouse xenograft model. Conclusions These novel data show that asbestos-induced priming and activation of the NLRP3 inflammasome triggers an autocrine feedback loop modulated via the IL-1 receptor in mesothelial cell type targeted in pleural infection, fibrosis, and carcinogenesis. PMID:23937860

Kinetics of biochemical sensing by single cells and populations of cells

NASA Astrophysics Data System (ADS)

Saakian, David B.

2017-10-01

We investigate the collective stationary sensing using N communicative cells, which involves surface receptors, diffusive signaling molecules, and cell-cell communication messengers. We restrict the scenarios to the signal-to-noise ratios (SNRs) for both strong communication and extrinsic noise only. We modified a previous model [Bialek and Setayeshgar, Proc. Natl. Acad. Sci. USA 102, 10040 (2005), 10.1073/pnas.0504321102] to eliminate the singularities in the fluctuation correlations by considering a uniform receptor distribution over the surface of each cell with a finite radius a . The modified model enables a simple and rigorous mathematical treatment of the collective sensing phenomenon. We then derive the scaling of the SNR for both juxtacrine and autocrine cases in all dimensions. For the optimal locations of the cells in the autocrine case, we find identical scaling for both two and three dimensions.

Induction of autocrine factor inhibiting cell motility from murine B16-BL6 melanoma cells by alpha-melanocyte stimulating hormone.

PubMed

Murata, J; Ayukawa, K; Ogasawara, M; Watanabe, H; Saiki, I

1999-03-15

We have previously reported that neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) successfully inhibited Matrigel invasion and haptotactic migration of B16-BL6 melanoma cells towards both fibronectin and laminin without affecting their growth. In the present study, we investigated the inhibitory mechanism of tumor cell motility by alpha-MSH. Alpha-MSH significantly blocked the autocrine motility factor (AMF)-enhanced cell motility. However, alpha-MSH did neither prevent the secretion of AMF from B16-BL6 cells nor alter the expression level of AMF receptor (gp78). On the other hand, alpha-MSH induced the secretion of the motility inhibitory factor(s) from B16-BL6 cells in a concentration- and time-dependent manner. The induction of the motility inhibitor(s) was proportional to increasing levels of intracellular cAMP induced by alpha-MSH as well as forskolin, and the activity was abolished by an adenylate cyclase inhibitor, 2',5'-dideoxyadenosine (DDA). The motility-inhibiting activity in conditioned medium (CM) from alpha-MSH-treated B16-BL6 cells was found to have a m.w. below 3 kDa after fractionation. This activity was abolished by boiling but insensitive to trypsin. The treatment of tumor cells with cycloheximide reduced the activity in alpha-MSH-stimulated CM. Our results suggest that alpha-MSH inhibited the motility of B16-BL6 cells through induction of autocrine factor(s).

The heparin-binding domain of HB-EGF mediates localization to sites of cell-cell contact and prevents HB-EGF proteolytic release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prince, Robin N.; Schreiter, Eric R.; Zou, Peng

2010-07-01

Heparin-binding EGF-like growth factor (HB-EGF) is a ligand for EGF receptor (EGFR) and possesses the ability to signal in juxtacrine, autocrine and/or paracrine mode, with these alternatives being governed by the degree of proteolytic release of the ligand. Although the spatial range of diffusion of released HB-EGF is restricted by binding heparan-sulfate proteoglycans (HSPGs) in the extracellular matrix and/or cellular glycocalyx, ascertaining mechanisms governing non-released HB-EGF localization is also important for understanding its effects. We have employed a new method for independently tracking the localization of the extracellular EGFlike domain of HB-EGF and the cytoplasmic C-terminus. A striking observation wasmore » the absence of the HB-EGF transmembrane proform from the leading edge of COS-7 cells in a wound-closure assay; instead, this protein localized in regions of cell-cell contact. A battery of detailed experiments found that this localization derives from a trans interaction between extracellular HSPGs and the HBEGF heparin-binding domain, and that disruption of this interaction leads to increased release of soluble ligand and a switch in cell phenotype from juxtacrine-induced growth inhibition to autocrine-induced proliferation. Our results indicate that extracellular HSPGs serve to sequester the transmembrane pro-form of HB-EGF at the point of cell-cell contact, and that this plays a role in governing the balance between juxtacrine versus autocrine and paracrine signaling.« less

Negative feedback regulation of human platelets via autocrine activation of the platelet-derived growth factor alpha-receptor.

PubMed

Vassbotn, F S; Havnen, O K; Heldin, C H; Holmsen, H

1994-05-13

Human platelets contain platelet-derived growth factor (PDGF) in their alpha-granules which is released during platelet exocytosis. We show by immunoprecipitation and 125I-PDGF binding experiments that human platelets have functionally active PDGF alpha-receptors, but not beta-receptors. The PDGF alpha-receptor (PDGFR-alpha) was identified as a 170-kDa glycosylated protein-tyrosine kinase as found in other cell types. Stimulation of platelets with 0.1 unit/ml thrombin resulted in a significant increase (2-5-fold) of the tyrosine phosphorylation of the PDGFR-alpha, as determined by immunoprecipitation with phosphotyrosine antiserum as well as with PDGFR-alpha antiserum. The observed thrombin-induced autophosphorylation of the PDGFR-alpha was inhibited by the addition of a neutralizing monoclonal PDGF antibody. Thus, our results suggest that the platelet PDGFR-alpha is stimulated in an autocrine manner by PDGF secreted during platelet activation. Preincubation of platelets with PDGF inhibited thrombin-induced platelet aggregation and secretion of ATP + ADP and beta-hexosaminidase. Thrombin-induced platelet aggregation was also reversed when PDGF was added 30 s after thrombin stimulation. Inhibition of the autocrine PDGF pathway during platelet activation by the PDGF antibody led to a potentiation of thrombin-induced beta-hexosaminidase secretion. Thus, the PDGFR-alpha takes part in a negative feedback regulation during platelet activation. Our demonstration of PDGF alpha-receptors on human platelets and its inhibitory function during platelet activation identifies a new possible role of PDGF in the regulation of thrombosis.

Novel biomarkers in acute heart failure: MR-pro-adrenomedullin.

PubMed

Peacock, W Frank

2014-10-01

First isolated from human pheochromocytoma cells, adrenomedullin (ADM) is a peptide hormone with natriuretic, vasodilatory, and hypotensive effects mediated by cyclic adenosine monophosphate (cAMP), nitric oxide, and renal prostaglandin systems. ADM expression occurs in many tissues and organ systems, including cardiovascular, renal, pulmonary, cerebrovascular, gastrointestinal, and endocrine tissues where it acts as a circulating hormone and a local autocrine and paracrine hormone. ADM plasma concentrations are increased in hypertension, chronic renal disease, and heart failure. As ADM is unstable in vitro, it is necessary to measure its mid-regional pro-hormone fragment, the levels of which correspond to ADM concentration (MR-proADM). The prognostic potential of MR-proADM was recently demonstrated in the Biomarkers in Acute Heart Failure (BACH) trial. In this trial of 568 acute heart failure patients, MR-proADM was superior to both brain natriuretic peptide (BNP) and NT-proBNP in predicting mortality within 14 days. MR-proADM also provided significant additive incremental predictive value for 90-day mortality when added to BNP and NT-proBNP.

Nongenomic Glucocorticoid Suppression of a Postsynaptic Potassium Current via Emergent Autocrine Endocannabinoid Signaling in Hypothalamic Neuroendocrine Cells following Chronic Dehydration

PubMed Central

Wu, Ning

2017-01-01

Glucocorticoids rapidly stimulate endocannabinoid synthesis and modulation of synaptic transmission in hypothalamic neuroendocrine cells via a nongenomic signaling mechanism. The endocannabinoid actions are synapse-constrained by astrocyte restriction of extracellular spatial domains. Exogenous cannabinoids have been shown to modulate postsynaptic potassium currents, including the A-type potassium current (IA), in different cell types. The activity of magnocellular neuroendocrine cells is shaped by a prominent IA. We tested for a rapid glucocorticoid modulation of the postsynaptic IK and IA in magnocellular neuroendocrine cells of the hypothalamic paraventricular nucleus (PVN) using whole-cell recordings in rat brain slices. Application of the synthetic glucocorticoid dexamethasone (Dex) had no rapid effect on the IK or IA amplitude, voltage dependence, or kinetics in magnocellular neurons in slices from untreated rats. In magnocellular neurons from salt-loaded rats, however, Dex application caused a rapid suppression of the IA and a depolarizing shift in IA voltage dependence. Exogenously applied endocannabinoids mimicked the rapid Dex modulation of the IA, and CB1 receptor antagonists and agonists blocked and occluded the Dex-induced changes in the IA, respectively, suggesting an endocannabinoid dependence of the rapid glucocorticoid effect. Preincubation of control slices in a gliotoxin resulted in the partial recapitulation of the glucocorticoid-induced rapid suppression of the IA. These findings demonstrate a glucocorticoid suppression of the postsynaptic IA in PVN magnocellular neurons via an autocrine endocannabinoid-dependent mechanism following chronic dehydration, and suggest a possible role for astrocytes in the control of the autocrine endocannabinoid actions. PMID:28966975

DOE Office of Scientific and Technical Information (OSTI.GOV)

Che, Qi; Liu, Bin-Ya; Wang, Fang-Yuan

Highlights: • IL-6 could promote endometrial cancer cells proliferation. • IL-6 promotes its own production through an autocrine feedback loop. • ERK and NF-κB pathway inhibitors inhibit IL-6 production and tumor growth. • IL-6 secretion relies on the activation of ERK–NF-κB pathway axis. • An orthotopic nude endometrial carcinoma model confirms the effect of IL-6. - Abstract: Interleukin (IL)-6 as an inflammation factor, has been proved to promote cancer proliferation in several human cancers. However, its role in endometrial cancer has not been studied clearly. Previously, we demonstrated that IL-6 promoted endometrial cancer progression through local estrogen biosynthesis. In thismore » study, we proved that IL-6 could directly stimulate endometrial cancer cells proliferation and an autocrine feedback loop increased its production even after the withdrawal of IL-6 from the medium. Next, we analyzed the mechanism underlying IL-6 production in the feedback loop and found that its production and IL-6-stimulated cell proliferation were effectively blocked by pharmacologic inhibitors of nuclear factor-kappa B (NF-κB) and extra-cellular signal-regulated kinase (ERK). Importantly, activation of ERK was upstream of the NF-κB pathways, revealing the hierarchy of this event. Finally, we used an orthotopic nude endometrial carcinoma model to confirm the effects of IL-6 on the tumor progression. Taken together, these data indicate that IL-6 promotes endometrial carcinoma growth through an expanded autocrine regulatory loop and implicate the ERK–NF-κB pathway as a critical mediator of IL-6 production, implying IL-6 to be an important therapeutic target in endometrial carcinoma.« less

Fibroblast growth factor receptor 4 (FGFR4) and fibroblast growth factor 19 (FGF19) autocrine enhance breast cancer cells survival.

PubMed

Tiong, Kai Hung; Tan, Boon Shing; Choo, Heng Lungh; Chung, Felicia Fei-Lei; Hii, Ling-Wei; Tan, Si Hoey; Khor, Nelson Tze Woei; Wong, Shew Fung; See, Sze-Jia; Tan, Yuen-Fen; Rosli, Rozita; Cheong, Soon-Keng; Leong, Chee-Onn

2016-09-06

Basal-like breast cancer is an aggressive tumor subtype with poor prognosis. The discovery of underlying mechanisms mediating tumor cell survival, and the development of novel agents to target these pathways, is a priority for patients with basal-like breast cancer. From a functional screen to identify key drivers of basal-like breast cancer cell growth, we identified fibroblast growth factor receptor 4 (FGFR4) as a potential mediator of cell survival. We found that FGFR4 mediates cancer cell survival predominantly via activation of PI3K/AKT. Importantly, a subset of basal-like breast cancer cells also secrete fibroblast growth factor 19 (FGF19), a canonical ligand specific for FGFR4. siRNA-mediated silencing of FGF19 or neutralization of extracellular FGF19 by anti-FGF19 antibody (1A6) decreases AKT phosphorylation, suppresses cancer cell growth and enhances doxorubicin sensitivity only in the FGFR4+/FGF19+ breast cancer cells. Consistently, FGFR4/FGF19 co-expression was also observed in 82 out of 287 (28.6%) primary breast tumors, and their expression is strongly associated with AKT phosphorylation, Ki-67 staining, higher tumor stage and basal-like phenotype. In summary, our results demonstrated the presence of an FGFR4/FGF19 autocrine signaling that mediates the survival of a subset of basal-like breast cancer cells and suggest that inactivation of this autocrine loop may potentially serve as a novel therapeutic intervention for future treatment of breast cancers.

Stem cell autocrine CXCL12/CXCR4 stimulates invasion and metastasis of esophageal cancer.

PubMed

Wang, Xingwei; Cao, Yan; Zhang, Shirong; Chen, Zhihui; Fan, Ling; Shen, Xiaochun; Zhou, Shiwen; Chen, Dongfeng

2017-05-30

Esophageal cancer is one of the most common malignant tumors of the digestive tract. The greatest obstacle to the curing of esophageal cancer is its propensity to spread and metastasize. Esophageal cancer stem cells are considered the source for recurrence and metastasis of the tumors. While clinical evidence suggested that continuous up-regulation of CXCL12/CXCR4 was significantly associated with poor prognosis in patients with esophageal cancer, but the role and mechanism of CXCL12/CXCR4 in the invasion and metastasis of esophageal cancer has not been reported by far. This study found that esophageal cancer stem cells not only autocrine a great amount of CXCL12, but also high expression of its corresponding receptor CXCR4. Most importantly, the ability of esophageal cancer stem cells to spread and metastasize could be inhibited by blockage of CXCR4 with inhibitors or shRNA approaches both in vivo and in vitro studies. The important role of CXCL12 in the invasion and metastasis of esophageal cancer stem cells was also confirmed by loss-of-function and gain-of-function strategies. Mechanistically, we demonstrated that CXCL12/CXCR4 activated the ERK1/2 pathway and thereby ultimately maintained the characteristics of high-level invasion and metastasis of esophageal cancer stem cells. Taken together, our findings suggested that autocrine CXCL12/CXCR4 was one of the major mechanisms underlying the metastatic property of esophageal cancer stem cells through ERK1/2 signaling pathway, and might serve as a therapeutic target for esophageal cancer patients.

Autocrine IL-10 functions as a rheostat for M1 macrophage glycolytic commitment by tuning nitric oxide production.

PubMed

Baseler, Walter A; Davies, Luke C; Quigley, Laura; Ridnour, Lisa A; Weiss, Jonathan M; Hussain, S Perwez; Wink, David A; McVicar, Daniel W

2016-12-01

Inflammatory maturation of M1 macrophages by proinflammatory stimuli such as toll like receptor ligands results in profound metabolic reprogramming resulting in commitment to aerobic glycolysis as evidenced by repression of mitochondrial oxidative phosphorylation (OXPHOS) and enhanced glucose utilization. In contrast, "alternatively activated" macrophages adopt a metabolic program dominated by fatty acid-fueled OXPHOS. Despite the known importance of these developmental stages on the qualitative aspects of an inflammatory response, relatively little is know regarding the regulation of these metabolic adjustments. Here we provide evidence that the immunosuppressive cytokine IL-10 defines a metabolic regulatory loop. Our data show for the first time that lipopolysaccharide (LPS)-induced glycolytic flux controls IL-10-production via regulation of mammalian target of rapamycin (mTOR) and that autocrine IL-10 in turn regulates macrophage nitric oxide (NO) production. Genetic and pharmacological manipulation of IL-10 and nitric oxide (NO) establish that metabolically regulated autocrine IL-10 controls glycolytic commitment by limiting NO-mediated suppression of OXPHOS. Together these data support a model where autocine IL-10 production is controlled by glycolytic flux in turn regulating glycolytic commitment by preserving OXPHOS via suppression of NO. We propose that this IL-10-driven metabolic rheostat maintains metabolic equilibrium during M1 macrophage differentiation and that perturbation of this regulatory loop, either directly by exogenous cellular sources of IL-10 or indirectly via limitations in glucose availability, skews the cellular metabolic program altering the balance between inflammatory and immunosuppressive phenotypes. Copyright © 2016. Published by Elsevier B.V.

VEGF elicits epithelial-mesenchymal transition (EMT) in prostate intraepithelial neoplasia (PIN)-like cells via an autocrine loop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonzalez-Moreno, Oscar; Lecanda, Jon; Green, Jeffrey E.

2010-02-15

Vascular endothelial growth factor (VEGF) is overexpressed during the transition from prostate intraepithelial neoplasia (PIN) to invasive carcinoma. We have mimicked such a process in vitro using the PIN-like C3(1)/Tag-derived Pr-111 cell line, which expresses low levels of VEGF and exhibits very low tumorigenicity in vivo. Elevated expression of VEGF164 in Pr-111 cells led to a significant increase in tumorigenicity, invasiveness, proliferation rates and angiogenesis. Moreover, VEGF164 induced strong changes in cell morphology and cell transcriptome through an autocrine mechanism, with changes in TGF-beta1- and cytoskeleton-related pathways, among others. Further analysis of VEGF-overexpressing Pr-111 cells or following exogenous addition ofmore » recombinant VEGF shows acquisition of epithelial-mesenchymal transition (EMT) features, with an increased expression of mesenchymal markers, such as N-cadherin, Snail1, Snail2 (Slug) and vimentin, and a decrease in E-cadherin. Administration of VEGF led to changes in TGF-beta1 signaling, including reduction of Smad7 (TGF-beta inhibitory Smad), increase in TGF-betaR-II, and translocation of phospho-Smad3 to the nucleus. Our results suggest that increased expression of VEGF in malignant cells during the transition from PIN to invasive carcinoma leads to EMT through an autocrine loop, which would promote tumor cell invasion and motility. Therapeutic blockade of VEGF/TGF-beta1 in PIN lesions might impair not only tumor angiogenesis, but also the early dissemination of malignant cells outside the epithelial layer.« less

Quantitative Analysis of Human Pluripotency and Neural Specification by In-Depth (Phospho)Proteomic Profiling.

PubMed

Singec, Ilyas; Crain, Andrew M; Hou, Junjie; Tobe, Brian T D; Talantova, Maria; Winquist, Alicia A; Doctor, Kutbuddin S; Choy, Jennifer; Huang, Xiayu; La Monaca, Esther; Horn, David M; Wolf, Dieter A; Lipton, Stuart A; Gutierrez, Gustavo J; Brill, Laurence M; Snyder, Evan Y

2016-09-13

Controlled differentiation of human embryonic stem cells (hESCs) can be utilized for precise analysis of cell type identities during early development. We established a highly efficient neural induction strategy and an improved analytical platform, and determined proteomic and phosphoproteomic profiles of hESCs and their specified multipotent neural stem cell derivatives (hNSCs). This quantitative dataset (nearly 13,000 proteins and 60,000 phosphorylation sites) provides unique molecular insights into pluripotency and neural lineage entry. Systems-level comparative analysis of proteins (e.g., transcription factors, epigenetic regulators, kinase families), phosphorylation sites, and numerous biological pathways allowed the identification of distinct signatures in pluripotent and multipotent cells. Furthermore, as predicted by the dataset, we functionally validated an autocrine/paracrine mechanism by demonstrating that the secreted protein midkine is a regulator of neural specification. This resource is freely available to the scientific community, including a searchable website, PluriProt. Published by Elsevier Inc.

Pluripotency Gene Expression and Growth Control in Cultures of Peripheral Blood Monocytes during Their Conversion into Programmable Cells of Monocytic Origin (PCMO): Evidence for a Regulatory Role of Autocrine Activin and TGF-β

PubMed Central

Ungefroren, Hendrik; Hyder, Ayman; Hinz, Hebke; Groth, Stephanie; Lange, Hans; El-Sayed, Karim M. Fawzy; Ehnert, Sabrina; Nüssler, Andreas K.; Fändrich, Fred; Gieseler, Frank

2015-01-01

Previous studies have shown that peripheral blood monocytes can be converted in vitro to a stem cell-like cell termed PCMO as evidenced by the re-expression of pluripotency-associated genes, transient proliferation, and the ability to adopt the phenotype of hepatocytes and insulin-producing cells upon tissue-specific differentiation. However, the regulatory interactions between cultured cells governing pluripotency and mitotic activity have remained elusive. Here we asked whether activin(s) and TGF-β(s), are involved in PCMO generation. De novo proliferation of PCMO was higher under adherent vs. suspended culture conditions as revealed by the appearance of a subset of Ki67-positive monocytes and correlated with down-regulation of p21WAF1 beyond day 2 of culture. Realtime-PCR analysis showed that PCMO express ActRIIA, ALK4, TβRII, ALK5 as well as TGF-β1 and the βA subunit of activin. Interestingly, expression of ActRIIA and ALK4, and activin A levels in the culture supernatants increased until day 4 of culture, while levels of total and active TGF-β1 strongly declined. PCMO responded to both growth factors in an autocrine fashion with intracellular signaling as evidenced by a rise in the levels of phospho-Smad2 and a drop in those of phospho-Smad3. Stimulation of PCMO with recombinant activins (A, B, AB) and TGF-β1 induced phosphorylation of Smad2 but not Smad3. Inhibition of autocrine activin signaling by either SB431542 or follistatin reduced both Smad2 activation and Oct4A/Nanog upregulation. Inhibition of autocrine TGF-β signaling by either SB431542 or anti-TGF-β antibody reduced Smad3 activation and strongly increased the number of Ki67-positive cells. Furthermore, anti-TGF-β antibody moderately enhanced Oct4A/Nanog expression. Our data show that during PCMO generation pluripotency marker expression is controlled positively by activin/Smad2 and negatively by TGF-β/Smad3 signaling, while relief from growth inhibition is primarily the result of reduced TGF-β/Smad3, and to a lesser extent, activin/Smad2 signaling. PMID:25707005

Annexin A2 and its downstream IL-6 and HB-EGF as secretory biomarkers in the differential diagnosis of Her-2 negative breast cancer.

PubMed

Shetty, Praveenkumar; Patil, Vidya S; Mohan, Rajashekar; D'souza, Leonard Clinton; Bargale, Anil; Patil, Basavaraj R; Dinesh, U S; Haridas, Vikram; Kulkarni, Shrirang P

2017-07-01

Background AnnexinA2 (AnxA2) membrane deposition has a critical role in HB-EGF shedding as well as IL-6 secretion in breast cancer cells. This autocrine cycle has a major role in cancer cell proliferation, migration and metastasis. The objective of the study is to demonstrate annexinA2-mediated autocrine regulation via HB-EGF and IL-6 in Her-2 negative breast cancer progression. Methods Secretory annexinA2, HB-EGF and IL-6 were analysed in the peripheral blood sample of Her-2 negative ( n = 20) and positive breast cancer patients ( n = 16). Simultaneously, tissue expression was analysed by immunohistochemistry. The membrane deposition of these secretory ligands and their autocrine regulation was demonstrated using triple-negative breast cancer cell line model. Results Annexina2 and HB-EGF expression are inversely correlated with Her-2, whereas IL-6 expression is seen in both Her-2 negative and positive breast cancer cells. RNA interference studies and upregulation of annexinA2 proved that annexinA2 is the upstream of this autocrine pathway. Abundant soluble serum annexinA2 is secreted in Her-2 negative breast cancer (359.28 ± 63.73 ng/mL) compared with normal (286.10 ± 70.04 ng/mL, P < 0.01) and Her-2 positive cases (217.75 ± 60.59 ng/mL, P < 0.0001). In Her-2 negative cases, the HB-EGF concentrations (179.16 ± 118.81 pg/mL) were highly significant compared with normal (14.92 ± 17.33 pg/mL, P < 0.001). IL-6 concentrations were increased significantly in both the breast cancer phenotypes as compared with normal ( P < 0.001). Conclusion The specific expression pattern of annexinA2 and HB-EGF in triple-negative breast cancer tissues, increased secretion compared with normal cells, and their major role in the regulation of EGFR downstream signalling makes these molecules as a potential tissue and serum biomarker and an excellent therapeutic target in Her-2 negative breast cancer.

Membrane-To-Nucleus Signaling Links Insulin-Like Growth Factor-1- and Stem Cell Factor-Activated Pathways

PubMed Central

Hayashi, Yujiro; Asuzu, David T.; Gibbons, Simon J.; Aarsvold, Kirsten H.; Bardsley, Michael R.; Lomberk, Gwen A.; Mathison, Angela J.; Kendrick, Michael L.; Shen, K. Robert; Taguchi, Takahiro; Gupta, Anu; Rubin, Brian P.; Fletcher, Jonathan A.; Farrugia, Gianrico; Urrutia, Raul A.; Ordog, Tamas

2013-01-01

Stem cell factor (mouse: Kitl, human: KITLG) and insulin-like growth factor-1 (IGF1), acting via KIT and IGF1 receptor (IGF1R), respectively, are critical for the development and integrity of several tissues. Autocrine/paracrine KITLG-KIT and IGF1-IGF1R signaling are also activated in several cancers including gastrointestinal stromal tumors (GIST), the most common sarcoma. In murine gastric muscles, IGF1 promotes Kitl-dependent development of interstitial cells of Cajal (ICC), the non-neoplastic counterpart of GIST, suggesting cooperation between these pathways. Here, we report a novel mechanism linking IGF1-IGF1R and KITLG-KIT signaling in both normal and neoplastic cells. In murine gastric muscles, the microenvironment for ICC and GIST, human hepatic stellate cells (LX-2), a model for cancer niches, and GIST cells, IGF1 stimulated Kitl/KITLG protein and mRNA expression and promoter activity by activating several signaling pathways including AKT-mediated glycogen synthase kinase-3β inhibition (GSK3i). GSK3i alone also stimulated Kitl/KITLG expression without activating mitogenic pathways. Both IGF1 and GSK3i induced chromatin-level changes favoring transcriptional activation at the Kitl promoter including increased histone H3/H4 acetylation and H3 lysine (K) 4 methylation, reduced H3K9 and H3K27 methylation and reduced occupancy by the H3K27 methyltransferase EZH2. By pharmacological or RNA interference-mediated inhibition of chromatin modifiers we demonstrated that these changes have the predicted impact on KITLG expression. KITLG knock-down and immunoneutralization inhibited the proliferation of GIST cells expressing wild-type KIT, signifying oncogenic autocrine/paracrine KITLG-KIT signaling. We conclude that membrane-to-nucleus signaling involving GSK3i establishes a previously unrecognized link between the IGF1-IGF1R and KITLG-KIT pathways, which is active in both physiologic and oncogenic contexts and can be exploited for therapeutic purposes. PMID:24116170

Autocrine motility factor (neuroleukin, phosphohexose isomerase) induces cell movement through 12-lipoxygenase-dependent tyrosine phosphorylation and serine dephosphorylation events.

PubMed

Timár, J; Tóth, S; Tóvári, J; Paku, S; Raz, A

1999-01-01

Autocrine motility factor (AMF) is one of the motility cytokines regulating tumor cell migration, therefore identification of the signaling pathway coupled with it has critical importance. Previous studies revealed several elements of this pathway predominated by lipoxygenase-PKC activations but the role for tyrosine kinases remained questionable. Motility cytokines frequently have mitogenic effect as well, producing activation of overlapping signaling pathways therefore we have used B16a melanoma cells as models where AMF has exclusive motility effect. Our studies revealed that in B16a cells AMF initiated rapid (1-5 min) activation of the protein tyrosine kinase (PTK) cascade inducing phosphorylation of 179, 125, 95 and 40/37 kD proteins which was mediated by upstream cyclo- and lipoxygenases. The phosphorylated proteins were localized to the cortical actin-stress fiber attachment zones in situ by confocal microscopy. On the other hand, AMF receptor activation induced significant decrease in overall serine-phosphorylation level of cellular proteins accompanied by serine phosphorylation of 200, 90, 78 and 65 kd proteins. The decrease in serine phosphorylation was independent of PTKs, PKC as well as cyclo- and lipoxygenases. However, AMF induced robust translocation of PKCalpha to the stress fibers and cortical actin suggesting a critical role for this kinase in the generation of the motility signal. Based on the significant decrease in serine phosphorylation after AMF stimulus in B16a cells we postulated the involvement of putative serine/threonine phosphatase(s) upstream lipoxygenase and activation of the protein tyrosine kinase cascade downstream cyclo- and lipoxygenase(s) in the previously identified autocrine motility signal.

Collagen and Stretch Modulate Autocrine Secretion of Insulin-like Growth Factor-1 and Insulin-like Growth Factor Binding Proteins from Differentiated Skeletal Muscle Cells

NASA Technical Reports Server (NTRS)

Perrone, Carmen E.; Fenwick-Smith, Daniela; Vandenburgh, Herman H.

1995-01-01

Stretch-induced skeletal muscle growth may involve increased autocrine secretion of insulin-like growth factor-1 (IGF-1) since IGF-1 is a potent growth factor for skeletal muscle hypertrophy, and stretch elevates IGF-1 mRNA levels in vivo. In tissue cultures of differentiated avian pectoralis skeletal muscle cells, nanomolar concentrations of exogenous IGF-1 stimulated growth in mechanically stretched but not static cultures. These cultures released up to 100 pg of endogenously produced IGF-1/micro-g of protein/day, as well as three major IGF binding proteins of 31, 36, and 43 kilodaltons (kDa). IGF-1 was secreted from both myofibers and fibroblasts coexisting in the muscle cultures. Repetitive stretch/relaxation of the differentiated skeletal muscle cells stimulated the acute release of IGF-1 during the first 4 h after initiating mechanical activity, but caused no increase in the long-term secretion over 24-72 h of IGF-1, or its binding proteins. Varying the intensity and frequency of stretch had no effect on the long-term efflux of IGF-1. In contrast to stretch, embedding the differentiated muscle cells in a three-dimensional collagen (Type I) matrix resulted in a 2-5-fold increase in long-term IGF-1 efflux over 24-72 h. Collagen also caused a 2-5-fold increase in the release of the IGF binding proteins. Thus, both the extracellular matrix protein type I collagen and stretch stimulate the autocrine secretion of IGF-1, but with different time kinetics. This endogenously produced growth factor may be important for the growth response of skeletal myofibers to both types of external stimuli.

Dehydration-induced modulation of κ-opioid inhibition of vasopressin neurone activity

PubMed Central

Scott, Victoria; Bishop, Valerie R; Leng, Gareth; Brown, Colin H

2009-01-01

Dehydration increases vasopressin (antidiuretic hormone) secretion from the posterior pituitary gland to reduce water loss in the urine. Vasopressin secretion is determined by action potential firing in vasopressin neurones, which can exhibit continuous, phasic (alternating periods of activity and silence), or irregular activity. Autocrine κ-opioid inhibition contributes to the generation of activity patterning of vasopressin neurones under basal conditions and so we used in vivo extracellular single unit recording to test the hypothesis that changes in autocrine κ-opioid inhibition drive changes in activity patterning of vasopressin neurones during dehydration. Dehydration increased the firing rate of rat vasopressin neurones displaying continuous activity (from 7.1 ± 0.5 to 9.0 ± 0.6 spikes s−1) and phasic activity (from 4.2 ± 0.7 to 7.8 ± 0.9 spikes s−1), but not those displaying irregular activity. The dehydration-induced increase in phasic activity was via an increase in intraburst firing rate. The selective κ-opioid receptor antagonist nor-binaltorphimine increased the firing rate of phasic neurones in non-dehydrated rats (from 3.4 ± 0.8 to 5.3 ± 0.6 spikes s−1) and dehydrated rats (from 6.4 ± 0.5 to 9.1 ± 1.2 spikes s−1), indicating that κ-opioid feedback inhibition of phasic bursts is maintained during dehydration. In a separate series of experiments, prodynorphin mRNA expression was increased in vasopressin neurones of hyperosmotic rats, compared to hypo-osmotic rats. Hence, it appears that dynorphin expression in vasopressin neurones undergoes dynamic changes in proportion to the required secretion of vasopressin so that, even under stimulated conditions, autocrine feedback inhibition of vasopressin neurones prevents over-excitation. PMID:19822541

Regulation of expression of hyperalgesic priming by estrogen receptor alpha in the rat

PubMed Central

Ferrari, Luiz F.; Araldi, Dionéia; Levine, Jon D.

2017-01-01

Hyperalgesic priming, a sexually dimorphic model of transition to chronic pain, is expressed as prolongation of prostaglandin E2 (PGE2)-induced hyperalgesia by the activation of an additional pathway including an autocrine mechanism at the plasma membrane. The autocrine mechanism involves the transport of cAMP to the extracellular space, and its conversion to AMP and adenosine, by ecto-5′phosphodiesterase and ecto-5′nucleotidase, respectively. The end product, adenosine, activates A1 receptors, producing delayed onset prolongation of PGE2 hyperalgesia. We tested the hypothesis that the previously reported, estrogen-dependent, sexual dimorphism observed in the induction of priming is present in the mechanisms involved in its expression, as a regulatory effect on ecto-5′nucleotidase by estrogen receptor alpha (EsRα), in female rats. In the primed paw AMP hyperalgesia was dependent on conversion to adenosine, being prevented by ecto-5′nucleotidase inhibitor AMPCP and A1 receptor antagonist DPCPX. To investigate an interaction between EsRα and ecto-5′nucleotidase, we treated primed female rats with ODN antisense or mismatch against EsRα mRNA. While in rats treated with antisense AMP-induced hyperalgesia was abolished, the A1 receptor agonist N6-cyclopentiladenosine (CPA) still produced hyperalgesia. Thus, EsRα interacts with this autocrine pathway at the level of ecto-5′nucleotidase. These results demonstrate a sexually dimorphic mechanism for the expression of priming. Perspective This study presents evidence of an estrogen-dependent mechanism of expression of chronic pain in females, supporting the suggestion that differential targets must be considered when establishing protocols for the treatment of painful conditions in males and females. PMID:28089711

Ccl5 establishes an autocrine high-grade glioma growth regulatory circuit critical for mesenchymal glioblastoma survival

PubMed Central

Pan, Yuan; Smithson, Laura J.; Ma, Yu; Hambardzumyan, Dolores; Gutmann, David H.

2017-01-01

Glioblastoma (GBM) is the most common malignant brain tumor in adults, with a median survival of 15 months. These poor clinical outcomes have prompted the development of drugs that block neoplastic cancer cell growth; however, non-neoplastic cell-derived signals (chemokines and cytokines) in the tumor microenvironment may also represent viable treatment targets. One such chemokine, Ccl5, produced by low-grade tumor-associated microglia, is responsible for maintaining neurofibromatosis type 1 (NF1) mouse optic glioma growth in vivo. Since malignant gliomas may achieve partial independence from growth regulatory factors produced by non-neoplastic cells in the tumor microenvironment by producing the same cytokines secreted by the stromal cells in their low-grade counterparts, we tested the hypothesis that CCL5/CCL5-receptor signaling in glioblastoma creates an autocrine circuit important for high-grade glioma growth. Herein, we demonstrate that increased CCL5 expression was restricted to both human and mouse mesenchymal GBM (M-GBM), a molecular subtype characterized by NF1 loss. We further show that the NF1 protein, neurofibromin, negatively regulates Ccl5 expression through suppression of AKT/mTOR signaling. Consistent with its role as a glioblastoma growth regulator, Ccl5 knockdown in M-GBM cells reduces M-GBM cell survival in vitro, and increases mouse glioblastoma survival in vivo. Finally, we demonstrate that Ccl5 operates through an unconventional CCL5 receptor, CD44, to inhibit M-GBM apoptosis. Collectively, these findings reveal an NF1-dependent CCL5-mediated pathway that regulates M-GBM cell survival, and support the concept that paracrine factors important for low-grade glioma growth can be usurped by high-grade tumors to create autocrine regulatory circuits that maintain malignant glioma survival. PMID:28380429

TGF-β1 stimulates movement of renal proximal tubular epithelial cells in a three-dimensional cell culture via an autocrine TGF-β2 production.

PubMed

Luo, Deyi; Guan, Qiunong; Wang, Kunjie; Nguan, Christopher Y C; Du, Caigan

2017-01-01

TGF-βs are multifunctional cytokines, but their roles in human renal homeostasis are not fully understood. This study investigated the role of TGF-β1 in the movement of human renal proximal tubular epithelial cells (PTECs) in a three-dimensional (3D) model. HKC-8 cells, a human PTEC line, were grown in a 3D collagen culture system. Cell movement was observed under a microscope. The gene expression was examined using PCR Arrays or qRT-PCR, and protein levels by Western blot. Here, we showed that the tight junction structure formed between adjacent cells of a HKC-8 cell colony in 3D cultures, and TGF-β1 stimulated their movement, evidenced by the appearance of fingerlike pseudopodia in the leader cells at the edge of the colonies. The cell movement of these human PTECs was correlated with up-regulation of both MMP2 and MMP9 and down-regulation or inactivation of PLAUR and PTK2B. Analysis of TGF-β signaling targets confirmed autocrine production of TGF-β2 and its cleaving enzyme furin as well as SNAI1 by TGF-β1stimulation. Knockdown of TGF-β2 expression disrupted TGF-β1-stimulated PTEC invasiveness, which was correlated with the down-regulation of MMP2 and MMP9. In conclusion, the activation of TGF-β receptor autocrine signaling by up-regulated TGF-β2 may play a pivotal role in TGF-β1-induced human PTEC movement, which could be mediated at least by both MMP2 and MMP9. Copyright © 2016 Elsevier Inc. All rights reserved.

The growth and aggressive behavior of human osteosarcoma is regulated by a CaMKII-controlled autocrine VEGF signaling mechanism.

PubMed

Daft, Paul G; Yang, Yang; Napierala, Dobrawa; Zayzafoon, Majd

2015-01-01

Osteosarcoma (OS) is a hyperproliferative malignant tumor that requires a high vascular density to maintain its large volume. Vascular Endothelial Growth Factor (VEGF) plays a crucial role in angiogenesis and acts as a paracrine and autocrine agent affecting both endothelial and tumor cells. The alpha-Ca2+/Calmodulin kinase two (α-CaMKII) protein is an important regulator of OS growth. Here, we investigate the role of α-CaMKII-induced VEGF in the growth and tumorigenicity of OS. We show that the pharmacologic and genetic inhibition of α-CaMKII results in decreases in VEGF gene expression (50%) and protein secretion (55%), while α- CaMKII overexpression increases VEGF gene expression (250%) and protein secretion (1,200%). We show that aggressive OS cells (143B) express high levels of VEGF receptor 2 (VEGFR-2) and respond to exogenous VEGF (100nm) by increasing intracellular calcium (30%). This response is ameliorated by the VEGFR inhibitor CBO-P11, suggesting that secreted VEGF results in autocrine stimulated α-CaMKII activation. Furthermore, we show that VEGF and α-CaMKII inhibition decreases the transactivation of the HIF-1α and AP-1 reporter constructs. Additionally, chromatin immunoprecipitation assay shows significantly decreased binding of HIF-1α and AP-1 to their responsive elements in the VEGF promoter. These data suggest that α-CaMKII regulates VEGF transcription by controlling HIF-1α and AP-1 transcriptional activities. Finally, CBO-P11, KN-93 (CaMKII inhibitor) and combination therapy significantly reduced tumor burden in vivo. Our results suggest that VEGF-induced OS tumor growth is controlled by CaMKII and dual therapy by CaMKII and VEGF inhibitors could be a promising therapy against this devastating adolescent disease.

The Growth and Aggressive Behavior of Human Osteosarcoma Is Regulated by a CaMKII-Controlled Autocrine VEGF Signaling Mechanism

PubMed Central

Daft, Paul G.; Yang, Yang; Napierala, Dobrawa; Zayzafoon, Majd

2015-01-01

Osteosarcoma (OS) is a hyperproliferative malignant tumor that requires a high vascular density to maintain its large volume. Vascular Endothelial Growth Factor (VEGF) plays a crucial role in angiogenesis and acts as a paracrine and autocrine agent affecting both endothelial and tumor cells. The alpha-Ca2+/Calmodulin kinase two (α-CaMKII) protein is an important regulator of OS growth. Here, we investigate the role of α-CaMKII-induced VEGF in the growth and tumorigenicity of OS. We show that the pharmacologic and genetic inhibition of α-CaMKII results in decreases in VEGF gene expression (50%) and protein secretion (55%), while α- CaMKII overexpression increases VEGF gene expression (250%) and protein secretion (1,200%). We show that aggressive OS cells (143B) express high levels of VEGF receptor 2 (VEGFR-2) and respond to exogenous VEGF (100nm) by increasing intracellular calcium (30%). This response is ameliorated by the VEGFR inhibitor CBO-P11, suggesting that secreted VEGF results in autocrine stimulated α-CaMKII activation. Furthermore, we show that VEGF and α-CaMKII inhibition decreases the transactivation of the HIF-1α and AP-1 reporter constructs. Additionally, chromatin immunoprecipitation assay shows significantly decreased binding of HIF-1α and AP-1 to their responsive elements in the VEGF promoter. These data suggest that α-CaMKII regulates VEGF transcription by controlling HIF-1α and AP-1 transcriptional activities. Finally, CBO-P11, KN-93 (CaMKII inhibitor) and combination therapy significantly reduced tumor burden in vivo. Our results suggest that VEGF-induced OS tumor growth is controlled by CaMKII and dual therapy by CaMKII and VEGF inhibitors could be a promising therapy against this devastating adolescent disease. PMID:25860662

Cholecystokinin (CCK) and CCK receptor expression by human gliomas: Evidence for an autocrine/paracrine stimulatory loop.

PubMed

Oikonomou, Eftychia; Buchfelder, Michael; Adams, Eric F

2008-06-01

Cholecystokinin (CCK) is a gut-brain peptide has been described to be able to induce mitosis according to recent studies. Additionally, conflicting data has been published on whether tumours of the central and peripheral nervous system in general, and gliomas in particular, express CCK receptors. In the present in vitro study we employed reverse transcription followed by the polymerase chain reaction (RT-PCR) to investigate whether mRNA for CCK-A and CCK-B receptors as well as CCK peptide itself is present in primary human gliomas and the U-87 MG GBM cell line. The data show that 14/14 (100%) of the primary gliomas exhibited mRNA expression for the CCK peptide gene and the B receptor including the U-87 MG cells, whereas, only 2/14 (14%) showed presence of the CCK-A receptor. The presence of CCK receptors together with CCK peptide expression itself suggests presence of an autocrine loop controlling glioma cell growth. In support of this conclusion, a neutralizing antibody against the CCK peptide exhibited a dose dependent inhibition of cell growth whereas, antagonists to CCK caused a dose depend inhibition of exogenous stimulated glioma cell growth in vitro, via the CCK-B receptor which is PKC activated. Assessment of apoptosis and proteasome activity were undertaken and we report that treatment with CCK antagonists decreased proteasome and increased caspase-3 activity. These data indicate that CCK peptide and CCK-B are abundant in human gliomas and they act to stimulate cell growth in an autocrine manner, primarily via the high affinity CCK-B receptor, which was blocked by antagonists to CCK, perhaps via apoptosis.

Type I Interferons Function as Autocrine and Paracrine Factors to Induce Autotaxin in Response to TLR Activation

PubMed Central

Song, Jianwen; Guan, Ming; Zhao, Zhenwen; Zhang, Junjie

2015-01-01

Lysophosphatidic acid (LPA) is an important phospholipid mediator in inflammation and immunity. However, the mechanism of LPA regulation during inflammatory response is largely unknown. Autotaxin (ATX) is the key enzyme to produce extracellular LPA from lysophosphatidylcholine (LPC). In this study, we found that ATX was induced in monocytic THP-1 cells by TLR4 ligand lipopolysaccharide (LPS), TLR9 ligand CpG oligonucleotide, and TLR3 ligand poly(I:C), respectively. The ATX induction by TLR ligand was abolished by the neutralizing antibody against IFN-β or the knockdown of IFNAR1, indicating that type I IFN autocrine loop is responsible for the ATX induction upon TLR activation. Both IFN-β and IFN-α were able to induce ATX expression via the JAK-STAT and PI3K-AKT pathways but with different time-dependent manners. The ATX induction by IFN-β was dramatically enhanced by IFN-γ, which had no significant effect on ATX expression alone, suggesting a synergy effect between type I and type II IFNs in ATX induction. Extracellular LPA levels were significantly increased when THP-1 cells were treated with IFN-α/β or TLR ligands. In addition, the type I IFN-mediated ATX induction was identified in human monocyte-derived dendritic cells (moDCs) stimulated with LPS or poly(I:C), and IFN-α/β could induce ATX expression in human peripheral blood mononuclear cells (PBMCs) and monocytes isolated form blood samples. These results suggest that, in response to TLR activation, ATX is induced through a type I INF autocrine-paracrine loop to enhance LPA generation. PMID:26313906

Autocrine inhibition of the c-fms proto-oncogene reduces breast cancer bone metastasis assessed with in vivo dual-modality imaging.

PubMed

Jeffery, Justin J; Lux, Katie; Vogel, John S; Herrera, Wynetta D; Greco, Stephen; Woo, Ho-Hyung; AbuShahin, Nisreen; Pagel, Mark D; Chambers, Setsuko K

2014-04-01

Breast cancer cells preferentially home to the bone microenvironment, which provides a unique niche with a network of multiple bidirectional communications between host and tumor, promoting survival and growth of bone metastases. In the bone microenvironment, the c-fms proto-oncogene that encodes for the CSF-1 receptor, along with CSF-1, serves as one critical cytokine/receptor pair, functioning in paracrine and autocrine fashion. Previous studies concentrated on the effect of inhibition of host (mouse) c-fms on bone metastasis, with resulting decrease in osteolysis and bone metastases as a paracrine effect. In this report, we assessed the role of c-fms inhibition within the tumor cells (autocrine effect) in the early establishment of breast cancer cells in bone and the effects of this early c-fms inhibition on subsequent bone metastases and destruction. This study exploited a multidisciplinary approach by employing two non-invasive, in vivo imaging methods to assess the progression of bone metastases and bone destruction, in addition to ex vivo analyses using RT-PCR and histopathology. Using a mouse model of bone homing human breast cancer cells, we showed that an early one-time application of anti-human c-fms antibody delayed growth of bone metastases and bone destruction for at least 31 days as quantitatively measured by bioluminescence imaging and computed tomography, compared to controls. Thus, neutralizing human c-fms in the breast cancer cell alone decreases extent of subsequent bone metastasis formation and osteolysis. Furthermore, we are the first to show that anti-c-fms antibodies can impact early establishment of breast cancer cells in bone.

An autocrine γ-aminobutyric acid signaling system exists in pancreatic β-cell progenitors of fetal and postnatal mice.

PubMed

Feng, Mary M; Xiang, Yun-Yan; Wang, Shuanglian; Lu, Wei-Yang

2013-01-01

Gamma-aminobutyric acid (GABA) is produced and secreted by adult pancreatic β-cells, which also express GABA receptors mediating autocrine signaling and regulating β-cell proliferation. However, whether the autocrine GABA signaling involves in β-cell progenitor development or maturation remains uncertain. By means of immunohistochemistry we analyzed the expression profiles of the GABA synthesizing enzyme glutamic acid decarboxylase (GAD) and the α1-subunit of type-A GABA receptor (GABAARα1) in the pancreas of mice at embryonic day 15.5 (E15.5), E18.5, postnatal day 1 (P1) and P7. Our data showed that at E15.5 the pancreatic and duodenum homeobox-1 (Pdx1) was expressed in the majority of cells in the developing pancreata. Notably, insulin immunoreactivity was identified in a subpopulation of pancreatic cells with a high level of Pdx1 expression. About 80% of the high-level Pdx-1 expressing cells in the pancreas expressed GAD and GABAARα1 at all pancreatic developmental stages. In contrast, only about 30% of the high-level Pdx-1 expressing cells in the E15.5 pancreas expressed insulin; i.e., a large number of GAD/GABAARα1-expressing cells did not express insulin at this early developmental stage. The expression level of GAD and GABAARα1 increased steadily, and progressively more GAD/GABAARα1-expressing cells expressed insulin in the course of pancreatic development. These results suggest that 1) GABA signaling proteins appear in β-cell progenitors prior to insulin expression; and 2) the increased expression of GABA signaling proteins may be involved in β-cell progenitor maturation.

High salt induces autocrine actions of ET-1 on inner medullary collecting duct NO production via upregulated ETB receptor expression.

PubMed

Hyndman, Kelly Anne; Dugas, Courtney; Arguello, Alexandra M; Goodchild, Traci T; Buckley, Kathleen M; Burch, Mariah; Yanagisawa, Masashi; Pollock, Jennifer S

2016-08-01

The collecting duct endothelin-1 (ET-1), endothelin B (ETB) receptor, and nitric oxide synthase-1 (NOS1) pathways are critical for regulation of fluid-electrolyte balance and blood pressure control during high-salt feeding. ET-1, ETB receptor, and NOS1 are highly expressed in the inner medullary collecting duct (IMCD) and vasa recta, suggesting that there may be cross talk or paracrine signaling between the vasa recta and IMCD. The purpose of this study was to test the hypothesis that endothelial cell-derived ET-1 (paracrine) and collecting duct-derived ET-1 (autocrine) promote IMCD nitric oxide (NO) production through activation of the ETB receptor during high-salt feeding. We determined that after 7 days of a high-salt diet (HS7), there was a shift to 100% ETB expression in IMCDs, as well as a twofold increase in nitrite production (a metabolite of NO), and this increase could be prevented by acute inhibition of the ETB receptor. ETB receptor blockade or NOS1 inhibition also prevented the ET-1-dependent decrease in ion transport from primary IMCDs, as determined by transepithelial resistance. IMCD were also isolated from vascular endothelial ET-1 knockout mice (VEETKO), collecting duct ET-1 KO (CDET-1KO), and flox controls. Nitrite production by IMCD from VEETKO and flox mice was similarly increased twofold with HS7. However, IMCD NO production from CDET-1KO mice was significantly blunted with HS7 compared with flox control. Taken together, these data indicate that during high-salt feeding, the autocrine actions of ET-1 via upregulation of the ETB receptor are critical for IMCD NO production, facilitating inhibition of ion reabsorption. Copyright © 2016 the American Physiological Society.

Periostin expression in intra-tumoral stromal cells is prognostic and predictive for colorectal carcinoma via creating a cancer-supportive niche

PubMed Central

Tan, Xiaojie; Ding, Yibo; Luo, Yanxin; Cai, Hui; Liu, Yan; Gao, Xianhua; Liu, Qizhi; Yu, Yongwei; Du, Yan; Wang, Hao; Ma, Liye; Wang, Jianping; Chen, Kun; Ding, Yanqing; Fu, Chuangang; Cao, Guangwen

2016-01-01

Periostin (POSTN) expression in cancer cells and circulation has been related to poor prognosis of colorectal carcinoma (CRC). However, the role of POSTN expressed in intra-tumoral stroma on CRC progression remains largely unknown. This study enrolled 1098 CRC patients who received surgical treatment in Shanghai and Guangzhou, Mainland China. In Shanghai cohort, immunohistochemistry score of stromal POSTN expression increased consecutively from adjacent mucosa, primary CRC tissues, to metastatic CRC tissues (P < 0.001), while medium- and high-stromal POSTN expression, rather than epithelial POSTN expression, independently predicted unfavorable prognoses of CRC, adjusted for covariates including TNM stage and postoperative chemotherapy in multivariate Cox models. The results in Shanghai cohort were faithfully replicated in Guangzhou cohort. Stromal POSTN expression dose-dependently predicted an unfavorable prognosis of stage III CRC patients with postoperative chemotherapy in both cohorts. POSTN derived from colonic fibroblasts or recombinant POSTN significantly promoted proliferation, anchorage independent growth, invasion, and chemo-resistance of CRC cells; whereas these effects were counteracted via targeting to PI3K/Akt or Wnt/β-catenin signaling pathway. CRC cell RKO-derived factor(s) significantly induced POSTN production in colonic fibroblasts and autocrine POSTN promoted proliferation, migration, and anchorage independent growth of fibroblasts. Conclusively, stromal POSTN is prognostic and predictive for CRC via creating a niche to facilitate cancer progression. Targeting POSTN-induced signaling pathways may be therapeutic options for metastatic or chemoresistant CRC. PMID:26556874

The crystal structure of a multifunctional protein: phosphoglucose isomerase/autocrine motility factor/neuroleukin.

PubMed

Sun, Y J; Chou, C C; Chen, W S; Wu, R T; Meng, M; Hsiao, C D

1999-05-11

Phosphoglucose isomerase (PGI) plays a central role in both the glycolysis and the gluconeogenesis pathways. We present here the complete crystal structure of PGI from Bacillus stearothermophilus at 2.3-A resolution. We show that PGI has cell-motility-stimulating activity on mouse colon cancer cells similar to that of endogenous autocrine motility factor (AMF). PGI can also enhance neurite outgrowth on neuronal progenitor cells similar to that observed for neuroleukin. The results confirm that PGI is neuroleukin and AMF. PGI has an open twisted alpha/beta structural motif consisting of two globular domains and two protruding parts. Based on this substrate-free structure, together with the previously published biological, biochemical, and modeling results, we postulate a possible substrate-binding site that is located within the domains' interface for PGI and AMF. In addition, the structure provides evidence suggesting that the top part of the large domain together with one of the protruding loops might participate in inducing the neurotrophic activity.

HCG variants, the growth factors which drive human malignancies

PubMed Central

Cole, Laurence A

2012-01-01

The term human chorionic gonadotropin (hCG) refers to a group of 5 molecules, each sharing the common amino acid sequence but each differing in meric structure and carbohydrate side chain structure. The 5 molecules are each produced by separate cells and each having separate biological functions. hCG and sulfated hCG are hormones produced by placental syncytiotrophoblast cells and pituitary gonadotrope cells. Hyperglycosylated hCG is an autocrine produced by placental cytotrophoblast cells. Hyperglycosylated hCG drives malignancy in placental cancers, and in testicular and ovarian germ cell malignancies. hCGβ and hyperglycosylated hCGβ are autocrines produce by most advanced malignancies. These molecules, particularly the malignancy promoters are presented in this review on hCG and cancer. hCGβ and hyperglycosylated hCGβ are critical to the growth and invasion, or malignancy of most advanced cancers. In many ways, while hCG may appear like a nothing, a hormone associated with pregnancy, it is not, and may be at the center of cancer research. PMID:22206043

YAP forms autocrine loops with the ERBB pathway to regulate ovarian cancer initiation and progression

PubMed Central

He, Chunbo; Lv, Xiangmin; Hua, Guohua; Lele, Subodh M; Remmenga, Steven; Dong, Jixin; Davis, John S; Wang, Cheng

2014-01-01

Mechanisms underlying ovarian cancer initiation and progression are unclear. Herein, we report that the Yes-associated protein (YAP), a major effector of the Hippo tumor suppressor pathway, interacts with ERBB signaling pathways to regulate the initiation and progression of ovarian cancer. Immunohistochemistry studies indicate that YAP expression is associated with poor clinical outcomes in patients. Overexpression or constitutive activation of YAP leads to transformation and tumorigenesis in human ovarian surface epithelial cells, and promotes growth of cancer cells in vivo and in vitro. YAP induces expression of EGF receptors (EGFR, ERBB3) and production of EGF-like ligands (HBEGF, NRG1 and NRG2). HBEGF or NRG1, in turn, activates YAP and stimulates cancer cell growth. Knockdown of ERBB3 or HBEGF eliminates YAP effects on cell growth and transformation, while knockdown of YAP abrogates NRG1- and HBEGF-stimulated cell proliferation. Collectively, our study demonstrates the existence of HBEGF&NRGs/ERBBs/YAP/HBEGF&NRGs autocrine loop that controls ovarian cell tumorigenesis and cancer progression. PMID:25798835

An FGF autocrine loop initiated in second heart field mesoderm regulates morphogenesis at the arterial pole of the heart

PubMed Central

Park, Eon Joo; Watanabe, Yusuke; Smyth, Graham; Miyagawa-Tomita, Sachiko; Meyers, Erik; Klingensmith, John; Camenisch, Todd; Buckingham, Margaret; Moon, Anne M.

2009-01-01

In order to understand how secreted signals regulate complex morphogenetic events, it is crucial to identify their cellular targets. By conditional inactivation of Fgfr1 and Fgfr2 and overexpression of the FGF antagonist sprouty 2 in different cell types, we have dissected the role of FGF signaling during heart outflow tract development in mouse. Contrary to expectation, cardiac neural crest and endothelial cells are not primary paracrine targets. FGF signaling within second heart field mesoderm is required for remodeling of the outflow tract: when disrupted, outflow myocardium fails to produce extracellular matrix and TGFβ and BMP signals essential for endothelial cell transformation and invasion of cardiac neural crest. We conclude that an autocrine regulatory loop, initiated by the reception of FGF signals by the mesoderm, regulates correct morphogenesis at the arterial pole of the heart. These findings provide new insight into how FGF signaling regulates context-dependent cellular responses during development. PMID:18832392

Tissue-specific Regulation of Porcine Prolactin Receptor Expression by Estrogen, Progesterone and Prolactin

USDA-ARS?s Scientific Manuscript database

Prolactin (PRL) acts through its receptor (PRLR) via both endocrine and local paracrine/autocrine pathways to regulate biological processes including reproduction and lactation. We analyzed the tissue and stage of gestation-specific regulation of PRL and PRLR expression in various tissues of pigs. ...

A novel first exon directs hormone-sensitive transcription of the pig prolactin receptor

USDA-ARS?s Scientific Manuscript database

Endocrine, paracrine, and autocrine prolactin (PRL) acts through its receptor (PRLR) to confer a wide range of biological functions, including its established role during lactation.We have identified a novel first exon of the porcine PRLR that gives rise to three different mRNA transcripts. Transcri...

Cooperativity Between Oncogenic PKC Epsilon and Pten Loss in Prostate Cancer Progression

DTIC Science & Technology

2016-10-01

objective of our studies is to elucidate the mechanisms by which PKCε, in conjunction with Pten loss, lead to malignant transformation and metastasis...ligand for the G-protein-coupled receptor CXCR5. This led us to hypothesize that PKCε in conjunction Pten deficienty activate an autonomous autocrine

Upregulation of circulating IL-15 by treadmill running in healthy individuals: is IL-15 an endocrine mediator of the beneficial effects of endurance exercise?

PubMed

Tamura, Yoshiaki; Watanabe, Keiichi; Kantani, Tomomi; Hayashi, Junichi; Ishida, Nobuhiko; Kaneki, Masao

2011-01-01

The beneficial effects of endurance exercise include insulin-sensitization and reduction of fat mass. Limited knowledge is available about the mechanisms by which endurance exercise exerts the salutary effects. Myokines, cytokines secreted by skeletal muscle, have been recognized as a potential mediator. Recently, a role of skeletal muscle-derived interleukin-15 (IL-15) in improvement of fat-lean body mass composition and insulin sensitivity has been proposed. Yet, previous studies have reported that endurance training does not increase production or secretion of IL-15 in skeletal muscle. Here, we show that in opposition to previous findings, 30-min treadmill running at 70% of age-predicted maximum heart rate resulted in a significant increase in circulating IL-15 level in untrained healthy young men. These findings suggest that IL-15 might play a role in the systemic anti-obesogenic and insulin-sensitizing effects of endurance exercise, not only as a paracrine and autocrine but also as an endocrine factor.

Development of Antidepressants as Novel Agents To Treat Small Cell Lung Cancer

DTIC Science & Technology

2014-08-01

least in part by the capacity of these drugs to disrupt autocrine survival loops between neuro - transmitters and their receptors at the surface of SCLC...Ser10 (p-H3; Millipore), cleaved caspase-3 (CC3; Cell Signal- ing Technology), insulin (DAKO), and synaptophysin (SYN; Neuro - mics). Alexa Fluor

Leukocytosis due to markedly elevated granulocyte-colony stimulating factor levels in a patient with endometrial cancer: Case report and literature review.

PubMed

Clark, Leslie H; Moll, Stephan; Houghton, Damon; O'Connor, Siohban; Soper, John T

2017-05-01

•Granulocyte-colony stimulating factor (GCSF) secretion by gynecologic tumors is rare.•Elevations in serum GCSF can be seen in the absence of tumor GSCF secretion.•Extreme leukocytosis is associated with autocrine tumor growth and poor prognosis.

Regulation of Prostate Development and Benign Prostatic Hyperplasia by Autocrine Cholinergic Signaling via Maintaining the Epithelial Progenitor Cells in Proliferating Status.

PubMed

Wang, Naitao; Dong, Bai-Jun; Quan, Yizhou; Chen, Qianqian; Chu, Mingliang; Xu, Jin; Xue, Wei; Huang, Yi-Ran; Yang, Ru; Gao, Wei-Qiang

2016-05-10

Regulation of prostate epithelial progenitor cells is important in prostate development and prostate diseases. Our previous study demonstrated a function of autocrine cholinergic signaling (ACS) in promoting prostate cancer growth and castration resistance. However, whether or not such ACS also plays a role in prostate development is unknown. Here, we report that ACS promoted the proliferation and inhibited the differentiation of prostate epithelial progenitor cells in organotypic cultures. These results were confirmed by ex vivo lineage tracing assays and in vivo renal capsule recombination assays. Moreover, we found that M3 cholinergic receptor (CHRM3) was upregulated in a large subset of benign prostatic hyperplasia (BPH) tissues compared with normal tissues. Activation of CHRM3 also promoted the proliferation of BPH cells. Together, our findings identify a role of ACS in maintaining prostate epithelial progenitor cells in the proliferating state, and blockade of ACS may have clinical implications for the management of BPH. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Regulation of myeloproliferation and M2 macrophage programming in mice by Lyn/Hck, SHIP, and Stat5

PubMed Central

Xiao, Wenbin; Hong, Hong; Kawakami, Yuko; Lowell, Clifford A.; Kawakami, Toshiaki

2008-01-01

The proliferation and differentiation of hematopoietic stem cells (HSCs) is finely regulated by extrinsic and intrinsic factors via various signaling pathways. Here we have shown that, similar to mice deficient in the lipid phosphatase SHIP, loss of 2 Src family kinases, Lyn and Hck, profoundly affects HSC differentiation, producing hematopoietic progenitors with increased proliferation, reduced apoptosis, growth factor–independent survival, and skewed differentiation toward M2 macrophages. This phenotype culminates in a Stat5-dependent myeloproliferative disease that is accompanied by M2 macrophage infiltration of the lung. Expression of a membrane-bound form of SHIP in HSCs lacking both Lyn and Hck restored normal hematopoiesis and prevented myeloproliferation. In vitro and in vivo studies suggested the involvement of autocrine and/or paracrine production of IL-3 and GM-CSF in the increased proliferation and myeloid differentiation of HSCs. Thus, this study has defined a myeloproliferative transformation-sensitive signaling pathway, composed of Lyn/Hck, SHIP, autocrine/paracrine cytokines, and Stat5, that regulates HSC differentiation and M2 macrophage programming. PMID:18246197

YAP forms autocrine loops with the ERBB pathway to regulate ovarian cancer initiation and progression.

PubMed

He, C; Lv, X; Hua, G; Lele, S M; Remmenga, S; Dong, J; Davis, J S; Wang, C

2015-12-10

Mechanisms underlying ovarian cancer initiation and progression are unclear. Herein, we report that the Yes-associated protein (YAP), a major effector of the Hippo tumor suppressor pathway, interacts with ERBB signaling pathways to regulate the initiation and progression of ovarian cancer. Immunohistochemistry studies indicate that YAP expression is associated with poor clinical outcomes in patients. Overexpression or constitutive activation of YAP leads to transformation and tumorigenesis in human ovarian surface epithelial cells, and promotes growth of cancer cells in vivo and in vitro. YAP induces the expression of epidermal growth factor (EGF) receptors (EGFR, ERBB3) and production of EGF-like ligands (HBEGF, NRG1 and NRG2). HBEGF or NRG1, in turn, activates YAP and stimulates cancer cell growth. Knockdown of ERBB3 or HBEGF eliminates YAP effects on cell growth and transformation, whereas knockdown of YAP abrogates NRG1- and HBEGF-stimulated cell proliferation. Collectively, our study demonstrates the existence of HBEGF & NRGs/ERBBs/YAP/HBEGF & NRGs autocrine loop that controls ovarian cell tumorigenesis and cancer progression.

IL-35 promotes pancreas cancer growth through enhancement of proliferation and inhibition of apoptosis: evidence for a role as an autocrine growth factor.

PubMed

Nicholl, Michael B; Ledgewood, Chelsea L; Chen, Xuhui; Bai, Qian; Qin, Chenglu; Cook, Kathryn M; Herrick, Elizabeth J; Diaz-Arias, Alberto; Moore, Bradley J; Fang, Yujiang

2014-12-01

Interleukin-35 (IL-35), an IL-12 cytokine family member, mediates the immune inhibitory function of regulatory T cells (Treg). We assayed the presence of IL-35 in paraffin-embedded human pancreas cancer (PCAN) and unexpectedly found IL-35 was expressed mainly by epithelial derived PCAN cells, but not by Treg. We further examined the expression and effect of exogenous IL-35 in human PCAN cell lines and found IL-35 promoted growth and inhibited apoptosis in PCAN cell lines. IL-35 induced proliferation correlated with an increase in cyclin B, cyclin D, cdk2, and cdk4 and a decrease in p27 expression, while inhibition of apoptosis was associated with an increase in Bcl-2 and a decrease in TRAILR1. We conclude IL-35 is produced by PCAN in vivo and promotes PCAN cell line growth in vitro. These results might indicate an important new role for IL-35 as an autocrine growth factor in PCAN growth. Copyright © 2014 Elsevier Ltd. All rights reserved.

Loss of MeCP2 disrupts cell autonomous and autocrine BDNF signaling in mouse glutamatergic neurons

PubMed Central

Sampathkumar, Charanya; Wu, Yuan-Ju; Vadhvani, Mayur; Trimbuch, Thorsten; Eickholt, Britta; Rosenmund, Christian

2016-01-01

Mutations in the MECP2 gene cause the neurodevelopmental disorder Rett syndrome (RTT). Previous studies have shown that altered MeCP2 levels result in aberrant neurite outgrowth and glutamatergic synapse formation. However, causal molecular mechanisms are not well understood since MeCP2 is known to regulate transcription of a wide range of target genes. Here, we describe a key role for a constitutive BDNF feed forward signaling pathway in regulating synaptic response, general growth and differentiation of glutamatergic neurons. Chronic block of TrkB receptors mimics the MeCP2 deficiency in wildtype glutamatergic neurons, while re-expression of BDNF quantitatively rescues MeCP2 deficiency. We show that BDNF acts cell autonomous and autocrine, as wildtype neurons are not capable of rescuing growth deficits in neighboring MeCP2 deficient neurons in vitro and in vivo. These findings are relevant for understanding RTT pathophysiology, wherein wildtype and mutant neurons are intermixed throughout the nervous system. DOI: http://dx.doi.org/10.7554/eLife.19374.001 PMID:27782879

Feedback amplification of fibrosis through matrix stiffening and COX-2 suppression

PubMed Central

Liu, Fei; Mih, Justin D.; Shea, Barry S.; Kho, Alvin T.; Sharif, Asma S.; Tager, Andrew M.

2010-01-01

Tissue stiffening is a hallmark of fibrotic disorders but has traditionally been regarded as an outcome of fibrosis, not a contributing factor to pathogenesis. In this study, we show that fibrosis induced by bleomycin injury in the murine lung locally increases median tissue stiffness sixfold relative to normal lung parenchyma. Across this pathophysiological stiffness range, cultured lung fibroblasts transition from a surprisingly quiescent state to progressive increases in proliferation and matrix synthesis, accompanied by coordinated decreases in matrix proteolytic gene expression. Increasing matrix stiffness strongly suppresses fibroblast expression of COX-2 (cyclooxygenase-2) and synthesis of prostaglandin E2 (PGE2), an autocrine inhibitor of fibrogenesis. Exogenous PGE2 or an agonist of the prostanoid EP2 receptor completely counteracts the proliferative and matrix synthetic effects caused by increased stiffness. Together, these results demonstrate a dominant role for normal tissue compliance, acting in part through autocrine PGE2, in maintaining fibroblast quiescence and reveal a feedback relationship between matrix stiffening, COX-2 suppression, and fibroblast activation that promotes and amplifies progressive fibrosis. PMID:20733059

Theileria parva infection induces autocrine growth of bovine lymphocytes.

PubMed Central

Dobbelaere, D A; Coquerelle, T M; Roditi, I J; Eichhorn, M; Williams, R O

1988-01-01

Bovine lymphocytes infected with the parasite Theileria parva continuously secrete a growth factor that is essential for their proliferation in vitro and also constitutively express interleukin 2 receptors on their surface. Dilution of the secreted growth factor, caused by culturing cells at low density, results in retardation of culture growth. Human recombinant interleukin 2, however, effectively substitutes for the diluted growth factor by restoring normal growth rates and also allows Theileria-infected cells to be grown at low density without the use of feeder layers. Secretion of the growth factor and expression of the interleukin 2 receptor depend on the presence of the parasite in the cytoplasm of the host cell. Elimination of the parasite from the cell cytoplasm by the specific antitheilerial drug BW 720c results in the arrest of growth factor secretion and the disappearance of interleukin 2 receptors from the cell surface. This is accompanied by growth arrest and reversion of the infected cells to the morphology of resting lymphocytes. We propose that the continuous proliferation of infected cells in vitro is mediated by autocrine receptor activation. Images PMID:3133661

Binding of FGF2 to FGFR2 in an autocrine mode in trophectoderm cells is indispensable for mouse blastocyst formation through PKC-p38 pathway.

PubMed

Yang, Jing; Zhang, Dan; Yu, Ying; Zhang, Run-Ju; Hu, Xiao-Ling; Huang, He-Feng; Lu, Yong-Chao

2015-01-01

Fibroblast growth factors (FGF1, FGF2 and FGF4) and fibroblast growth factor receptors (FGFR1, FGFR2, FGFR3 and FGFR4) have been reported to be expressed in preimplantation embryos and be required for their development. However, the functions of these molecules in trophectoderm cells (TEs) that lead to the formation of the blastocyst as well as the underlying mechanism have not been elucidated. The present study has demonstrated for the first time that endogenous FGF2 secreted by TEs can regulate protein expression and distribution in TEs via the FGFR2-mediated activation of PKC and p38, which are important for the development of expanded blastocysts. This finding provides the first explanation for the long-observed phenomenon that only high concentrations of exogenous FGFs have effects on embryonic development, but in vivo the amount of endogenous FGFs are trace. Besides, the present results suggest that FGF2/FGFR2 may act in an autocrine fashion and activate the downstream PKC/p38 pathway in TEs during expanded blastocyst formation.

Role of Endogenous Cholecystokinin on Growth of Human Pancreatic Cancer

PubMed Central

Matters, Gail L.; McGovern, Christopher; Harms, John F.; Markovic, Kevin; Anson, Krystal; Jayakumar, Calpurnia; Martenis, Melissa; Awad, Christina; Smith, Jill P.

2012-01-01

Cholecystokinin (CCK) and gastrin stimulate growth of pancreatic cancer. Although down regulation of gastrin inhibits growth of pancreatic cancer, the contribution of endogenous CCK to tumor growth is unknown. The purpose of this study was to evaluate the role of endogenous CCK on autocrine growth of pancreatic cancer. Pancreatic cancer cell lines were analyzed for CCK mRNA and peptide expression by real time RT-PCR and radioimmunoassay, respectively. The effect of endogenous CCK on growth was evaluated by treating cancer cells with CCK neutralizing antibodies and by down regulating CCK mRNA by RNAi. Wild type pancreatic cancer cells expressed significantly lower CCK mRNA and peptide levels than gastrin. Neither treatment of pancreatic cancer cells with CCK antibodies nor the down regulation of CCK mRNA and peptide by shRNAs altered growth in vitro or in vivo. Conversely, when gastrin mRNA expression was down regulated, the same cells failed to produce tumors in spite of having sustained levels of endogenous CCK. Pancreatic cancer cells produce CCK and gastrin; however, the autocrine production of gastrin is more important for stimulating tumor growth. PMID:21186400

Mucin1 mediates autocrine transforming growth factor beta signaling through activating the c-Jun N-terminal kinase/activator protein 1 pathway in human hepatocellular carcinoma cells.

PubMed

Li, Qiongshu; Liu, Guomu; Shao, Dan; Wang, Juan; Yuan, Hongyan; Chen, Tanxiu; Zhai, Ruiping; Ni, Weihua; Tai, Guixiang

2015-02-01

In a previous study, we observed by global gene expression analysis that oncogene mucin1 (MUC1) silencing decreased transforming growth factor beta (TGF-β) signaling in the human hepatocellular carcinoma (HCC) cell line SMMC-7721. In this study, we report that MUC1 overexpression enhanced the levels of phosphorylated Smad3 linker region (p-Smad3L) (Ser-213) and its target gene MMP-9 in HCC cells, suggesting that MUC1 mediates TGF-β signaling. To investigate the effect of MUC1 on TGF-β signaling, we determined TGF-β secretion in MUC1 gene silencing and overexpressing cell lines. MUC1 expression enhanced not only TGF-β1 expression at the mRNA and protein levels but also luciferase activity driven by a TGF-β promoter, as well as elevated the activation of c-Jun N-terminal kinase (JNK) and c-Jun, a member of the activation protein 1 (AP-1) transcription factor family. Furthermore, pharmacological reduction of TGF-β receptor (TβR), JNK and c-Jun activity inhibited MUC1-induced autocrine TGF-β signaling. Moreover, a co-immunoprecipitation assay showed that MUC1 directly bound and activated JNK. In addition, both MUC1-induced TGF-β secretion and exogenous TGF-β1 significantly increased Smad signaling and cell migration, which were markedly inhibited by either TβR inhibitor or small interfering RNA silencing of TGF-β1 gene in HCC cells. The high correlation between MUC1 and TGF-β1 or p-Smad3L (Ser-213) expression was shown in tumor tissues from HCC patients by immunohistochemical staining analysis. Collectively, these results indicate that MUC1 mediates autocrine TGF-β signaling by activating the JNK/AP-1 pathway in HCC cells. Therefore, MUC1 plays a key role in HCC progression and could serve as an attractive target for HCC therapy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Autocrine pathways involving S100A8 and/or S100A9 that are postulated to regulate the immunological functions of macrophages in rats.

PubMed

Okada, Kohki; Arai, Satoshi; Nakase, Hiroshi; Kohno, Hisashi; Nakamura, Fumihiko; Takeda, Mayu; Toda, Yoshinobu; Itoh, Hiroshi; Adachi, Souichi; Ikemoto, Masaki

2015-01-02

The development of ulcerative colitis (UC) is closely associated with abnormally functioning macrophages. Rat S100A8 (r-S100A8) and r-S100A9 (S100 proteins) is abundantly expressed in immune cells of myeloid origin, macrophages; however, it remains unclear why r-S100A9 is dominantly expressed in the macrophages of UC rats (UCR). The purpose of this study was to verify the immunological roles of S100 proteins in UCR. We observed the distribution of S100 protein-positive macrophages in the large colons of UCR using a fluorescent immunological staining method, so that S100 protein-positive macrophages were restricted to the rectal tissues of the UCR, and that the mRNA levels of r-S100A8 and r-S100A9 were up-regulated by stimulation with recombinant rat S100A8 (rr-S100A8) alone and rr-S100A9 alone, respectively. When the changes in the mRNA levels of r-S100A8 and r-S100A9 in macrophages were examined in in vitro study by PCR and real-time PCR, the mRNA levels of anti-inflammatory and inflammatory cytokines increased selectively after stimulation with rr-S100A8 alone and rr-S100A9 alone, respectively. These results suggest that autocrine signal transduction pathways involving S100 proteins regulate the immunological functions of macrophages to maintain homeostasis in the gastrointestinal tract. This may be depended on expression balance of S100 proteins in macrophages. It is strongly suggested that in UCR the immune functions of macrophages are regulated in a complex manner by r-S100A8 and/or r-S100A9 through undefined autocrine pathways on the cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Platelet-Derived Growth Factor Receptor Activation Promotes the Prodestructive Invadosome-Forming Phenotype of Synoviocytes from Patients with Rheumatoid Arthritis.

PubMed

Charbonneau, Martine; Lavoie, Roxane R; Lauzier, Annie; Harper, Kelly; McDonald, Patrick P; Dubois, Claire M

2016-04-15

Fibroblast-like synoviocytes (FLS) play a major role in invasive joint destruction in rheumatoid arthritis (RA). This prodestructive phenotype has been shown to involve autocrine TGF-β that triggers formation of matrix-degrading invadosomes through molecular mechanisms that are not fully elucidated. The platelet-derived growth factor (PDGF) receptor (PDGFR) family of receptor tyrosine kinases (RTK) has been shown to cooperate with TGF-β in various pathological conditions. We therefore sought to determine whether RTK activity played a role in invadosome biogenesis. We demonstrated that, among the common RTKs, PDGFR-αβ was specifically phosphorylated in FLS from RA patients. Phosphorylation of PDGFR-αβ was also elevated in RA synovial tissues. Interference with PDGFR activation or PDGF neutralization inhibited invadosome formation in RA synoviocytes, indicating the presence of an autocrine PDGFR activation loop that involved endogenous PDGF. Among the PDGF-A-D isoforms, only PDGF-B was found both significantly elevated in FLS lines from RA patients, and related to high-invadosome forming cells. Addition of TGF-β upregulated invadosome formation, PDGF-B mRNA expression, and phosphorylation of PDGFR. All of these functions were efficiently suppressed by TGF-β neutralization or interference with the Smad/TβR1or PI3K/Akt pathway. Among the class 1 PI3K family proteins known to be expressed in RA synoviocytes, PI3Kα was selectively involved in PDGF-B expression, whereas both PI3Kα and PI3Kδ participated in invadosome formation. Our findings demonstrate that PDGFR is a critical RTK required for the prodestructive phenotype of RA synovial cells. They also provide evidence for an association between autocrine TGF-β and PDGFR-mediated invadosome formation in RA synoviocytes that involves the production of PDGF-B induced by TGF-β. Copyright © 2016 by The American Association of Immunologists, Inc.

RFamide-related peptide 3 and gonadotropin-releasing hormone-II are autocrine-paracrine regulators of testicular function in the boar

USDA-ARS?s Scientific Manuscript database

Widespread use of artificial insemination in swine requires millions of doses of boar semen each year. Subfertility of boars remains a major constraint, which can impact the reproductive efficiency of thousands of sows, so a better understanding of testicular function is needed in order to develop m...

Knockdown of the GnRH-II receptor in the porcine testis impairs the biosynthesis of 10 gonadal steroids

USDA-ARS?s Scientific Manuscript database

The second mammalian GnRH isoform (GnRH-II) and its cognate receptor (GnRHR-II) are poor modulators of gonadotropin secretion in swine. However, both are abundantly produced within the porcine testis suggesting an autocrine/paracrine role. Within the boar testis, GnRHR-II immunolocalizes to the plas...

Molecular Markers for Breast Cancer Susceptibility.

DTIC Science & Technology

1998-09-01

Guzman, R. C., Osborn, R. C., Thordarson , G., and Nandi, S. for 1 h, and then the coverslips were rinsed in 1 x PBS for 3 min three Role of... Thordarson G, Nandi S 21. Huguet EL, Smith K, Bicknell R, Harris AL 1995 Regula- 1992 Role of endocrine, autocrine, and paracrine inter- tion of Wnt5a

New discoveries on the biology and detection of human chorionic gonadotropin

PubMed Central

Cole, Laurence A

2009-01-01

Human chorionic gonadotropin (hCG) is a glycoprotein hormone comprising 2 subunits, alpha and beta joined non covalently. While similar in structure to luteinizing hormone (LH), hCG exists in multiple hormonal and non-endocrine agents, rather than as a single molecule like LH and the other glycoprotein hormones. These are regular hCG, hyperglycosylated hCG and the free beta-subunit of hyperglycosylated hCG. For 88 years regular hCG has been known as a promoter of corpus luteal progesterone production, even though this function only explains 3 weeks of a full gestations production of regular hCG. Research in recent years has explained the full gestational production by demonstration of critical functions in trophoblast differentiation and in fetal nutrition through myometrial spiral artery angiogenesis. While regular hCG is made by fused villous syncytiotrophoblast cells, extravillous invasive cytotrophoblast cells make the variant hyperglycosylated hCG. This variant is an autocrine factor, acting on extravillous invasive cytotrophoblast cells to initiate and control invasion as occurs at implantation of pregnancy and the establishment of hemochorial placentation, and malignancy as occurs in invasive hydatidiform mole and choriocarcinoma. Hyperglycosylated hCG inhibits apoptosis in extravillous invasive cytotrophoblast cells promoting cell invasion, growth and malignancy. Other non-trophoblastic malignancies retro-differentiate and produce a hyperglycosylated free beta-subunit of hCG (hCG free beta). This has been shown to be an autocrine factor antagonizing apoptosis furthering cancer cell growth and malignancy. New applications have been demonstrated for total hCG measurements and detection of the 3 hCG variants in pregnancy detection, monitoring pregnancy outcome, determining risk for Down syndrome fetus, predicting preeclampsia, detecting pituitary hCG, detecting and managing gestational trophoblastic diseases, diagnosing quiescent gestational trophoblastic disease, diagnosing placental site trophoblastic tumor, managing testicular germ cell malignancies, and monitoring other human malignancies. There are very few molecules with such wide and varying functions as regular hCG and its variants, and very few tests with such a wide spectrum of clinical applications as total hCG. PMID:19171054

Early Prediction of Persistent Organ Failure by Serum Angiopoietin-2 in Patients with Acute Pancreatitis.

PubMed

Zhang, Yu-Ping; Liu, Chang; Ye, Lei; Yu, Na; Ye, Yuan-Ning; Sun, Wen-Rong; Wu, Lin; Wang, Fang-Yu

2016-12-01

Biomarkers for the early prediction of the severity of acute pancreatitis (AP) are urgently needed for clinical management of the disease. Angiopoietin-2 (Ang-2), one of the autocrine peptides that reduce endothelial permeability, has been found to be associated with various diseases, including inflammatory disorders. This study aimed to determine whether serum Ang-2 could serve as a noninvasive biomarker for the early prediction of persistent organ failure (POF) in acute pancreatitis. A total of 120 AP patients were prospectively enrolled at Jinling Hospital. Serum samples were collected on admission. Clinical and laboratory data were recorded. Ang-2 levels were measured by enzyme-linked immunosorbent assay. A total of 37 patients developed POF and were classified as having severe AP (SAP). Ang-2 was significantly higher on admission in patients who developed POF than in those who did not (p < 0.001 for all). Furthermore, receiver operating characteristic (ROC) curve analysis revealed that Ang-2 could distinguish patients who developed POF from mild AP (MAP, area under ROC curve [AUC] = 0.88, 95 % CI 0.78-0.94) and moderately severe AP patients (MSAP, AUC = 0.74, 95 % CI 0.63-0.83). In addition, multivariate logistic regression showed that increased Ang-2 was an independent predictor of developing POF between subgroups with MSAP and SAP (OR 7.2, 95 % CI 2.7-19.4) and among all AP patients (OR 12.1, 95 % CI 4.8-30.3). Elevated serum Ang-2 levels on admission may be a promising biomarker for the prediction of POF in AP.

A local autocrine axis in the testes that regulates spermatogenesis

PubMed Central

Cheng, C. Yan; Mruk, Dolores D.

2014-01-01

Spermiation—the release of mature spermatozoa from Sertoli cells into the seminiferous tubule lumen—occurs by the disruption of an anchoring device known as the apical ectoplasmic specialization (apical ES). At the same time, the blood–testis barrier (BTB) undergoes extensive restructuring to facilitate the transit of preleptotene spermatocytes. While these two cellular events take place at opposite ends of the Sertoli cell epithelium, the events are in fact tightly coordinated, as any disruption in either process will lead to infertility. A local regulatory axis exists between the apical ES and the BTB in which biologically active laminin fragments produced at the apical ES by the action of matrix metalloproteinase 2 can regulate BTB restructuring directly or indirectly via the hemidesmosome. Equally important, polarity proteins play a crucial part in coordinating cellular events within this apical ES–BTB–hemidesmosome axis. Additionally, testosterone and cytokines work in concert to facilitate BTB restructuring, which enables the transit of spermatocytes while maintaining immunological barrier function. Herein, we will discuss this important autocrine-based cellular axis that parallels the hormonal-based hypothalamic–pituitary–testicular axis that regulates spermatogenesis. This local regulatory axis is the emerging target for male contraception. PMID:20571538

Monocyte/Macrophage-derived IGF-1 Orchestrates Murine Skeletal Muscle Regeneration and Modulates Autocrine Polarization

PubMed Central

Tonkin, Joanne; Temmerman, Lieve; Sampson, Robert D; Gallego-Colon, Enrique; Barberi, Laura; Bilbao, Daniel; Schneider, Michael D; Musarò, Antonio; Rosenthal, Nadia

2015-01-01

Insulin-like growth factor 1 (IGF-1) is a potent enhancer of tissue regeneration, and its overexpression in muscle injury leads to hastened resolution of the inflammatory phase. Here, we show that monocytes/macrophages constitute an important initial source of IGF-1 in muscle injury, as conditional deletion of the IGF-1 gene specifically in mouse myeloid cells (ϕIGF-1 CKO) blocked the normal surge of local IGF-1 in damaged muscle and significantly compromised regeneration. In injured muscle, Ly6C+ monocytes/macrophages and CD206+ macrophages expressed equivalent IGF-1 levels, which were transiently upregulated during transition from the inflammation to repair. In injured ϕIGF-1 CKO mouse muscle, accumulation of CD206+ macrophages was impaired, while an increase in Ly6C+ monocytes/macrophages was favored. Transcriptional profiling uncovered inflammatory skewing in ϕIGF-1 CKO macrophages, which failed to fully induce a reparative gene program in vitro or in vivo, revealing a novel autocrine role for IGF-1 in modulating murine macrophage phenotypes. These data establish local macrophage-derived IGF-1 as a key factor in inflammation resolution and macrophage polarization during muscle regeneration. PMID:25896247

Autocrine Complement Inhibits IL10-Dependent T-Cell Mediated Antitumor Immunity to Promote Tumor Progression

PubMed Central

Wang, Yu; Sun, Sheng-Nan; Liu, Qing; Yu, Yang-Yang; Guo, Jian; Wang, Kun; Xing, Bao-Cai; Zheng, Qing-Feng; Campa, Michael J.; Patz, Edward F.; Li, Shi-You; He, You-Wen

2016-01-01

In contrast to its inhibitory effects on many cells, IL-10 activates CD8+ tumor infiltrating lymphocytes (TILs) and enhances their antitumor activity. However, CD8+ TILs do not routinely express IL-10 as autocrine complement C3 inhibits IL-10 production through complement receptors C3aR and C5aR. CD8+ TILs from C3-deficient mice, however, express IL-10 and exhibit enhanced effector function. C3-deficient mice are resistant to tumor development in a T cell- and IL-10-dependent manner; human TILs expanded with IL-2 plus IL-10 increase the killing of primary tumors in vitro compared to IL-2 treated TILs. Complement-mediated inhibition of antitumor immunity is independent of the PD-1/PD-L1 immune checkpoint pathway. Our findings suggest that complement receptors C3aR and C5aR expressed on CD8+ TILs represent a novel class of immune checkpoints that could be targeted for tumor immunotherapy. Moreover, incorporation of IL-10 in the expansion of TILs and in gene-engineered T cells for adoptive cell therapy enhances their antitumor efficacy. PMID:27297552

Extracellular zinc and ATP-gated P2X receptor calcium entry channels: New zinc receptors as physiological sensors and therapeutic targets.

PubMed

Schwiebert, Erik M; Liang, Lihua; Cheng, Nai-Lin; Williams, Clintoria Richards; Olteanu, Dragos; Welty, Elisabeth A; Zsembery, Akos

2005-12-01

In this review, we focus on two attributes of P2X receptor channel function, one essential and one novel. First, we propose that P2X receptors are extracellular sensors as well as receptors and ion channels. In particular, the large extracellular domain (that comprises 70% of the molecular mass of the receptor channel protein) lends itself to be a cellular sensor. Moreover, its exquisite sensitivity to extracellular pH, ionic strength, and multiple ligands evokes the function of a sensor. Second, we propose that P2X receptors are extracellular zinc receptors as well as receptors for nucleotides. We provide novel data in multiple publications and illustrative data in this invited review to suggest that zinc triggers ATP-independent activation of P2X receptor channel function. In this light, P2X receptors are the cellular site of integration between autocrine and paracrine zinc signaling and autocrine and paracrine purinergic signaling. P2X receptors may sense changes in these ligands as well as in extracellular pH and ionic strength and transduce these sensations via calcium and/or sodium entry and changes in membrane potential.

FGF19 functions as autocrine growth factor for hepatoblastoma

PubMed Central

Elzi, David J.; Song, Meihua; Blackman, Barron; Weintraub, Susan T.; López-Terrada, Dolores; Chen, Yidong; Tomlinson, Gail E.; Shiio, Yuzuru

2016-01-01

Hepatoblastoma is the most common liver cancer in children, accounting for over 65% of all childhood liver malignancies. Hepatoblastoma is distinct from adult liver cancer in that it is not associated with hepatitis virus infection, cirrhosis, or other underlying liver pathology. The paucity of appropriate cell and animal models has been hampering the mechanistic understanding of hepatoblastoma pathogenesis. Consequently, there is no molecularly targeted therapy for hepatoblastoma. To gain insight into cytokine signaling in hepatoblastoma, we employed mass spectrometry to analyze the proteins secreted from Hep293TT hepatoblastoma cell line we established and identified the specific secretion of fibroblast growth factor 19 (FGF19), a growth factor for liver cells. We determined that silencing FGF19 by shRNAs or neutralizing secreted FGF19 by anti-FGF19 antibody inhibits the proliferation of hepatoblastoma cells. Furthermore, blocking FGF19 signaling by an FGF receptor kinase inhibitor suppressed hepatoblastoma growth. RNA expression analysis in hepatoblastoma tumors revealed that the high expression of FGF19 signaling pathway components as well as the low expression of FGF19 signaling repression targets correlates with the aggressiveness of the tumors. These results suggest the role of FGF19 as autocrine growth factor for hepatoblastoma. PMID:27382436

Autocrine selection of a GLP-1R G-protein biased agonist with potent antidiabetic effects.

PubMed

Zhang, Hongkai; Sturchler, Emmanuel; Zhu, Jiang; Nieto, Ainhoa; Cistrone, Philip A; Xie, Jia; He, LinLing; Yea, Kyungmoo; Jones, Teresa; Turn, Rachel; Di Stefano, Peter S; Griffin, Patrick R; Dawson, Philip E; McDonald, Patricia H; Lerner, Richard A

2015-12-01

Glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonists have emerged as treatment options for type 2 diabetes mellitus (T2DM). GLP-1R signals through G-protein-dependent, and G-protein-independent pathways by engaging the scaffold protein β-arrestin; preferential signalling of ligands through one or the other of these branches is known as 'ligand bias'. Here we report the discovery of the potent and selective GLP-1R G-protein-biased agonist, P5. We identified P5 in a high-throughput autocrine-based screening of large combinatorial peptide libraries, and show that P5 promotes G-protein signalling comparable to GLP-1 and Exendin-4, but exhibited a significantly reduced β-arrestin response. Preclinical studies using different mouse models of T2DM demonstrate that P5 is a weak insulin secretagogue. Nevertheless, chronic treatment of diabetic mice with P5 increased adipogenesis, reduced adipose tissue inflammation as well as hepatic steatosis and was more effective at correcting hyperglycaemia and lowering haemoglobin A1c levels than Exendin-4, suggesting that GLP-1R G-protein-biased agonists may provide a novel therapeutic approach to T2DM.

Angiotensin II promotes the proliferation of activated pancreatic stellate cells by Smad7 induction through a protein kinase C pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hama, Kouji; Ohnishi, Hirohide; Aoki, Hiroyoshi

2006-02-17

Activated pancreatic stellate cells (PSCs) play major roles in promoting pancreatic fibrosis. We previously reported that angiotensin II (Ang II) enhances activated PSC proliferation through EGF receptor transactivation. In the present study, we elucidated a novel intracellular mechanism by which Ang II stimulates cellular proliferation. TGF-{beta}{sub 1} inhibits activated PSC proliferation via a Smad3 and Smad4-dependent pathway in an autocrine manner. We demonstrated that Ang II inhibited TGF-{beta}{sub 1}-induced nuclear accumulation of Smad3 and Smad4. Furthermore, Ang II rapidly induced inhibitory Smad7 mRNA expression. Adenovirus-mediated Smad7 overexpression inhibited TGF-{beta}{sub 1}-induced nuclear accumulation of Smad3 and Smad4, and potentiated activated PSCmore » proliferation. PKC inhibitor Go6983 blocked the induction of Smad7 mRNA expression by Ang II. In addition, 12-O-tetradecanoyl-phorbol 13-acetate, a PKC activator, increased Smad7 mRNA expression. These results suggest that Ang II enhances activated PSC proliferation by blocking autocrine TGF-{beta}{sub 1}-mediated growth inhibition by inducing Smad7 expression via a PKC-dependent pathway.« less

Autocrine signal transmission with extracellular ligand degradation

NASA Astrophysics Data System (ADS)

Muratov, C B; Posta, F; Shvartsman, S Y

2009-03-01

Traveling waves of cell signaling in epithelial layers orchestrate a number of important processes in developing and adult tissues. These waves can be mediated by positive feedback autocrine loops, a mode of cell signaling where binding of a diffusible extracellular ligand to a cell surface receptor can lead to further ligand release. We formulate and analyze a biophysical model that accounts for ligand-induced ligand release, extracellular ligand diffusion and ligand-receptor interaction. We focus on the case when the main mode for ligand degradation is extracellular and analyze the problem with the sharp threshold positive feedback nonlinearity. We derive expressions that link the speed of propagation and other characteristics of traveling waves to the parameters of the biophysical processes, such as diffusion rates, receptor expression level, etc. Analyzing the derived expressions we found that traveling waves in such systems can exhibit a number of unusual properties, e.g. non-monotonic dependence of the speed of propagation on ligand diffusivity. Our results for the fully developed traveling fronts can be used to analyze wave initiation from localized perturbations, a scenario that frequently arises in the in vitro models of epithelial wound healing, and guide future modeling studies of cell communication in epithelial layers.

CXCL1 induces senescence of cancer-associated fibroblasts via autocrine loops in oral squamous cell carcinoma

PubMed Central

Kim, Eun Kyoung; Moon, Sook; Kim, Do Kyeong; Zhang, Xianglan

2018-01-01

Cancer-associated fibroblasts (CAFs) have emerged as one of the main factors related to cancer progression, however, the conversion mechanism of normal fibroblasts (NOFs) to CAFs has not been well elucidated. The aim of this study was to investigate the underlying mechanism of CAF transformation from NOFs in oral squamous cell carcinoma (OSCC). This study found that NOFs exposed to OSCC cells transformed to senescent cells. The cytokine antibody array showed the highest secretion levels of IL-6 and CXCL1 in NOFs co-cultured with OSCC cells. Despite that both IL-6 and CXCL1 induced the senescent phenotype of CAFs, CXCL1 secretion showed a cancer-specific response to transform NOFs into CAFs in OSCC, whereas IL-6 secretion was eventuated by common co-culture condition. Further, CXCL1 was released from NOFs co-cultured with OSCC cells, however, CXCL1 was undetectable in mono-cultured NOFs or co-cultured OSCC cells with NOFs. Taken together, this study demonstrates that CXCL1 can transform NOFs into senescent CAFs via an autocrine mechanism. These data might contribute to further understanding of CAFs and to development of a potential therapeutic approach targeting cancer cells-CAFs interactions. PMID:29360827

Role of ACTH in the Interactive/Paracrine Regulation of Adrenal Steroid Secretion in Physiological and Pathophysiological Conditions

PubMed Central

Lefebvre, Hervé; Thomas, Michaël; Duparc, Céline; Bertherat, Jérôme; Louiset, Estelle

2016-01-01

In the normal human adrenal gland, steroid secretion is regulated by a complex network of autocrine/paracrine interactions involving bioactive signals released by endothelial cells, nerve terminals, chromaffin cells, immunocompetent cells, and adrenocortical cells themselves. ACTH can be locally produced by medullary chromaffin cells and is, therefore, a major mediator of the corticomedullary functional interplay. Plasma ACTH also triggers the release of angiogenic and vasoactive agents from adrenocortical cells and adrenal mast cells and, thus, indirectly regulates steroid production through modulation of the adrenal blood flow. Adrenocortical neoplasms associated with steroid hypersecretion exhibit molecular and cellular defects that tend to reinforce the influence of paracrine regulatory loops on corticosteroidogenesis. Especially, ACTH has been found to be abnormally synthesized in bilateral macronodular adrenal hyperplasia responsible for hypercortisolism. In these tissues, ACTH is detected in a subpopulation of adrenocortical cells that express gonadal markers. This observation suggests that ectopic production of ACTH may result from impaired embryogenesis leading to abnormal maturation of the adrenogonadal primordium. Globally, the current literature indicates that ACTH is a major player in the autocrine/paracrine processes occurring in the adrenal gland in both physiological and pathological conditions. PMID:27489549

The heart as an extravascular target of endothelin-1 in ...

EPA Pesticide Factsheets

Exposure to particulate matter air pollution has been causally linked to cardiovascular disease in humans. Several broad and overlapping hypotheses describing the biological mechanisms by which particulate matter exposure leads to cardiovascular disease and cardiac dysfunction have been explored, though linkage with specific factors or genes remains limited. Given evidence pointing to autocrine/paracrine signaling systems as modulators of cardiac dysfunction, the present review highlights the emerging role of endothelins as mediators of cardiac dysfunction following particulate matter exposure. Endothelin-1 is a small multifunctional protein expressed in the pulmonary and cardiovascular system, known for its ability to constrict blood vessels. Although endothelin-1 can also directly and indirectly (via secondary signaling events) modulate cardiac contractility, heart rate, and rhythm, research on the role of endothelins in the context of air pollution has tended to focus on the vascular effects. The plausibility of endothelin as a mechanism underlying particulate matter-induced cardiac dysfunction is further supported by the therapeutic utility of certain endothelin receptor antagonists. Extravascular effects of endothelin on the heart could better explain one mechanism by which particulate matter exposure may lead to cardiac dysfunction. We propose and support the novel hypothesis that autocrine/paracrine signaling systems, such as endothelins, mediate cardiac

IL-1beta suppresses the formation of osteoclasts by increasing OPG production via an autocrine mechanism involving celecoxib-related prostaglandins in chondrocytes.

PubMed

Watanabe, Yusuke; Namba, Aki; Aida, Yukiko; Honda, Kazuhiro; Tanaka, Hideki; Suzuki, Naoto; Matsumura, Hideo; Maeno, Masao

2009-01-01

Elevated interleukin (IL)-1 concentrations in synovial fluid have been implicated in joint bone and cartilage destruction. Previously, we showed that IL-1beta stimulated the expression of prostaglandin (PG) receptor EP4 via increased PGE(2) production. However, the effect of IL-1beta on osteoclast formation via chondrocytes is unclear. Therefore, we examined the effect of IL-1beta and/or celecoxib on the expression of macrophage colony-stimulating factor (M-CSF), receptor activator of NF-kappaB ligand (RANKL), and osteoprotegerin (OPG) in human chondrocytes, and the indirect effect of IL-1beta on osteoclast-like cell formation using RAW264.7 cells. OPG and RANKL expression increased with IL-1beta; whereas M-CSF expression decreased. Celecoxib blocked the stimulatory effect of IL-1beta. Conditioned medium from IL-1beta-treated chondrocytes decreased TRAP staining in RAW264.7 cells. These results suggest that IL-1beta suppresses the formation of osteoclast-like cells via increased OPG production and decreased M-CSF production in chondrocytes, and OPG production may increase through an autocrine mechanism involving celecoxib-related PGs.

Concise Review: Multifaceted Characterization of Human Mesenchymal Stem Cells for Use in Regenerative Medicine

PubMed Central

Samsonraj, Rebekah M.; Raghunath, Michael; Nurcombe, Victor; Hui, James H.

2017-01-01

Abstract Mesenchymal stem cells (MSC) hold great potential for regenerative medicine because of their ability for self‐renewal and differentiation into tissue‐specific cells such as osteoblasts, chondrocytes, and adipocytes. MSCs orchestrate tissue development, maintenance and repair, and are useful for musculoskeletal regenerative therapies to treat age‐related orthopedic degenerative diseases and other clinical conditions. Importantly, MSCs produce secretory factors that play critical roles in tissue repair that support both engraftment and trophic functions (autocrine and paracrine). The development of uniform protocols for both preparation and characterization of MSCs, including standardized functional assays for evaluation of their biological potential, are critical factors contributing to their clinical utility. Quality control and release criteria for MSCs should include cell surface markers, differentiation potential, and other essential cell parameters. For example, cell surface marker profiles (surfactome), bone‐forming capacities in ectopic and orthotopic models, as well as cell size and granularity, telomere length, senescence status, trophic factor secretion (secretome), and immunomodulation, should be thoroughly assessed to predict MSC utility for regenerative medicine. We propose that these and other functionalities of MSCs should be characterized prior to use in clinical applications as part of comprehensive and uniform guidelines and release criteria for their clinical‐grade production to achieve predictably favorable treatment outcomes for stem cell therapy. Stem Cells Translational Medicine 2017;6:2173–2185 PMID:29076267

In vitro treatment with 17,20b-dihydroxy-4-pregnen-3-one regulates mRNA levels of transforming growth factor beta superfamily members in rainbow trout (Oncorhynchus mykiss) ovarian tissue

USDA-ARS?s Scientific Manuscript database

Transforming growth factor beta (TGFB) superfamily members are important paracrine/autocrine regulators of ovarian development and steroidogenesis in mammals, but their reproductive role in fishes is not well understood. Our objectives were 3-fold: to determine if key TGFB superfamily transcripts a...

Autocrine A2 in the T-System of Ventricular Myocytes Creates Transmural Gradients in Ion Transport: A Mechanism to Match Contraction with Load?

PubMed Central

Gao, Junyuan; Sun, Xiurong; Potapova, Irina A.; Cohen, Ira S.; Mathias, Richard T.; Kim, Jeremy H.

2014-01-01

Transmural heterogeneities in Na/K pump current (IP), transient outward K+-current (Ito), and Ca2+-current (ICaL) play an important role in regulating electrical and contractile activities in the ventricular myocardium. Prior studies indicated angiotensin II (A2) may determine the transmural gradient in Ito, but the effects of A2 on IP and ICaL were unknown. In this study, myocytes were isolated from five muscle layers between epicardium and endocardium. We found a monotonic gradient in both Ip and Ito, with the lowest currents in ENDO. When AT1Rs were inhibited, EPI currents were unaffected, but ENDO currents increased, suggesting endogenous extracellular A2 inhibits both currents in ENDO. IP- and Ito-inhibition by A2 yielded essentially the same K0.5 values, so they may both be regulated by the same mechanism. A2/AT1R-mediated inhibition of IP or Ito or stimulation of ICaL persisted for hours in isolated myocytes, suggesting continuous autocrine secretion of A2 into a restricted diffusion compartment, like the T-system. Detubulation brought EPI IP to its low ENDO value and eliminated A2 sensitivity, so the T-system lumen may indeed be the restricted diffusion compartment. These studies showed that 33–50% of IP, 57–65% of Ito, and a significant fraction of ICaL reside in T-tubule membranes where they are transmurally regulated by autocrine secretion of A2 into the T-system lumen and activation of AT1Rs. Increased AT1R activation regulates each of these currents in a direction expected to increase contractility. Endogenous A2 activation of AT1Rs increases monotonically from EPI to ENDO in a manner similar to reported increases in passive tension when the ventricular chamber fills with blood. We therefore hypothesize load is the signal that regulates A2-activation of AT1Rs, which create a contractile gradient that matches the gradient in load. PMID:24896115

Autocrine-paracrine regulation of the mammary gland.

PubMed

Weaver, S R; Hernandez, L L

2016-01-01

The mammary gland has a remarkable capacity for regulation at a local level, particularly with respect to its main function: milk secretion. Regulation of milk synthesis has significant effects on animal and human health, at the level of both the mother and the neonate. Control by the mammary gland of its essential function, milk synthesis, is an evolutionary necessity and is therefore tightly regulated at a local level. For at least the last 60 yr, researchers have been interested in elucidating the mechanisms underpinning the mammary gland's ability to self-regulate, largely without the influence from systemic hormones or signals. By the 1960s, scientists realized the importance of milk removal in the capacity of the gland to produce milk and that the dynamics of this removal, including emptying of the alveolar spaces and frequency of milking, were controlled locally as opposed to traditional systemic hormonal regulation. Using both in vitro systems and various mammalian species, including goats, marsupials, humans, and dairy cows, it has been demonstrated that the mammary gland is largely self-regulating in its capacity to support the young, which is the evolutionary basis for milk production. Local control occurs at the level of the mammary epithelial cell through pressure and stretching negative-feedback mechanisms, and also in an autocrine fashion through bioactive factors within the milk which act as inhibitors, regulating milk secretion within the alveoli themselves. It is only within the last 20 to 30 yr that potential candidates for these bioactive factors have been examined at a molecular level. Several, including parathyroid hormone-related protein, growth factors (transforming growth factor, insulin-like growth factor, epidermal growth factor), and serotonin, are synthesized within and act upon the gland and possess dynamic receptor activity resulting in diverse effects on growth, calcium homeostasis, and milk composition. This review will focus on the autocrine-paracrine regulation of the mammary gland, with an examination of both foundational work and the progress made within the last 10 to 20 yr of research. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Constitutively active c-Met kinase in PC-3 cells is autocrine-independent and can be blocked by the Met kinase inhibitor BMS-777607

PubMed Central

2012-01-01

Background The c-Met receptor tyrosine kinase is aberrantly activated in many solid tumors. In a prior study we showed that prostate cancer PC-3 cells exhibit constitutively activated c-Met without exogenous hepatocyte growth factor (HGF); however whether this characteristic is due to an endogenous HGF/c-Met autocrine loop remains controversial. In the current study we examined the response of PC-3 cells to an anti-HGF neutralizing antibody or a small molecule Met kinase inhibitor (BMS-777607). Methods Cell scattering was tested by monitoring cell morphology after HGF stimulation. Cell migration was examined by both “wound-healing” and transwell assasy and invasion was detected by Matrigel-coated transwell assay. Proliferation, survival and anoikis were determined by MTT, colony formation and trypan blue exclusion assay, respectively. Gene and protein expression were assessed by real-time PCR and Western blot, respectively. Results Although HGF mRNA could be detected in PC-3 cells, the molecular weight of secreted “HGF” protein was inconsistent with the functional recombinant HGF. Furthermore, conditioned medium from PC-3 cell cultures was ineffective at triggering either motogenic behavior or c-Met signaling in DU145, another prostate cancer cell line expressing c-Met but lacking basal c-Met activation. PC-3 cells also were not responsive to the anti-HGF neutralizing antibody in experiments assessing proliferation, migration, or c-Met signaling. BMS-777607 treatment with micromolar doses nonetheless led to significant inhibition of multiple PC-3 cell functions including proliferation, clonogenicity, migration and invasion. At the molecular level, BMS-777607 suppressed autophosphorylated c-Met and downstream c-Src and Akt pathways. Conclusions These results suggest that the constitutive c-Met activation in PC-3 is independent of autocrine stimulation. Because PC-3 cells were responsive to BMS-777607 but not the anti-HGF antibody, the findings also indicate that under circumstances where c-Met is constitutively hyperactive in the absence of functional HGF, targeting the c-Met receptor remains a viable therapeutic option to impede cancer progression. PMID:22639908

Role of the TGF-Beta 1 in the Prevention of Prostate Cancer

DTIC Science & Technology

2001-04-01

the prostate or seminal vesicles delayed tumor development in the TRAMP mice through autocrine and paracrine pathways. 14. SUBJECT TERMS 15. NUMBER OF...it imperative to develop prevention strategies against this disease. Modifications in environmental, dietary, endocrine, or genetic factors may play a...This hypothesis is being tested in TRAMP transgenic mice, which develop spontaneous prostate cancer with features similar to that of human prostate

Kinin-B2 receptor expression and activity during differentiation of embryonic rat neurospheres.

PubMed

Martins, Antonio H; Alves, Janaína M; Trujillo, Cleber A; Schwindt, Telma T; Barnabé, Gabriela F; Motta, Fabiana L T; Guimaraes, Alessander O; Casarini, Dulce E; Mello, Luiz E; Pesquero, João B; Ulrich, Henning

2008-04-01

Neural progenitor cells were isolated from rat fetal telencephalon and proliferate as neurospheres in the presence of EGF, FGF-2, and heparin. In the absence of these growth factors, neurospheres differentiate into neurons, astrocytes, and oligodendrocytes. Using an embryonal carcinoma cell line as in vitro differentiation model, we have already demonstrated the presence of an autocrine loop system between kinin-B2 receptor activity and secretion of its ligand bradykinin (BK) as prerequisites for final neuronal differentiation (Martins et al., J Biol Chem 2005; 280: 19576-19586). The aim of this study was to verify the activity of the kallikrein-kinin system (KKS) during neural progenitor cell differentiation. Immunofluorescence studies and flow cytometry analysis revealed increases in glial fibrillary acidic protein and beta-3 tubulin expression and decrease in the number of nestin-positive cells along neurospheres differentiation, indicating the transition of neural progenitor cells to astrocytes and neurons. Kinin-B2 receptor expression and activity, secretion of BK into the medium, and presence of high-molecular weight kininogen suggest the participation of the KKS in neurosphere differentiation. Functional kinin-B2 receptors and BK secretion indicate an autocrine loop during neurosphere differentiation to neurons, astrocytes, and oligodendrocytes, reflecting events occurring during early brain development. (c) 2008 International Society for Analytical Cytology.

Vascular endothelial growth factor and the kidney: something of the marvellous.

PubMed

Advani, Andrew

2014-01-01

The vascular endothelial growth factor (VEGF) system is a multifarious network and an exemplar of an intraglomerular signalling pathway. Here, we review recent advances that highlight the subtle nature of the renal VEGF system and its influencers. The VEGF system is no longer considered as a simple paracrine, ligand-receptor interaction under the regulatory control of a soluble 'decoy', soluble fms-like tyrosine kinase-1 (sFLT1). Rather, the abundantly expressed, podocyte-derived VEGF isoform, VEGF-A, is now recognized to mediate both paracrine effects across the filtration barrier and autocrine actions, functioning to preserve the integrity of the cells from which it arises. Autocrine actions of the podocyte VEGF system extend beyond those of the VEGF-A isoform, however, with sFLT1 itself now appreciated as regulating podocyte morphology by binding to lipid microdomains. These and other functions of the VEGF system are profoundly affected by the presence, nature and abundance of influencers both intrinsic and extrinsic to the pathway, the latter most readily exemplified by the role of the cytokine in the diabetic kidney. The glomerular VEGF system plays a delicate, yet critical, role in preserving renal homeostasis. It may be intricate, but 'in all things of nature there is something of the marvellous'.

Autocrine prostaglandin E2 signaling promotes promonocytic leukemia cell survival via COX-2 expression and MAPK pathway

PubMed Central

Lee, Jaetae; Lee, Young Sup

2015-01-01

The COX-2/PGE2 pathway has been implicated in the occurrence and progression of cancer. The underlying mechanisms facilitating the production of COX-2 and its mediator, PGE2, in cancer survival remain unknown. Herein, we investigated PGE2-induced COX-2 expression and signaling in HL-60 cells following menadione treatment. Treatment with PGE2 activated anti-apoptotic proteins such as Bcl-2 and Bcl-xL while reducing pro-apoptotic proteins, thereby enhancing cell survival. PGE2 not only induced COX-2 expression, but also prevented casapse-3, PARP, and lamin B cleavage. Silencing and inhibition of COX-2 with siRNA transfection or treatment with indomethacin led to a pronounced reduction of the extracellular levels of PGE2, and restored the menadione-induced cell death. In addition, pretreatment of cells with the MEK inhibitor PD98059 and the PKA inhibitor H89 abrogated the PGE2-induced expression of COX-2, suggesting involvement of the MAPK and PKA pathways. These results demonstrate that PGE2 signaling acts in an autocrine manner, and specific inhibition of PGE2 will provide a novel approach for the treatment of leukemia. [BMB Reports 2015; 48(2): 109-114] PMID:24965577

IL-17 Production of Neutrophils Enhances Antibacteria Ability but Promotes Arthritis Development During Mycobacterium tuberculosis Infection.

PubMed

Hu, Shengfeng; He, Wenting; Du, Xialin; Yang, Jiahui; Wen, Qian; Zhong, Xiao-Ping; Ma, Li

2017-09-01

To our knowledge, no studies have examined the role of IL-17 production by neutrophils in immune defense against Mycobacterium tuberculosis (MTB) infection and the pathogenesis of rheumatoid arthritis (RA) caused by MTB infection. Here, we determined that neutrophils express IL-17 in an autocrine IL-6- and IL-23-dependent manner during MTB infection. MTB H37Rv-induced IL-6 production was dependent on the NF-κB, p38, and JNK signaling pathways; however, IL-23 production was dependent on NF-κB and EKR in neutrophils. Furthermore, we found that Toll-like receptor 2 (TLR2) and TLR4 mediated the activation of the kinases NF-κB, p38, ERK, and JNK and the production of IL-6, IL-23, and IL-17 in neutrophils infected with MTB H37Rv. Autocrine IL-17 produced by neutrophils played a vital role in inhibiting MTB H37Rv growth by mediating reactive oxygen species production and the migration of neutrophils in the early stages of infection. However, IL-17 production by neutrophils contributed to collagen-induced arthritis development during MTB infection. Our findings identify a protective mechanism against mycobacteria and the pathogenic role of MTB in arthritis development. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Role for Heat Shock Protein 90α in the Proliferation and Migration of HaCaT Cells and in the Deep Second-Degree Burn Wound Healing in Mice

PubMed Central

Li, Na; Li, Xiaoqiang; Han, Fei; Su, Linlin; Hu, Dahai

2014-01-01

Inflammation, proliferation, and tissue remodeling are essential steps for wound healing. The hypoxic wound microenvironment promotes cell migration through a hypoxia—heat shock protein 90 alpha (Hsp90α)—low density lipoprotein receptor-related protein-1 (LRP-1) autocrine loop. To elucidate the role of this autocrine loop on burn wound healing, we investigated the expression profile of Hsp90α at the edge of burn wounds and found a transient increase in both mRNA and protein levels. Experiments performed with a human keratinocyte cell line—HaCaT also confirmed above results. 17-dimethylaminoethylamino-17demethoxygeldanamycin hydrochloride (17-DMAG), an Hsp90α inhibitor, was used to further evaluate the function of Hsp90α in wound healing. Consistently, topical application of Hsp90α in the early stage of deep second-degree burn wounds led to reduced inflammation and increased tissue granulation, with a concomitant reduction in the size of the wound at each time point tested (p<0.05). Consequently, epidermal cells at the wound margin progressed more rapidly causing an expedited healing process. In conclusion, these results provided a rationale for the therapeutic effect of Hsp90α on the burn wound management. PMID:25111496

Salinity and temperature variations reflecting on cellular PCNA, IGF-I and II expressions, body growth and muscle cellularity of a freshwater fish larvae.

PubMed

Martins, Y S; Melo, R M C; Campos-Junior, P H A; Santos, J C E; Luz, R K; Rizzo, E; Bazzoli, N

2014-06-01

The present study assessed the influence of salinity and temperature on body growth and on muscle cellularity of Lophiosilurus alexaxdri vitelinic larvae. Slightly salted environments negatively influenced body growth of freshwater fish larvae and we observed that those conditions notably act as an environmental influencer on muscle growth and on local expression of hypertrophia and hypeplasia markers (IGFs and PCNA). Furthermore, we could see that salinity tolerance for NaCl 4gl(-)(1) diminishes with increasing temperature, evidenced by variation in body and muscle growth, and by irregular morphology of the lateral skeletal muscle of larvae. We saw that an increase of both PCNA and autocrine IGF-II are correlated to an increase in fibre numbers and fibre diameter as the temperature increases and salinity diminishes. On the other hand, autocrine IGF-I follows the opposite way to the other biological parameters assessed, increasing as salinity increases and temperature diminishes, showing that this protein did not participate in muscle cellularity, but participating in molecular/cellular repair. Therefore, slightly salted environments may provide adverse conditions that cause some obstacles to somatic growth of this species, suggesting some osmotic expenditure with a salinity increment. Copyright © 2014 Elsevier Inc. All rights reserved.

Autocrine CSF-1 and CSF-1 Receptor Co-expression Promotes Renal Cell Carcinoma Growth

PubMed Central

Menke, Julia; Kriegsmann, Jörg; Schimanski, Carl Christoph; Schwartz, Melvin M.; Schwarting, Andreas; Kelley, Vicki R.

2011-01-01

Renal cell carcinoma is increasing in incidence but the molecular mechanisms regulating its growth remain elusive. Co-expression of the monocytic growth factor CSF-1 and its receptor CSF-1R on renal tubular epithelial cells (TEC) will promote proliferation and anti-apoptosis during regeneration of renal tubules. Here we show that a CSF-1-dependent autocrine pathway is also responsible for the growth of renal cell carcinoma (RCC). CSF-1 and CSF-1R were co-expressed in RCC and TEC proximally adjacent to RCC. CSF-1 engagement of CSF-1R promoted RCC survival and proliferation and reduced apoptosis, in support of the likelihood that CSF-1R effector signals mediate RCC growth. In vivo CSF-1R blockade using a CSF-1R tyrosine kinase inhibitor decreased RCC proliferation and macrophage infiltration in a manner associated with a dramatic reduction in tumor mass. Further mechanistic investigations linked CSF-1 and EGF signaling in RCC. Taken together, our results suggest that budding RCC stimulates the proximal adjacent microenvironment in the kidney to release mediators of CSF-1, CSF-1R and EGF expression in RCC. Further, our findings imply that targeting CSF-1/CSF-1R signaling may be therapeutically effective in RCC. PMID:22052465

3,3′-Diindolylmethane stimulates exosomal Wnt11 autocrine signaling in human umbilical cord mesenchymal stem cells to enhance wound healing

PubMed Central

Shi, Hui; Xu, Xiao; Zhang, Bin; Xu, Jiahao; Pan, Zhaoji; Gong, Aihua; Zhang, Xu; Li, Rong; Sun, Yaoxiang; Yan, Yongmin; Mao, Fei; Qian, Hui; Xu, Wenrong

2017-01-01

Human umbilical cord-derived mesenchymal stem cells (hucMSCs) are suggested as a promising therapeutic tool in regenerative medicine, however, their efficacy requires improvement. Small molecules and drugs come up to be a convenient strategy in regulating stem cells fate and function. Here, we evaluated 3,3′-diindolylmethane (DIM), a natural small-molecule compound involved in the repairing effects of hucMSCs on a deep second-degree burn injury rat model. HucMSCs primed with 50 μM of DIM exhibited desirable repairing effects compared with untreated hucMSCs. DIM enhanced the stemness of hucMSCs, which was related to the activation of Wnt/β-catenin signaling. β-catenin inhibition impaired the healing effects of DIM-primed hucMSCs (DIM-hucMSCs) in vivo. Moreover, we demonstrated that DIM upregulated Wnt11 expression in hucMSC-derived exosomes. Wnt11 knockdown inhibited β-catenin activation and stemness induction in DIM-hucMSCs and abrogated their therapeutic effects in vivo. Thus, our findings indicate that DIM promotes the stemness of hucMSCs through increased exosomal Wnt11 autocrine signaling, which provides a novel strategy for improving the therapeutic effects of hucMSCs on wound healing. PMID:28529644

Activation of the protein-tyrosine kinase associated with the bombesin receptor complex in small cell lung carcinomas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaudino, G.; Cirillo, D.; Naldini, L.

1988-04-01

It has been hypothesized that bombesin-like peptides produced by small cell lung carcinomas may sustain deregulated proliferation through an autocrine mechanism. The authors have shown that the neuropeptide bombesin leads to the activation of a protein-tyrosine kinase that phosphorylates a 115-kDa protein (p115) associated with the bombesin receptor complex in mouse Swiss 3T3 fibroblasts. They now report that phosphotyrosine antibodies recognize a 115-kDa protein, phosphorylated on tyrosine, in four human small cell lung carcinoma cell lines producing bombesin but not in a nonproducer variant line. p115 from detergent-treated small cell lung carcinoma cells binds to bombesin-Sepharose and can be phosphorylatedmore » on tyrosine in the presence of radiolabeled ATP and Mn{sup 2+}. As for the p115 immunoprecipitated from mouse fibroblast, the small cell lung carcinoma p115 can be phosphorylated in an immunocomplex kinase assay. However, the latter does not require the presence of exogenous bombesin for activity. Binding data, obtained by using radiolabeled ligand, suggest receptor occupancy in the cell lines producing bombesin. These observations are consistent with the hypothesis that proliferation in some human small cell lung carcinoma lines is under autocrine control, regulated through activation of bombesin receptors.« less

Melanoma cell-derived exosomes promote epithelial-mesenchymal transition in primary melanocytes through paracrine/autocrine signaling in the tumor microenvironment

PubMed Central

Xiao, Deyi; Barry, Samantha; Kmetz, Daniel; Egger, Michael; Pan, Jianmin; Rai, Shesh N; Qu, Jifu; McMasters, Kelly M.; Hao, Hongying

2016-01-01

The tumor microenvironment is abundant with exosomes that are secreted by the cancer cells themselves. Exosomes are nanosized, organelle-like membranous structures that are increasingly being recognized as major contributors in the progression of malignant neoplasms. A critical element in melanoma progression is its propensity to metastasize, but little is known about how melanoma cell-derived exosomes modulate the microenvironment to optimize conditions for tumor progression and metastasis. Here, we provide evidence that melanoma cell-derived exosomes promote phenotype switching in primary melanocytes through paracrine/autocrine signaling. We found that the mitogen-activated protein kinase (MAPK) signaling pathway was activated during the exosome-mediated epithelial-to-mesenchymal transition (EMT)-resembling process, which promotes metastasis. Let-7i, an miRNA modulator of EMT, was also involved in this process. We further defined two other miRNA modulators of EMT (miR-191 and let-7a) in serum exosomes for differentiating stage I melanoma patients from non-melanoma subjects. These results provide the first strong molecular evidence that melanoma cell-derived exosomes promote the EMT-resembling process in the tumor microenvironment. Thus, novel strategies targeting EMT and modulating the tumor microenvironment may emerge as important approaches for the treatment of metastatic melanoma. PMID:27063098

Myostatin inhibits proliferation of human urethral rhabdosphincter satellite cells.

PubMed

Akita, Yasuyuki; Sumino, Yasuhiro; Mori, Ken-ichi; Nomura, Takeo; Sato, Fuminori; Mimata, Hiromitsu

2013-05-01

Myostatin, a member of the transforming growth factor-β superfamily, is a negative regulator of myogenesis in skeletal muscle. We examined the effect of myostatin and myostatin inhibition by an antagonistic agent, follistatin, on growth of human urethral rhabdosphincter satellite cells (muscle stem cells) to develop a new strategy for treatment of stress urinary incontinence. Rhabdosphincter satellite cells were cultured and selected by magnetic affinity cell sorting using an anti-neural cell adhesion molecule antibody. The cells were transfected with simian virus-40 antigen to extend their lifespan. A cell proliferation assay, a cell cycle analysis and an investigation of signal transduction were carried out. The autocrine action of endogenous myostatin by western blotting, real-time reverse transcription polymerase chain reaction and immunoneutralization using an anti-myostatin antibody was also evaluated. Selectively cultured cells expressed markers of striated muscles and successfully differentiated into myotubes. Myostatin inhibited proliferation of these cells through Smad2 phosphorylation and cell cycle arrest. Inhibitory effects of myostatin were reversed by addition of follistatin. However, rhabdosphincter satellite cells did not appear to use autocrine secretion of myostatin to regulate their proliferation. Inhibition of myostatin function might be a useful pathway in the development of novel strategies for stimulating rhabdosphincter cells regeneration to treat stress urinary incontinence. © 2012 The Japanese Urological Association.

Lipocalin 2 functions as a negative regulator of red blood cell production in an autocrine fashion.

PubMed

Miharada, Ken-ichi; Hiroyama, Takashi; Sudo, Kazuhiro; Nagasawa, Toshiro; Nakamura, Yukio

2005-11-01

Members of the lipocalin protein family are typically small, secreted proteins that possess a variety of functions. Although the physiological role of lipocalin 2 remains to be fully elucidated, a few pivotal functions have recently been reported, e.g., regulation of the apoptosis of leukocytes. Unexpectedly, lipocalin 2 is abundantly expressed in erythroid progenitor cells. An in vitro culture experiment demonstrated that lipocalin 2 induces apoptosis and inhibits differentiation of erythroid progenitor cells. During acute anemia the expression of lipocalin 2 was reduced in erythroid cells by a feedback system. Furthermore, injection of recombinant lipocalin 2 into mice suffering from acute anemia retarded the recovery of red blood cell (RBC) numbers, suggesting the importance of reduced expression of lipocalin 2 for the efficient recovery of RBC numbers. These results indicate that lipocalin 2 suppresses RBC production in an autocrine fashion. Hence, anemia arising from pathological conditions, such as chronic inflammation, might be partly due to increased levels of lipocalin 2 secreted from expanded leukocytes and/or macrophages. Also, anemia arising from malignancies might be partly due to the abundant secretion of lipocalin 2 from tumor cells. Thus, lipocalin 2 may represent an attractive therapeutic target for anemia under certain pathological conditions.

Extracellular Hsp70 Enhances Mesoangioblast Migration via an Autocrine Signaling Pathway.

PubMed

Barreca, Maria M; Spinello, Walter; Cavalieri, Vincenzo; Turturici, Giuseppina; Sconzo, Gabriella; Kaur, Punit; Tinnirello, Rosaria; Asea, Alexzander A A; Geraci, Fabiana

2017-07-01

Mouse mesoangioblasts are vessel-associated progenitor stem cells endowed with the ability of multipotent mesoderm differentiation. Therefore, they represent a promising tool in the regeneration of injured tissues. Several studies have demonstrated that homing of mesoangioblasts into blood and injured tissues are mainly controlled by cytokines/chemokines and other inflammatory factors. However, little is known about the molecular mechanisms regulating their ability to traverse the extracellular matrix (ECM). Here, we demonstrate that membrane vesicles released by mesoangioblasts contain Hsp70, and that the released Hsp70 is able to interact by an autocrine mechanism with Toll-like receptor 4 (TLR4) and CD91 to stimulate migration. We further demonstrate that Hsp70 has a positive role in regulating matrix metalloproteinase 2 (MMP2) and MMP9 expression and that MMP2 has a more pronounced effect on cell migration, as compared to MMP9. In addition, the analysis of the intracellular pathways implicated in Hsp70 regulated signal transduction showed the involvement of both PI3K/AKT and NF-κB. Taken together, our findings present a paradigm shift in our understanding of the molecular mechanisms that regulate mesoangioblast stem cells ability to traverse the extracellular matrix (ECM). J. Cell. Physiol. 232: 1845-1861, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Autocrine release of angiopoietin-2 mediates cerebrovascular disintegration in Moyamoya disease

PubMed Central

Blecharz, Kinga G; Frey, Dietmar; Schenkel, Tobias; Prinz, Vincent; Bedini, Gloria; Krug, Susanne M; Czabanka, Marcus; Wagner, Josephin; Fromm, Michael; Bersano, Anna

2016-01-01

Moyamoya disease is a rare steno-occlusive cerebrovascular disorder often resulting in hemorrhagic and ischemic strokes. Although sharing the same ischemic stimulus with atherosclerotic cerebrovascular disease, Moyamoya disease is characterized by a highly instable cerebrovascular system which is prone to rupture due to pathological neovascularization. To understand the molecular mechanisms underlying this instability, angiopoietin-2 gene expression was analyzed in middle cerebral artery lesions obtained from Moyamoya disease and atherosclerotic cerebrovascular disease patients. Angiopoietin-2 was significantly up-regulated in Moyamoya vessels, while serum concentrations of soluble angiopoietins were not changed. For further evaluations, cerebral endothelial cells incubated with serum from these patients in vitro were applied. In contrast to atherosclerotic cerebrovascular disease serum, Moyamoya disease serum induced an angiopoietin-2 overexpression and secretion, accompanied by loss of endothelial integrity. These effects were absent or inverse in endothelial cells of non-brain origin suggesting brain endothelium specificity. The destabilizing effects on brain endothelial cells to Moyamoya disease serum were partially suppressed by the inhibition of angiopoietin-2. Our findings define brain endothelial cells as the potential source of vessel-destabilizing factors inducing the high plasticity state and disintegration in Moyamoya disease in an autocrine manner. We also provide new insights into Moyamoya disease pathophysiology that may be helpful for preventive treatment strategies in future. PMID:27381827

Differential endothelial transcriptomics identifies semaphorin 3G as a vascular class 3 semaphorin.

PubMed

Kutschera, Simone; Weber, Holger; Weick, Anja; De Smet, Frederik; Genove, Guillem; Takemoto, Minoru; Prahst, Claudia; Riedel, Maria; Mikelis, Constantinos; Baulande, Sylvain; Champseix, Catherine; Kummerer, Petra; Conseiller, Emmanuel; Multon, Marie-Christine; Heroult, Melanie; Bicknell, Roy; Carmeliet, Peter; Betsholtz, Christer; Augustin, Hellmut G

2011-01-01

To characterize the role of a vascular-expressed class 3 semaphorin (semaphorin 3G [Sema3G]). Semaphorins have been identified as axon guidance molecules. Yet, they have more recently also been characterized as attractive and repulsive regulators of angiogenesis. Through a transcriptomic screen, we identified Sema3G as a molecule of angiogenic endothelial cells. Sema3G-deficient mice are viable and exhibit no overt vascular phenotype. Yet, LacZ expression in the Sema3G locus revealed intense arterial vascular staining in the angiogenic vasculature, starting at E9.5, which was detectable throughout adolescence and downregulated in adult vasculature. Sema3G is expressed as a full-length 100-kDa secreted molecule that is processed by furin proteases to yield 95- and a 65-kDa Sema domain-containing subunits. Full-length Sema3G binds to NP2, whereas processed Sema3G binds to NP1 and NP2. Expression profiling and cellular experiments identified autocrine effects of Sema3G on endothelial cells and paracrine effects on smooth muscle cells. Although the mouse knockout phenotype suggests compensatory mechanisms, the experiments identify Sema3G as a primarily endothelial cell-expressed class 3 semaphorin that controls endothelial and smooth muscle cell functions in autocrine and paracrine manners, respectively.

The Functional Effect of an Amphiregulin Autocrine Loop on Inflammatory Breast Cancer Progression

DTIC Science & Technology

2008-03-01

Darby canine kidney cells (15). Also, using targeted knockout mice, Luetteke et al. reported that specific loss of AR, but not EGF or TGF-a, severely...due to relocalization of E-cadherin in Madin-Darby canine kidney cells (15). Our laboratory has also discovered that AR signaling differs from EGF...growth factor induction of matrix metalloproteinases and their inhibitors in osteosarcoma cells is modulated by the metastasis associated protein CAPL

Concise Review: Multifaceted Characterization of Human Mesenchymal Stem Cells for Use in Regenerative Medicine.

PubMed

Samsonraj, Rebekah M; Raghunath, Michael; Nurcombe, Victor; Hui, James H; van Wijnen, Andre J; Cool, Simon M

2017-12-01

Mesenchymal stem cells (MSC) hold great potential for regenerative medicine because of their ability for self-renewal and differentiation into tissue-specific cells such as osteoblasts, chondrocytes, and adipocytes. MSCs orchestrate tissue development, maintenance and repair, and are useful for musculoskeletal regenerative therapies to treat age-related orthopedic degenerative diseases and other clinical conditions. Importantly, MSCs produce secretory factors that play critical roles in tissue repair that support both engraftment and trophic functions (autocrine and paracrine). The development of uniform protocols for both preparation and characterization of MSCs, including standardized functional assays for evaluation of their biological potential, are critical factors contributing to their clinical utility. Quality control and release criteria for MSCs should include cell surface markers, differentiation potential, and other essential cell parameters. For example, cell surface marker profiles (surfactome), bone-forming capacities in ectopic and orthotopic models, as well as cell size and granularity, telomere length, senescence status, trophic factor secretion (secretome), and immunomodulation, should be thoroughly assessed to predict MSC utility for regenerative medicine. We propose that these and other functionalities of MSCs should be characterized prior to use in clinical applications as part of comprehensive and uniform guidelines and release criteria for their clinical-grade production to achieve predictably favorable treatment outcomes for stem cell therapy. Stem Cells Translational Medicine 2017;6:2173-2185. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Autocrine stimulation of osteoblast activity by Wnt5a in response to TNF-α in human mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Briolay, A.; Lencel, P.; Bessueille, L.

2013-01-18

Highlights: ► Ankylosing spondylitis (AS) leads to bone fusions and ankylosis. ► TNF-α stimulates osteoblasts through growth factors in AS. ► We compare the involvement of canonical vs non-canonical Wnt signaling. ► Canonical Wnt signaling is not involved in TNF-α effects in differentiating hMSCs. ► TNF-α stimulates osteoblasts through Wnt5a autocrine secretion in hMSCs. -- Abstract: Although anti-tumor necrosis factor (TNF)-α treatments efficiently block inflammation in ankylosing spondylitis (AS), they are inefficient to prevent excessive bone formation. In AS, ossification seems more prone to develop in sites where inflammation has resolved following anti-TNF therapy, suggesting that TNF-α indirectly stimulates ossification.more » In this context, our objectives were to determine and compare the involvement of Wnt proteins, which are potent growth factors of bone formation, in the effects of TNF-α on osteoblast function. In human mesenchymal stem cells (MSCs), TNF-α significantly increased the levels of Wnt10b and Wnt5a. Associated with this effect, TNF-α stimulated tissue-non specific alkaline phosphatase (TNAP) and mineralization. This effect was mimicked by activation of the canonical β-catenin pathway with either anti-Dkk1 antibodies, lithium chloride (LiCl) or SB216763. TNF-α reduced, and activation of β-catenin had little effect on expression of osteocalcin, a late marker of osteoblast differentiation. Surprisingly, TNF-α failed to stabilize β-catenin and Dkk1 did not inhibit TNF-α effects. In fact, Dkk1 expression was also enhanced in response to TNF-α, perhaps explaining why canonical signaling by Wnt10b was not activated by TNF-α. However, we found that Wnt5a also stimulated TNAP in MSCs cultured in osteogenic conditions, and increased the levels of inflammatory markers such as COX-2. Interestingly, treatment with anti-Wnt5a antibodies reduced endogenous TNAP expression and activity. Collectively, these data suggest that increased levels of Dkk1 may blunt the autocrine effects of Wnt10b, but not that of Wnt5a, acting through non-canonical signaling. Thus, Wnt5a may be potentially involved in the effects of inflammation on bone formation.« less

Paracrine and autocrine signals promoting full chondrogenic differentiation of a mesoblastic cell line.

PubMed

Locker, Morgane; Kellermann, Odile; Boucquey, Marie; Khun, Huot; Huerre, Michel; Poliard, Anne

2004-01-01

The pluripotent mesoblastic C1 cell line was used under serum-free culture conditions to investigate how paracrine and autocrine signals cooperate to drive chondrogenesis. Sequential addition of two systemic hormones, dexamethasone and triiodothyronine, permits full chondrogenic differentiation. The cell intrinsic activation of the BMP signaling pathway and Sox9 expression occurring on mesoblastic condensation is insufficient for recruitment of the progenitors. Dexamethasone-dependent Sox9 upregulation is essential for chondrogenesis. Differentiation of lineage stem cells relies on cell autonomous regulations modulated by external signals. We used the pluripotent mesoblastic C1 cell line under serum-free culture conditions to investigate how paracrine and autocrine signals cooperate to induce differentiation of a precursor clone along the chondrogenic lineage. C1 cells, cultured as aggregates, were induced toward chondrogenesis by addition of 10(-7) M dexamethasone in serum-free medium. After 30 days, dexamethasone was replaced by 10 nM triiodothyronine to promote final hypertrophic conversion. Mature and hypertrophic phenotypes were characterized by immunocytochemistry using specific antibodies against types II and X collagens, respectively. Type II collagen, bone morphogenetic proteins (BMPs), BMP receptors, Smads, and Sox9 expression were monitored by reverse transcriptase-polymerase chain reaction (RT-PCR), Northern blot, and/or Western blot analysis. Once C1 cells have formed nodules, sequential addition of two systemic hormones is sufficient to promote full chondrogenic differentiation. In response to dexamethasone, nearly 100% of the C1 precursors engage in chondrogenesis and convert within 30 days into mature chondrocytes, which triggers a typical cartilage matrix. On day 25, a switch in type II procollagen mRNA splicing acted as a limiting step in the acquisition of the mature chondrocyte phenotype. On day 30, substitution of dexamethasone with triiodothyronine triggers the final differentiation into hypertrophic chondrocytes within a further 15 days. The chondrogenic process is supported by intrinsic expression of Sox9 and BMP family genes. Similarly to the in vivo situation, activation of Sox9 expression and the BMP signaling pathway occurred on mesoblastic condensation. After induction, BMP-activated Smad nuclear translocation persisted throughout the process until the onset of hypertrophy. After dexamethasone addition, Sox9 expression was upregulated. Dexamethasone withdrawal reversed the increase in Sox9 expression and stopped differentiation. Thus, Sox9 seems to be a downstream mediator of dexamethasone action.

Potential Prognostic Markers for Human Prostate Cancer

DTIC Science & Technology

2001-03-01

thymosin 0315 gene. The gene appears to exist as a single copy in the rat genome and is comprised of 3 exons distributed over 3 kilobases. The...metastatic prostate cancer cells. Autocrine motility factor ( AMF ), a prostate tumor G low low cell secreted factor [13], also affects motility of...prostate H low low carcinoma cells. Tumor cell migration in response to HIF low low ATI low low AMF has been associated with metastatic potential. AT2 low

Transforming Growth Factor Beta Signaling in Growth of Estrogen-Insensitive Metastatic Bone Lesions

DTIC Science & Technology

2012-01-01

survival [12]. These observations suggest that more aggressive basal- like breast cancers have the capacity to be stimulated by autocrine EGFR...EGF, and AREG, as well as Normal Goat IgG, were purchased from R&D Systems (Minneapolis, MN). PAR34 clone was a gift from PDL BioPharma , and was...found that many of the subclones had differing capacities to colonize various organs after intracardiac injection into mice (12, 119-123). Gene

Endothelial microparticles: Sophisticated vesicles modulating vascular function

PubMed Central

Curtis, Anne M; Edelberg, Jay; Jonas, Rebecca; Rogers, Wade T; Moore, Jonni S; Syed, Wajihuddin; Mohler, Emile R

2015-01-01

Endothelial microparticles (EMPs) belong to a family of extracellular vesicles that are dynamic, mobile, biological effectors capable of mediating vascular physiology and function. The release of EMPs can impart autocrine and paracrine effects on target cells through surface interaction, cellular fusion, and, possibly, the delivery of intra-vesicular cargo. A greater understanding of the formation, composition, and function of EMPs will broaden our understanding of endothelial communication and may expose new pathways amenable for therapeutic manipulation. PMID:23892447

The Role of Autocrine-Paracrine Cascades in Breast Tumor Metastasis

DTIC Science & Technology

1999-08-01

tested a large series of anti-oxidants at non- toxic doses. The only compounds that worked in this series were resveratrol and curcumin . The...resveratrol gave a 20-35% maximal inhibition while the curcumin gave a maximal response between 40 and 60% maximal inhibition. While the resveratrol inhibited...IL-8 expression in both -7- THIS REPORT CONTAINS PROPRIETARY AND/OR UNPUBLISHED DATA the MD-231 and MD-435s cells, the inhibitory effects of curcumin

Autocrine stimulation of VEGFR-2 activates human leukemic cell growth and migration

PubMed Central

Dias, Sergio; Hattori, Koichi; Zhu, Zhenping; Heissig, Beate; Choy, Margaret; Lane, William; Wu, Yan; Chadburn, Amy; Hyjek, Elizabeth; Gill, Muhammad; Hicklin, Daniel J.; Witte, Larry; Moore, M.A.S.; Rafii, Shahin

2000-01-01

Emerging data suggest that VEGF receptors are expressed by endothelial cells as well as hematopoietic stem cells. Therefore, we hypothesized that functional VEGF receptors may also be expressed in malignant counterparts of hematopoietic stem cells such as leukemias. We demonstrate that certain leukemias not only produce VEGF but also express functional VEGFR-2 in vivo and in vitro, resulting in the generation of an autocrine loop that may support leukemic cell survival and proliferation. Approximately 50% of freshly isolated leukemias expressed mRNA and protein for VEGFR-2. VEGF165 induced phosphorylation of VEGFR-2 and increased proliferation of leukemic cells, demonstrating these receptors were functional. VEGF165 also induced the expression of MMP-9 by leukemic cells and promoted their migration through reconstituted basement membrane. The neutralizing mAb IMC-1C11, specific to human VEGFR-2, inhibited leukemic cell survival in vitro and blocked VEGF165-mediated proliferation of leukemic cells and VEGF-induced leukemic cell migration. Xenotransplantation of primary leukemias and leukemic cell lines into immunocompromised nonobese diabetic mice resulted in significant elevation of human, but not murine, VEGF in plasma and death of inoculated mice within 3 weeks. Injection of IMC-1C11 inhibited proliferation of xenotransplanted human leukemias and significantly increased the survival of inoculated mice. Interruption of signaling by VEGFRs, particularly VEGFR-2, may provide a novel strategy for inhibiting leukemic cell proliferation. PMID:10953026

Epithelial cell kinase-B61: an autocrine loop modulating intestinal epithelial migration and barrier function.

PubMed

Rosenberg, I M; Göke, M; Kanai, M; Reinecker, H C; Podolsky, D K

1997-10-01

Epithelial cell kinase (Eck) is a member of a large family of receptor tyrosine kinases whose functions remain largely unknown. Expression and regulation of Eck and its cognate ligand B61 were analyzed in the human colonic adenocarcinoma cell line Caco-2. Immunocytochemical staining demonstrated coexpression of Eck and B61 in the same cells, suggestive of an autocrine loop. Eck levels were maximal in preconfluent cells. In contrast, B61 levels were barely detectable in preconfluent cells and increased progressively after the cells reached confluence. Caco-2 cells cultured in the presence of added B61 showed a significant reduction in the levels of dipeptidyl peptidase and sucrase-isomaltase mRNA, markers of Caco-2 cell differentiation. Cytokines interleukin-1beta (IL-1beta), basic fibroblast growth factor, IL-2, epidermal growth factor, and transforming growth factor-beta modulated steady-state levels of Eck and B61 mRNA and regulated Eck activation as assessed by tyrosine phosphorylation. Functionally, stimulation of Eck by B61 resulted in increased proliferation, enhanced barrier function, and enhanced restitution of injured epithelial monolayers. These results suggest that the Eck-B61 interaction, a target of regulatory peptides, plays a role in intestinal epithelial cell development, migration, and barrier function, contributing to homeostasis and preservation of continuity of the epithelial barrier.

STAT6 deficiency ameliorates Graves' disease severity by suppressing thyroid epithelial cell hyperplasia.

PubMed

Jiang, Xuechao; Zha, Bingbing; Liu, Xiaoming; Liu, Ronghua; Liu, Jun; Huang, Enyu; Qian, Tingting; Liu, Jiajing; Wang, Zhiming; Zhang, Dan; Wang, Luman; Chu, Yiwei

2016-12-01

Signal transducer and activator of transcription 6 (STAT6) is involved in epithelial cell growth. However, little is known regarding the STAT6 phosphorylation status in Graves' disease (GD) and its role in thyroid epithelial cells (TECs). In this study, we found that STAT6 phosphorylation (p-STAT6) was significantly increased in TECs from both GD patients and experimental autoimmune Graves' disease mice and that STAT6 deficiency ameliorated GD symptoms. Autocrine IL-4 signalling in TECs activated the phosphorylation of STAT6 via IL-4 R engagement, and the downstream targets of STAT6 were Bcl-xL and cyclin D1. Thus, the IL-4-STAT6-Bcl-xL/cyclin D1 pathway is crucial for TEC hyperplasia, which aggravates GD. More importantly, in vitro and in vivo experiments demonstrated that STAT6 phosphorylation inhibited by AS1517499 decreased TEC hyperplasia, thereby reducing serum T3 and T4 and ameliorating GD. Thus, our study reveals that in addition to the traditional pathogenesis of GD, in which autoantibody TRAb stimulates thyroid-stimulating hormone receptors and consequently produces T3, T4, TRAb could also trigger TECs producing IL-4, and IL-4 then acts in an autocrine manner to activate p-STAT6 signalling and stimulate unrestricted cell growth, thus aggravating GD. These findings suggest that STAT6 inhibitors could be potent therapeutics for treating GD.

STAT6 deficiency ameliorates Graves' disease severity by suppressing thyroid epithelial cell hyperplasia

PubMed Central

Jiang, Xuechao; Zha, Bingbing; Liu, Xiaoming; Liu, Ronghua; Liu, Jun; Huang, Enyu; Qian, Tingting; Liu, Jiajing; Wang, Zhiming; Zhang, Dan; Wang, Luman; Chu, Yiwei

2016-01-01

Signal transducer and activator of transcription 6 (STAT6) is involved in epithelial cell growth. However, little is known regarding the STAT6 phosphorylation status in Graves' disease (GD) and its role in thyroid epithelial cells (TECs). In this study, we found that STAT6 phosphorylation (p-STAT6) was significantly increased in TECs from both GD patients and experimental autoimmune Graves' disease mice and that STAT6 deficiency ameliorated GD symptoms. Autocrine IL-4 signalling in TECs activated the phosphorylation of STAT6 via IL-4 R engagement, and the downstream targets of STAT6 were Bcl-xL and cyclin D1. Thus, the IL-4-STAT6-Bcl-xL/cyclin D1 pathway is crucial for TEC hyperplasia, which aggravates GD. More importantly, in vitro and in vivo experiments demonstrated that STAT6 phosphorylation inhibited by AS1517499 decreased TEC hyperplasia, thereby reducing serum T3 and T4 and ameliorating GD. Thus, our study reveals that in addition to the traditional pathogenesis of GD, in which autoantibody TRAb stimulates thyroid-stimulating hormone receptors and consequently produces T3, T4, TRAb could also trigger TECs producing IL-4, and IL-4 then acts in an autocrine manner to activate p-STAT6 signalling and stimulate unrestricted cell growth, thus aggravating GD. These findings suggest that STAT6 inhibitors could be potent therapeutics for treating GD. PMID:27906181

Human Umbilical Cord Perivascular Cells Exhibited Enhanced Migration Capacity towards Hepatocellular Carcinoma in Comparison with Bone Marrow Mesenchymal Stromal Cells: A Role for Autocrine Motility Factor Receptor

PubMed Central

Aquino, Jorge B.; Malvicini, Mariana; Bolontrade, Marcela; Podhajcer, Osvaldo; Garcia, Mariana G.; Mazzolini, Guillermo

2014-01-01

Hepatocellular carcinoma (HCC) is the third cause of cancer-related death worldwide. Unfortunately, the incidence and mortality associated with HCC are increasing. Therefore, new therapeutic strategies are urgently needed and the use of mesenchymal stromal cells (MSCs) as carrier of therapeutic genes is emerging as a promising option. Different sources of MSCs are being studied for cell therapy and bone marrow-derived cells are the most extensively explored; however, birth associated-tissues represent a very promising source. The aim of this work was to compare the in vitro and in vivo migration capacity between bone marrow MSCs (BM-MSCs) and human umbilical cord perivascular cells (HUCPVCs) towards HCC. We observed that HUCPVCs presented higher in vitro and in vivo migration towards factors released by HCC. The expression of autocrine motility factor (AMF) receptor, genes related with the availability of the receptor on the cell surface (caveolin-1 and -2) and metalloproteinase 3, induced by the receptor activation and important for cell migration, was increased in HUCPVCs. The chemotactic response towards recombinant AMF was increased in HUCPVCs compared to BM-MSCs, and its inhibition in the conditioned medium from HCC induced higher decrease in HUCPVC migration than in BM-MSC. Our results indicate that HUCPVCs could be a useful cellular source to deliver therapeutic genes to HCC. PMID:25147818

Human umbilical cord perivascular cells exhibited enhanced migration capacity towards hepatocellular carcinoma in comparison with bone marrow mesenchymal stromal cells: a role for autocrine motility factor receptor.

PubMed

Bayo, Juan; Fiore, Esteban; Aquino, Jorge B; Malvicini, Mariana; Rizzo, Manglio; Peixoto, Estanislao; Alaniz, Laura; Piccioni, Flavia; Bolontrade, Marcela; Podhajcer, Osvaldo; Garcia, Mariana G; Mazzolini, Guillermo

2014-01-01

Hepatocellular carcinoma (HCC) is the third cause of cancer-related death worldwide. Unfortunately, the incidence and mortality associated with HCC are increasing. Therefore, new therapeutic strategies are urgently needed and the use of mesenchymal stromal cells (MSCs) as carrier of therapeutic genes is emerging as a promising option. Different sources of MSCs are being studied for cell therapy and bone marrow-derived cells are the most extensively explored; however, birth associated-tissues represent a very promising source. The aim of this work was to compare the in vitro and in vivo migration capacity between bone marrow MSCs (BM-MSCs) and human umbilical cord perivascular cells (HUCPVCs) towards HCC. We observed that HUCPVCs presented higher in vitro and in vivo migration towards factors released by HCC. The expression of autocrine motility factor (AMF) receptor, genes related with the availability of the receptor on the cell surface (caveolin-1 and -2) and metalloproteinase 3, induced by the receptor activation and important for cell migration, was increased in HUCPVCs. The chemotactic response towards recombinant AMF was increased in HUCPVCs compared to BM-MSCs, and its inhibition in the conditioned medium from HCC induced higher decrease in HUCPVC migration than in BM-MSC. Our results indicate that HUCPVCs could be a useful cellular source to deliver therapeutic genes to HCC.

Tumor cell-targeted delivery of CRISPR/Cas9 by aptamer-functionalized lipopolymer for therapeutic genome editing of VEGFA in osteosarcoma.

PubMed

Liang, Chao; Li, Fangfei; Wang, Luyao; Zhang, Zong-Kang; Wang, Chao; He, Bing; Li, Jie; Chen, Zhihao; Shaikh, Atik Badshah; Liu, Jin; Wu, Xiaohao; Peng, Songlin; Dang, Lei; Guo, Baosheng; He, Xiaojuan; Au, D W T; Lu, Cheng; Zhu, Hailong; Zhang, Bao-Ting; Lu, Aiping; Zhang, Ge

2017-12-01

Osteosarcoma (OS) is a highly aggressive pediatric cancer, characterized by frequent lung metastasis and pathologic bone destruction. Vascular endothelial growth factor A (VEGFA), highly expressed in OS, not only contributes to angiogenesis within the tumor microenvironment via paracrine stimulation of vascular endothelial cells, but also acts as an autocrine survival factor for tumor cell themselves, thus making it a promising therapeutic target for OS. CRISPR/Cas9 is a versatile genome editing technology and holds tremendous promise for cancer treatment. However, a major bottleneck to achieve the therapeutic potential of the CRISPR/Cas9 is the lack of in vivo tumor-targeted delivery systems. Here, we screened an OS cell-specific aptamer (LC09) and developed a LC09-functionalized PEG-PEI-Cholesterol (PPC) lipopolymer encapsulating CRISPR/Cas9 plasmids encoding VEGFA gRNA and Cas9. Our results demonstrated that LC09 facilitated selective distribution of CRISPR/Cas9 in both orthotopic OS and lung metastasis, leading to effective VEGFA genome editing in tumor, decreased VEGFA expression and secretion, inhibited orthotopic OS malignancy and lung metastasis, as well as reduced angiogenesis and bone lesion with no detectable toxicity. The delivery system simultaneously restrained autocrine and paracrine VEGFA signaling in tumor cells and could facilitate translating CRISPR-Cas9 into clinical cancer treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Kyung-Jin; Department of Biomedical Science, College of Medicine, Seoul National University, Seoul 110-799; Yun, Jang-Hyuk

Highlights: • PEDF was expressed and induced during the involuting phase of IH. • PEDF inhibited the cell growth of the involuting HemECs in an autocrine manner. • PEDF suppression restored the impaired cell growth of the involuting HemECs. - Abstract: Hemangioma is a benign tumor derived from abnormal blood vessel growth. Unlike other vascular tumor counterparts, a hemangioma is known to proliferate during its early stage but it is followed by a stage of involution where regression of the tumor occurs. The critical onset leading to the involution of hemangioma is currently not well understood. This study focused onmore » the molecular identities of the involution of hemangioma. We demonstrated that a soluble factor released from the involuting phase of hemangioma-derived endothelial cells (HemECs) and identified pigment epithelium-derived factor (PEDF) as an anti-angiogenic factor that was associated with the growth inhibition of the involuting HemECs. The growth inhibition of the involuting HemECs was reversed by suppression of PEDF in the involuting HemECs. Furthermore, we found that PEDF was more up-regulated in the involuting phase of hemangioma tissues than in the proliferating or the involuted. Taken together, we propose that PEDF accelerates the involution of hemangioma by growth inhibition of HemECs in an autocrine manner. The regulatory mechanism of PEDF expression could be a potential therapeutic target to treat hemangiomas.« less

Immune Escape Mechanisms in Colorectal Cancer Pathogenesis and Liver Metastasis

PubMed Central

Remo, Andrea; Febbraro, Antonio; Sabatino, Lina; Manfrin, Erminia; Ceccarelli, Michele; Colantuoni, Vittorio

2014-01-01

Over the past decade, growing evidence indicates that the tumor microenvironment (TME) contributes with genomic/epigenomic aberrations of malignant cells to enhance cancer cells survival, invasion, and dissemination. Many factors, produced or de novo synthesized by immune, stromal, or malignant cells, acting in a paracrine and autocrine fashion, remodel TME and the adaptive immune response culminating in metastasis. Taking into account the recent accomplishments in the field of immune oncology and using metastatic colorectal cancer (mCRC) as a model, we propose that the evasion of the immune surveillance and metastatic spread can be achieved through a number of mechanisms that include (a) intrinsic plasticity and adaptability of immune and malignant cells to paracrine and autocrine stimuli or genotoxic stresses; (b) alteration of positional schemes of myeloid-lineage cells, produced by factors controlling the balance between tumour-suppressing and tumour-promoting activities; (c) acquisition by cancer cells of aberrant immune-phenotypic traits (NT5E/CD73, CD68, and CD163) that enhance the interactions among TME components through the production of immune-suppressive mediators. These properties may represent the driving force of metastatic progression and thus clinically exploitable for cancer prevention and therapy. In this review we summarize results and suggest new hypotheses that favour the growing impact of tumor-infiltrating immune cells on tumour progression, metastasis, and therapy resistance. PMID:24741617

Immune-Pineal Axis: Nuclear Factor κB (NF-κB) Mediates the Shift in the Melatonin Source from Pinealocytes to Immune Competent Cells

PubMed Central

Markus, Regina P; Cecon, Erika; Pires-Lapa, Marco Antonio

2013-01-01

Pineal gland melatonin is the darkness hormone, while extra-pineal melatonin produced by the gonads, gut, retina, and immune competent cells acts as a paracrine or autocrine mediator. The well-known immunomodulatory effect of melatonin is observed either as an endocrine, a paracrine or an autocrine response. In mammals, nuclear translocation of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) blocks noradrenaline-induced melatonin synthesis in pinealocytes, which induces melatonin synthesis in macrophages. In addition, melatonin reduces NF-κB activation in pinealocytes and immune competent cells. Therefore, pathogen- or danger-associated molecular patterns transiently switch the synthesis of melatonin from pinealocytes to immune competent cells, and as the response progresses melatonin inhibition of NF-κB activity leads these cells to a more quiescent state. The opposite effect of NF-κB in pinealocytes and immune competent cells is due to different NF-κB dimers recruited in each phase of the defense response. This coordinated shift of the source of melatonin driven by NF-κB is called the immune-pineal axis. Finally, we discuss how this concept might be relevant to a better understanding of pathological conditions with impaired melatonin rhythms and hope it opens new horizons for the research of side effects of melatonin-based therapies. PMID:23708099

CXC chemokine ligand 4 (CXCL4) down-regulates CC chemokine receptor expression on human monocytes.

PubMed

Schwartzkopff, Franziska; Petersen, Frank; Grimm, Tobias Alexander; Brandt, Ernst

2012-02-01

During acute inflammation, monocytes are essential in abolishing invading micro-organisms and encouraging wound healing. Recruitment by CC chemokines is an important step in targeting monocytes to the inflamed tissue. However, cell surface expression of the corresponding chemokine receptors is subject to regulation by various endogenous stimuli which so far have not been comprehensively identified. We report that the platelet-derived CXC chemokine ligand 4 (CXCL4), a known activator of human monocytes, induces down-regulation of CC chemokine receptors (CCR) 1, -2, and -5, resulting in drastic impairment of monocyte chemotactic migration towards cognate CC chemokine ligands (CCL) for these receptors. Interestingly, CXCL4-mediated down-regulation of CCR1, CCR2 and CCR5 was strongly dependent on the chemokine's ability to stimulate autocrine/paracrine release of TNF-α. In turn, TNF-α induced the secretion CCL3 and CCL4, two chemokines selective for CCR1 and CCR5, while the secretion of CCR2-ligand CCL2 was TNF-α-independent. Culture supernatants of CXCL4-stimulated monocytes as well as chemokine-enriched preparations thereof reproduced CXCL4-induced CCR down-regulation. In conclusion, CXCL4 may act as a selective regulator of monocyte migration by stimulating the release of autocrine, receptor-desensitizing chemokine ligands. Our results stress a co-ordinating role for CXCL4 in the cross-talk between platelets and monocytes during early inflammation.

Islet amyloid polypeptide exerts a novel autocrine action in β-cell signaling and proliferation.

PubMed

Visa, Montse; Alcarraz-Vizán, Gema; Montane, Joel; Cadavez, Lisa; Castaño, Carlos; Villanueva-Peñacarrillo, María Luisa; Servitja, Joan-Marc; Novials, Anna

2015-07-01

The toxic effects of human islet amyloid polypeptide (IAPP) on pancreatic islets have been widely studied. However, much less attention has been paid to the physiologic actions of IAPP on pancreatic β cells, which secrete this peptide together with insulin upon glucose stimulation. Here, we aimed to explore the signaling pathways and mitogenic actions of IAPP on β cells. We show that IAPP activated Erk1/2 and v-akt murine thymoma viral oncogene homolog 1 (Akt) at the picomolar range (10-100 pM) in mouse pancreatic islets and MIN6 β cells cultured at low glucose concentrations. In contrast, IAPP decreased the induction of these pathways by high glucose levels. Consistently, IAPP induced a 1.7-fold increase of β-cell proliferation at low-glucose conditions, whereas it reduced β-cell proliferation at high glucose levels. Strikingly, the specific antagonist of the IAPP receptor AC187 (100 nM) decreased the activation of Erk1/2 and Akt and reduced β-cell proliferation by 24% in glucose-stimulated β cells, uncovering a key role of endogenously released IAPP in β-cell responses to glucose. We conclude that exogenously added IAPP exerts a dual effect on β-cell mitogenic signaling and proliferation, depending on the glucose concentration. Importantly, secreted IAPP contributes to the signaling and mitogenic response of β cells to glucose through an autocrine mechanism. © FASEB.

Hedgehog signalling stimulates precursor cell accumulation and impairs epithelial maturation in the murine oesophagus.

PubMed

van Dop, Willemijn A; Rosekrans, Sanne L; Uhmann, Anja; Jaks, Viljar; Offerhaus, G Johan A; van den Bergh Weerman, Marius A; Kasper, Maria; Heijmans, Jarom; Hardwick, James C H; Verspaget, Hein W; Hommes, Daan W; Toftgård, Rune; Hahn, Heidi; van den Brink, Gijs R

2013-03-01

In the intestine Hedgehog (Hh) signalling is directed from epithelium to mesenchyme and negatively regulates epithelial precursor cell fate. The role of Hh signalling in the oesophagus has not been studied in vivo. Here the authors examined the role of Hh signalling in epithelial homeostasis of oesophagus. The authors used transgenic mice in which the Hh receptor Patched1 (Ptch1) could be conditionally inactivated in a body-wide manner and mice in which Gli1 could be induced specifically in the epithelium of the skin and oesophagus. Effects on epithelial homeostasis of the oesophagus were examined using immunohistochemistry, in situ hybridisation, transmission electron microscopy and real-time PCR. Hh signalling was examined in patients with oesophageal squamous cell carcinoma (SCC) by quantitative real-time PCR. Sonic Hh is signalled in an autocrine manner in the basal layer of the oesophagus. Activation of Hh signalling resulted in an expansion of the epithelial precursor cell compartment and failure of epithelial maturation and migration. Levels of Hh targets GLI1, HHIP and PTCH1 were increased in SCC compared with normal tissue from the same patients. Here the authors find that Hh signalling positively regulates the precursor cell compartment in the oesophageal epithelium in an autocrine manner. Since Hh signalling targets precursor cells in the oesophageal epithelium and signalling is increased in SCCs, Hh signalling may be involved in oesophageal SCC formation.

In vitro proliferation of axotomized rat facial nucleus-derived activated microglia in an autocrine fashion.

PubMed

Nakajima, Kazuyuki; Graeber, Manuel B; Sonoda, Maya; Tohyama, Yoko; Kohsaka, Shinichi; Kurihara, Tadashi

2006-08-01

Transection of rat adult facial nerve leads to an increase in the number of activated microglia in the facial nucleus (FN), with a peak in proliferation 3 days after transection. To investigate the characteristics of these activated microglia, we isolated the cells with high purity from axotomized FN (axFN) 3 days after transection according to the previously reported procedure for explant culture. The isolated microglia exhibited immunocytochemical properties similar to those in vivo, and their numbers increased approximately five- to sevenfold over a period of 10 days without the addition of any mitogens, suggesting that self-reproduction was occurring. Actually, the microglia actively incorporated bromodeoxyuridine (BrdU) and strongly expressed an S-phase-specific protein marker, proliferating cell nuclear antigen (PCNA). To examine the mechanism underlying this proliferation, the expression of the mitogens and specific receptors of the microglia were analyzed in conditioned medium (CM) and cells. Macrophage-colony stimulating factor (M-CSF) and granulocyte macrophage-CSF (GM-CSF) were detected in the CM as well as in the cells. Their specific receptor proteins, c-Fms and GMCSFRalpha, were also detected in the cell homogenate. These proliferating microglia were not found to produce deleterious factors for neurons. In summary, the microglia isolated from the axFN were found to be proliferative in an autocrine fashion and to have some cellular properties in common with those observed in vivo.

Development of a Small Molecule P2X7R Antagonist as a Treatment for Acute SCI

DTIC Science & Technology

2013-10-01

microglia in response to SCI, and of the role of P2X7 receptor activation in that process . Indeed, in parallel work using uninjured human brain tissue...distinct glial fates are instructed, and how that process may be manipulated for therapeutic purposes. Thus, on the basis of the injury-associated...autocrine loop for the self -maintenance of glial progenitors, the perturbation of which might dictate progenitor recruitment as either reactive glia or

The Role and Regulation of TNF-Alpha in Normal Rat Mammary Gland During Development and in Breast Cancer.

DTIC Science & Technology

1996-07-01

autocrine synthesis of TNFcx by the MEC as well. Normally, there is strict control of the expression of this cytokine; however, it is possible that any...1,2-benz-anthracene (DMBA) (Sigma, St. Louis, MO) (in corn oil) p.o. using standard protocols (30) or via i.p. injection of 1-methyl-l- nitrosourea ...Beutler, B. Dexamethasone and pentoxifylline inhibit endotoxin- induced cachectin/tumor necrosis factor synthesis at separate points in the signalling

Novel Growth Factor as Prognostic Marker for Estrogen-Independence in Breast Cancer

DTIC Science & Technology

2002-08-01

factor (PCDGF, also known as progranulin ) is a novel autocrine growth factor shown to be overexpressed and to be mitogenic in human breast cancer cell...kDa glycoprotein originally purified from the highly tumorigenic mouse teratoma-derived cell line PC (1, 2). PCDGF (also known as progranulin ) is the...requirement for the insulin-like growth factor 1 receptor for growth in vitro. J Biol Chem, 273: 20078-20083, 1998. 6. He, Z. and Bateman, A. Progranulin gene

High-mobility group box-1 as an autocrine trophic factor in white matter stroke.

PubMed

Choi, Jun Young; Cui, Yuexian; Chowdhury, Samma Tasneem; Kim, Byung Gon

2017-06-20

Maintenance of white matter integrity in health and disease is critical for a variety of neural functions. Ischemic stroke in the white matter frequently results in degeneration of oligodendrocytes (OLs) and myelin. Previously, we found that toll-like receptor 2 (TLR2) expressed in OLs provides cell-autonomous protective effects on ischemic OL death and demyelination in white matter stroke. Here, we identified high-mobility group box-1 (HMGB1) as an endogenous TLR2 ligand that promotes survival of OLs under ischemic stress. HMGB1 rapidly accumulated in the culture medium of OLs exposed to oxygen-glucose deprivation (OGD). This conditioned medium exhibited a protective activity against ischemic OL death that was completely abolished by immunodepletion of HMGB1. Knockdown of HMGB1 or application of glycyrrhizin, a specific HMGB1 inhibitor, aggravated OGD-induced OL death, and recombinant HMGB1 application reduced the extent of OL death in a TLR2-dependent manner. We confirmed that cytosolic translocation of HMGB1 and activation of TLR2-mediated signaling pathways occurred in a focal white matter stroke model induced by endothelin-1 injection. Animals with glycyrrhizin coinjection showed an expansion of the demyelinating lesion in a TLR2-dependent manner, accompanied by aggravation of sensorimotor behavioral deficits. These results indicate that HMGB1/TLR2 activates an autocrine trophic signaling pathways in OLs and myelin to maintain structural and functional integrity of the white matter under ischemic conditions.

Bioreactor perfusion system for the long-term maintenance of tissue-engineered skeletal muscle organoids

NASA Technical Reports Server (NTRS)

Chromiak, J. A.; Shansky, J.; Perrone, C.; Vandenburgh, H. H.

1998-01-01

Three-dimensional skeletal muscle organ-like structures (organoids) formed in tissue culture by fusion of proliferating myoblasts into parallel networks of long, unbranched myofibers provide an in vivo-like model for examining the effects of growth factors, tension, and space flight on muscle cell growth and metabolism. To determine the feasibility of maintaining either avian or mammalian muscle organoids in a commercial perfusion bioreactor system, we measured metabolism, protein turnover. and autocrine/paracrine growth factor release rates. Medium glucose was metabolized at a constant rate in both low-serum- and serum-free media for up to 30 d. Total organoid noncollagenous protein and DNA content decreased approximately 22-28% (P < 0.05) over a 13-d period. Total protein synthesis rates could be determined accurately in the bioreactors for up to 30 h and total protein degradation rates could be measured for up to 3 wk. Special fixation and storage conditions necessary for space flight studies were validated as part of the studies. For example, the anabolic autocrine/paracrine skeletal muscle growth factors prostaglandin F2alpha (PGF2alpha) and insulin-like growth factor-1 (IGF-1) could be measured accurately in collected media fractions, even after storage at 37 degrees C for up to 10 d. In contrast, creatine kinase activity (a marker of cell damage) in collected media fractions was unreliable. These results provide initial benchmarks for long-term ex vivo studies of tissue-engineered skeletal muscle.

Vitamin D in health and disease.

PubMed

Heaney, Robert P

2008-09-01

Vitamin D functions in the body through both an endocrine mechanism (regulation of calcium absorption) and an autocrine mechanism (facilitation of gene expression). The former acts through circulating calcitriol, whereas the latter, which accounts for more than 80% of the metabolic utilization of the vitamin each day, produces, uses, and degrades calcitriol exclusively intracellularly. In patients with end-stage kidney disease, the endocrine mechanism is effectively disabled; however, the autocrine mechanism is able to function normally so long as the patient has adequate serum levels of 25(OH)D, on which its function is absolutely dependent. For this reason, calcitriol and its analogs do not constitute adequate replacement in managing vitamin D needs of such patients. Optimal serum 25(OH)D levels are greater than 32 ng/mL (80 nmol/L). The consequences of low 25(OH)D status include increased risk of various chronic diseases, ranging from hypertension to diabetes to cancer. The safest and most economical way to ensure adequate vitamin D status is to use oral dosing of native vitamin D. (Both daily and intermittent regimens work well.) Serum 25(OH)D can be expected to rise by about 1 ng/mL (2.5 nmol/L) for every 100 IU of additional vitamin D each day. Recent data indicate that cholecalciferol (vitamin D(3)) is substantially more potent than ergocalciferol (vitamin D(2)) and that the safe upper intake level for vitamin D(3) is 10,000 IU/d.

Involvement of human decidual cell-expressed tissue factor in uterine hemostasis and abruption.

PubMed

Lockwood, C J; Paidas, M; Murk, W K; Kayisli, U A; Gopinath, A; Huang, S J; Krikun, G; Schatz, F

2009-11-01

Vascular injury increases access and binding of plasma-derived factor VII to perivascular cell membrane-bound tissue factor (TF). The resulting TF/VIIa complex promotes hemostasis by cleaving pro-thrombin to thrombin leading to the fibrin clot. In human pregnancy, decidual cell-expressed TF prevents decidual hemorrhage (abruption). During placentation, trophoblasts remodel decidual spiral arteries into high conductance vessels. Shallow trophoblast invasion impedes decidual vascular conversion, producing an inadequate uteroplacental blood flow that elicits abruption-related placental ischemia. Thrombin induces several biological effects via cell surface protease activated receptors. In first trimester human DCs thrombin increases synthesis of sFlt-1, which elicits placental ischemia by impeding angiogenesis-related decidual vascular remodeling. During pregnacy, the fibrillar collagen-rich amnion and choriodecidua extracellular matrix (ECM) provides greater than additive tensile strength and structural integrity. Thrombin acts as an autocrine/paracrine mediator that degrades these ECMs by augmenting decidual cell expression of: 1) matrix metalloproteinases and 2) interleukin-8, a key mediator of abruption-associated decidual infiltration of neutrophils, which express several ECM degrading proteases. Among the cell types at the maternal fetal interface at term, TF expression is highest in decidual cells indicating that this TF meets the hemostatic demands of labor and delivery. TF expression in cultured term decidual cells is enhanced by progestin and thrombin suggesting that the maintenance of elevated circulating progesterone provides hemostatic protection and that abruption-generated thrombin acts in an autocrine/paracrine fashion on decidual cells to promote hemostasis via enhanced TF expression.

Stimulation of mesenchymal stromal cells (MSCs) via TLR3 reveals a novel mechanism of autocrine priming

PubMed Central

Dumitru, Claudia A.; Hemeda, Hatim; Jakob, Mark; Lang, Stephan; Brandau, Sven

2014-01-01

Mesenchymal stem/stromal cells (MSCs) are emerging as important regulators of innate and adaptive immunity. In this context, both proinflammatory and anti-inflammatory effects have been described for MSCs. The mechanisms mediating this functional plasticity are poorly characterized at present. Here, we investigated the inflammatory responses of MSCs isolated from human nasal mucosa (nmMSCs) upon challenge with different Toll-like receptor (TLR) ligands. We found that TLR3 ligands induced the strongest release of both proinflammatory cytokines [interleukin (IL)-6 and IL-8] and type I interferon by nmMSCs compared with other TLR ligands. Notably, TLR3 ligands triggered a biphasic cytokine response, with an early peak of type I interferon at 4 h poststimulation and a late release of proinflammatory cytokines at 24 h poststimulation. While the early interferon response was subject to direct stimulation, the proinflammatory response was regulated by factors released during the early cytokine response, which subsequently enhanced sensitivity to TLR3 ligation and amplified the production of IL-6 and IL-8 but not that of interferon. Taken together, our findings indicate that TLR3 ligands polarize the inflammatory phenotype of MSCs in a time-dependent manner. Thus, our study proposes a novel model that helps to explain the strikingly dichotomous functionality of MSCs in inflammation and immunoregulation.—Dumitru, C. A., Hemeda, H., Jakob, M., Lang, S., Brandau, S. Stimulation of mesenchymal stromal cells (MSCs) via TLR3 reveals a novel mechanism of autocrine priming. PMID:24830384

The Insulin Receptor: A New Target for Cancer Therapy

PubMed Central

Malaguarnera, Roberta; Belfiore, Antonino

2011-01-01

A large body of evidences have shown that both the IGF-I receptor (IGF-IR) and the insulin receptor (IR) play a role in cancer development and progression. In particular, IR overactivation by IGF-II is common in cancer cells, especially in dedifferentiated/stem-like cells. In spite of these findings, until very recently, only IGF-IR but not IR has been considered a target in cancer therapy. Although several preclinical studies have showed a good anti-cancer activity of selective anti-IGF-IR drugs, the results of the clinical first trials have been disappointing. In fact, only a small subset of malignant tumors has shown an objective response to these therapies. Development of resistance to anti-IGF-IR drugs may include upregulation of IR isoform A (IR-A) in cancer cells and its overactivation by increased secretion of autocrine IGF-II. These findings have led to the concept that co-targeting IR together with IGF-IR may increase therapy efficacy and prevent adaptive resistance to selective anti-IGF-IR drugs. IR blockade should be especially considered in tumors with high IR-A:IGF-IR ratio and high levels of autocrine IGF-II. Conversely, insulin sensitizers, which ameliorate insulin resistance associated with metabolic disorders and cancer treatments, may have important implications for cancer prevention and management. Only few drugs co-targeting the IR and IGF-IR are currently available. Ideally, future IR targeting strategies should be able to selectively inhibit the tumor promoting effects of IR without impairing its metabolic effects. PMID:22654833

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varley, Claire; Hill, Gemma; Pellegrin, Stephanie

Regeneration of the urothelium is rapid and effective in order to maintain a barrier to urine following tissue injury. Whereas normal human urothelial (NHU) cells are mitotically quiescent and G0 arrested in situ, they rapidly enter the cell cycle upon seeding in primary culture and show reversible growth arrest at confluency. We have used this as a model to investigate the role of EGF receptor signaling in urothelial regeneration and wound-healing. Transcripts for HER-1, HER-2, and HER-3 were expressed by quiescent human urothelium in situ. Expression of HER-1 was upregulated in proliferating cultures, whereas HER-2 and HER-3 were more associatedmore » with a growth-arrested phenotype. NHU cells could be propagated in the absence of exogenous EGF, but autocrine signaling through HER-1 via the MAPK and PI3-kinase pathways was essential for proliferation and migration during urothelial wound repair. HB-EGF was expressed by urothelium in situ and HB-EGF, epiregulin, TGF-{alpha}, and amphiregulin were expressed by proliferating NHU cells. Urothelial wound repair in vitro was attenuated by neutralizing antibodies against HER-1 ligands, particularly amphiregulin. By contrast, the same ligands applied exogenously promoted migration, but inhibited proliferation, implying that HER-1 ligands provoke differential effects in NHU cells depending upon whether they are presented as soluble or juxtacrine ligands. We conclude that proliferation and migration during wound healing in NHU cells are mediated through an EGFR autocrine signalling loop and our results implicate amphiregulin as a key mediator.« less

A secreted protein is an endogenous chemorepellant in Dictyostelium discoideum

PubMed Central

Phillips, Jonathan E.; Gomer, Richard H.

2012-01-01

Chemorepellants may play multiple roles in physiological and pathological processes. However, few endogenous chemorepellants have been identified, and how they function is unclear. We found that the autocrine signal AprA, which is produced by growing Dictyostelium discoideum cells and inhibits their proliferation, also functions as a chemorepellant. Wild-type cells at the edge of a colony show directed movement outward from the colony, whereas cells lacking AprA do not. Cells show directed movement away from a source of recombinant AprA and dialyzed conditioned media from wild-type cells, but not dialyzed conditioned media from aprA− cells. The secreted protein CfaD, the G protein Gα8, and the kinase QkgA are necessary for the chemorepellant activity of AprA as well as its proliferation-inhibiting activity, whereas the putative transcription factor BzpN is dispensable for the chemorepellant activity of AprA but necessary for inhibition of proliferation. Phospholipase C and PI3 kinases 1 and 2, which are necessary for the activity of at least one other chemorepellant in Dictyostelium, are not necessary for recombinant AprA chemorepellant activity. Starved cells are not repelled by recombinant AprA, suggesting that aggregation-phase cells are not sensitive to the chemorepellant effect. Cell tracking indicates that AprA affects the directional bias of cell movement, but not cell velocity or the persistence of cell movement. Together, our data indicate that the endogenous signal AprA acts as an autocrine chemorepellant for Dictyostelium cells. PMID:22711818

The insulin response integrates increased TGF-β signaling through Akt-induced enhancement of cell surface delivery of TGF-β receptors

PubMed Central

Budi, Erine H.; Muthusamy, Baby Periyanayaki; Derynck, Rik

2015-01-01

Increased activity of transforming growth factor β (TGF-β), which binds to and stimulates cell surface receptors, contributes to cancer progression and fibrosis by driving epithelial cells toward a migratory mesenchymal phenotype and increasing the abundance of extracellular matrix proteins. The abundance of TGF-β receptors at the cell surface determines cellular responsiveness to TGF-β, which is often produced by the same cells that have the receptors, and thus serves as an autocrine signal. We found that Akt-mediated phosphorylation of AS160, a RabGAP [guanosine triphosphatase (GTPase)-activating protein] promoted the translocation of TGF-β receptors from intracellular stores to the plasma membrane of mouse embryonic fibroblasts (MEFs) and NMuMG epithelial cells. Consequently, insulin, which is commonly used to treat hyperglycemia and activates Akt signaling, increased the amount of TGF-β receptors at the cell surface, thereby enhancing TGF-β responsiveness. This insulin-induced increase in autocrine TGF-β signaling contributed to insulin-induced gene expression responses, attenuated the epithelial phenotype, and promoted the migration of NMuMG cells. Furthermore, the enhanced delivery of TGF-β receptors at the cell surface enabled insulin to increase TGF-β-induced gene responses. The enhancement of TGF-β responsiveness in response to Akt activation may help to explain the biological effects of insulin, the progression of cancers in which Akt is activated, and the increased incidence of fibroses in diabetes. PMID:26420907

Oxytocin and bone

PubMed Central

Sun, Li; Zaidi, Mone; Zallone, Alberta

2014-01-01

One of the most meaningful results recently achieved in bone research has been to reveal that the pituitary hormones have profound effect on bone, so that the pituitary-bone axis has become one of the major topics in skeletal physiology. Here, we discuss the relevant evidence about the posterior pituitary hormone oxytocin (OT), previously thought to exclusively regulate parturition and breastfeeding, which has recently been established to directly regulate bone mass. Both osteoblasts and osteoclasts express OT receptors (OTR), whose stimulation enhances bone mass. Consistent with this, mice deficient in OT or OTR display profoundly impaired bone formation. In contrast, bone resorption remains unaffected in OT deficiency because, even while OT stimulates the genesis of osteoclasts, it inhibits their resorptive function. Furthermore, in addition to its origin from the pituitary, OT is also produced by bone marrow osteoblasts acting as paracrine-autocrine regulator of bone formation modulated by estrogens. In turn, the power of estrogen to increase bone mass is OTR-dependent. Therefore, OTR−/− mice injected with 17β-estradiol do not show any effects on bone formation parameters, while the same treatment increases bone mass in wild-type mice. These findings together provide evidence for an anabolic action of OT in regulating bone mass and suggest that bone marrow OT may enhance the bone-forming action of estrogen through an autocrine circuit. This established new physiological role for OT in the maintenance of skeletal integrity further suggests the potential use of this hormone for the treatment of osteoporosis. PMID:25209411

A phosphatase-independent gain-of-function mutation in PTEN triggers aberrant cell growth in astrocytes through an autocrine IGF-1 loop.

PubMed

Fernández, S; Genis, L; Torres-Alemán, I

2014-08-07

Loss-of-function mutations in the phosphatase PTEN (phosphatase and tensin homolog deleted on chromosome10) contribute to aberrant cell growth in part through upregulation of the mitogenic IGF-1/PI3K/Akt pathway. In turn, this pathway exerts a homeostatic feedback over PTEN. Using mutagenesis analysis to explore a possible impact of this mutual control on astrocyte growth, we found that truncation of the C-terminal region of PTEN (Δ51) associates with a marked increase in NFκB activity, a transcription factor overactivated in astrocyte tumors. Whereas mutations of PTEN are considered to lead to a loss-of-function, PTENΔ51, a truncation that comprises a region frequently mutated in human gliomas, displayed a neomorphic (gain-of-function) activity that was independent of its phosphatase activity. This gain-of-function of PTENΔ51 includes stimulation of IGF-1 synthesis through protein kinase A activation of the IGF-1 promoter. Increased IGF-1 originates an autocrine loop that activates Akt and NFκB. Constitutive activation of NFκB in PTENΔ51-expressing astrocytes leads to aberrant cell growth; astrocytes expressing this mutant PTEN generate colonies in vitro and tumors in vivo. Mutations converting a tumor suppressor such as PTEN into a tumor promoter through a gain-of-function involving IGF-1 production may further our understanding of the role played by this growth factor in glioma growth and help us define druggable targets for personalized therapy.

Microfluidic device capable of medium recirculation for non-adherent cell culture

PubMed Central

Dixon, Angela R.; Rajan, Shrinidhi; Kuo, Chuan-Hsien; Bersano, Tom; Wold, Rachel; Futai, Nobuyuki; Takayama, Shuichi; Mehta, Geeta

2014-01-01

We present a microfluidic device designed for maintenance and culture of non-adherent mammalian cells, which enables both recirculation and refreshing of medium, as well as easy harvesting of cells from the device. We demonstrate fabrication of a novel microfluidic device utilizing Braille perfusion for peristaltic fluid flow to enable switching between recirculation and refresh flow modes. Utilizing fluid flow simulations and the human promyelocytic leukemia cell line, HL-60, non-adherent cells, we demonstrate the utility of this RECIR-REFRESH device. With computer simulations, we profiled fluid flow and concentration gradients of autocrine factors and found that the geometry of the cell culture well plays a key role in cell entrapping and retaining autocrine and soluble factors. We subjected HL-60 cells, in the device, to a treatment regimen of 1.25% dimethylsulfoxide, every other day, to provoke differentiation and measured subsequent expression of CD11b on day 2 and day 4 and tumor necrosis factor-alpha (TNF-α) on day 4. Our findings display perfusion sensitive CD11b expression, but not TNF-α build-up, by day 4 of culture, with a 1:1 ratio of recirculation to refresh flow yielding the greatest increase in CD11b levels. RECIR-REFRESH facilitates programmable levels of cell differentiation in a HL-60 non-adherent cell population and can be expanded to other types of non-adherent cells such as hematopoietic stem cells. PMID:24753733

High expression of neutral endopeptidase in idiopathic diffuse hyperplasia of pulmonary neuroendocrine cells.

PubMed

Cohen, A J; King, T E; Gilman, L B; Magill-Solc, C; Miller, Y E

1998-11-01

Idiopathic diffuse hyperplasia of pulmonary neuroendocrine cells (IDHPNC) is a clinicopathological entity characterized by a diffuse hyperplasia of neuroendocrine cells involving distal bronchi and bronchioles. The pathogenesis of this syndrome remains unknown. The hyperplastic neuroendocrine (NE) cells contain multiple neuropeptides, including the bombesinlike peptides (BLP), which are likely important in the pathogenesis of the disorder by stimulating proliferation of fibroblasts in a paracrine fashion and the NE cells themselves in an autocrine manner. Neutral endopeptidase (NEP) is a cell-surface enzyme that hydrolyzes BLP and other bioactive peptides. Low or undetectable NEP is present in many primary lung cancers and cell lines. Low NEP expression could increase neuropeptide-induced autocrine effects by increasing local levels of neuropeptides. We hypothesized that IDHPNC was associated with low or absent NEP expression. NEP expression was assayed in patients with IDHPNC (n = 3) and was compared with expression in patients with idiopathic pulmonary fibrosis (n = 5), hypersensitivity pneumonitis (n = 5), and normal lung (n = 4) using immunohistochemistry, ELISA, activity assay, and Western blot analysis. By these assays, NEP expression was highest in lungs affected by IDHPNC. NEP mRNA, as assessed in IDHPNC lung tissue by RT-PCR, was the expected size and free of mutation between bp 238-2437. Therefore, IDHPNC is unlikely to be the result of a defect in NEP expression. The apparent increase in NEP expression in lung tissue from patients with IDHPNC may reflect a compensatory increase that partly counteracts abundant neuropeptides, including BLP, present in this disorder.

Pro-neurotensin/neuromedin N expression and processing in human colon cancer cell lines.

PubMed

Rovère, C; Barbero, P; Maoret, J J; Laburthe, M; Kitabgi, P

1998-05-08

The regulatory peptide neurotensin NT has been proposed to exert an autocrine trophic effect on human colon cancers. In the present study, pro-neurotensin/neuromedin N (proNT/NN) expression and processing were investigated in 13 human colon cancer cell lines using a combination of radioimmunoassay and HPLC techniques. All 13 cell lines displayed low to moderate levels of proNT/NN ranging from 10 to 250 fmol/mg protein. However, only 6 (HCT8, LoVo, HT29, C119A, LS174T, and coloDM320) processed the precursor. Three of the latter (HCT8, LS174T, and coloDM320) were analysed in detail with regard to proNT/NN processing pattern and were found to produce NT and large precursor fragments ending with the NT or NN sequence. They had no detectable level of NN. Such a processing pattern resembles that generated by the prohormone convertase PC5. Northern and Western blot analysis of prohormone convertase expression in the 3 cell lines revealed that they were devoid of PC1 and PC2, whereas they all expressed PC5. These data indicate that proNT/NN is a good marker of human colon cancer cell lines while NT is found in only about half of the cell lines. They also suggest that, in addition to NT, several proNT/NN-derived products, possibly generated by PC5, might exert an autocrine positive effect on human colon cancer growth.

Acetylcholine released by endothelial cells facilitates flow‐mediated dilatation

PubMed Central

Wilson, Calum; Lee, Matthew D.

2016-01-01

Key points The endothelium plays a pivotal role in the vascular response to chemical and mechanical stimuli.The endothelium is exquisitely sensitive to ACh, although the physiological significance of ACh‐induced activation of the endothelium is unknown.In the present study, we investigated the mechanisms of flow‐mediated endothelial calcium signalling.Our data establish that flow‐mediated endothelial calcium responses arise from the autocrine action of non‐neuronal ACh released by the endothelium. Abstract Circulating blood generates frictional forces (shear stress) on the walls of blood vessels. These frictional forces critically regulate vascular function. The endothelium senses these frictional forces and, in response, releases various vasodilators that relax smooth muscle cells in a process termed flow‐mediated dilatation. Although some elements of the signalling mechanisms have been identified, precisely how flow is sensed and transduced to cause the release of relaxing factors is poorly understood. By imaging signalling in large areas of the endothelium of intact arteries, we show that the endothelium responds to flow by releasing ACh. Once liberated, ACh acts to trigger calcium release from the internal store in endothelial cells, nitric oxide production and artery relaxation. Flow‐activated release of ACh from the endothelium is non‐vesicular and occurs via organic cation transporters. ACh is generated following mitochondrial production of acetylCoA. Thus, we show ACh is an autocrine signalling molecule released from endothelial cells, and identify a new role for the classical neurotransmitter in endothelial mechanotransduction. PMID:27730645

Interleukin 6 inhibits proliferation and, in cooperation with an epidermal growth factor receptor autocrine loop, increases migration of T47D breast cancer cells.

PubMed

Badache, A; Hynes, N E

2001-01-01

Interleukin (IL)-6, a multifunctional regulator of immune response, hematopoiesis, and acute phase reactions, has also been shown to regulate cancer cell proliferation. We have investigated IL-6 signaling pathways and cellular responses in the T47D breast carcinoma cell line. The IL-6-type cytokines, IL-6 and oncostatin M, simultaneously inhibited cell proliferation and increased cell migration. In T47D cells, IL-6 stimulated the activation of Janus-activated kinase 1 tyrosine kinase and signal transducers and activators of transcription (STAT) 1 and STAT3 transcription factors. Expression of dominant negative STAT3 in the cells strongly reduced IL-6-mediated growth inhibition but did not prevent IL-6-induced cell migration. IL-6 treatment led to activation of the mitogen-activated protein kinase (MAPK) and the phosphatidylinositol 3'-kinase (PI3K) pathways. Inhibition of MAPK or PI3K activity reversed IL-6- and oncostatin M-stimulated migration. Because cross-talk between cytokine receptors and members of the ErbB family of receptor tyrosine kinases has been described previously, we have examined their interaction in T47D cells. Down-regulation of ErbB receptor activity, through the use of specific pharmacological inhibitors or dominant negative receptor constructs, revealed that IL-6-induced MAPK activation was largely dependent on epidermal growth factor (EGF) receptor activity, but not on ErbB-2 activity. Using a monoclonal antibody that interferes with EGF receptor-ligand interaction, we have shown that in T47D cells, IL-6 cooperates with an EGF receptor autocrine activity loop for signaling through the MAPK and PI3K pathways and for cell migration. Both the tyrosine phosphatase SHP-2 and the multisubstrate docking molecule Gab1, which are potential links between IL-6 and the MAPK/PI3K pathways, were constitutively associated with the active EGF receptor. On IL-6 stimulation, SHP-2 and Gab1 were recruited to the gp130 subunit of the IL-6 receptor and tyrosine phosphorylated, allowing downstream signaling to the MAPK and PI3K pathways. Thus, in T47D breast carcinoma cells, IL-6 acts in synergy with EGF receptor autocrine activity to signal through the MAPK/PI3K pathways. Cooperation between IL-6 and the EGF receptor in T47D breast carcinoma cells illustrates how a combination of multiple stimuli, either exogenous or endogenous, may result in synergistic cellular responses.

Use of microgravity bioreactors for development of an in vitro rat salivary gland cell culture model

NASA Technical Reports Server (NTRS)

Lewis, M. L.; Moriarity, D. M.; Campbell, P. S.

1993-01-01

During development, salivary gland (SG) cells both secrete factors which modulate cellular behavior and express specific hormone receptors. Whether SG cell growth is modulated by an autocrine epidermal growth factor (EGF) receptor-mediated signal transduction pathway is not clearly understood. SG tissue is the synthesis site for functionally distinct products including growth factors, digestive enzymes, and homeostasis maintaining factors. Historically, SG cells have proven difficult to grow and may be only maintained as limited three-dimensional ductal-type structures in collagen gels or on reconstituted basement membrane gels. A novel approach to establishing primary rat SG cultures is use of microgravity bioreactors originally designed by NASA as low-shear culture systems for predicting cell growth and differentiation in the microgravity environment of space. These completely fluid-filled bioreactors, which are oriented horizontally and rotate, have proven advantageous for Earth-based culture of three-dimensional cell assemblies, tissue-like aggregates, and glandular structures. Use of microgravity bioreactors for establishing in vitro models to investigate steroid-mediated secretion of EGF by normal SG cells may also prove useful for the investigation of cancer and other salivary gland disorders. These microgravity bioreactors promise challenging opportunities for future applications in basic and applied cell research.

Duplicated growth hormone genes in a passerine bird, the jungle crow (Corvus macrorhynchos).

PubMed

Arai, Natsumi; Iigo, Masayuki

2010-07-02

Molecular cloning, molecular phylogeny, gene structure and expression analyses of growth hormone (GH) were performed in a passerine bird, the jungle crow (Corvus macrorhynchos). Unexpectedly, duplicated GH cDNA and genes were identified and designated as GH1A and GH1B. In silico analyses identified the zebra finch orthologs. Both GH genes encode 217 amino acid residues and consist of five exons and four introns, spanning 5.2 kbp in GH1A and 4.2 kbp in GH1B. Predicted GH proteins of the jungle crow and zebra finch contain four conserved cysteine residues, suggesting duplicated GH genes are functional. Molecular phylogenetic analysis revealed that duplication of GH genes occur after divergence of the passerine lineage from the other avian orders as has been suggested from partial genomic DNA sequences of passerine GH genes. RT-PCR analyses confirmed expression of GH1A and GH1B in the pituitary gland. In addition, GH1A gene is expressed in all the tissues examined. However, expression of GH1B is confined to several brain areas and blood cells. These results indicate that the regulatory mechanisms of duplicated GH genes are different and that duplicated GH genes exert both endocrine and autocrine/paracrine functions. Copyright 2010 Elsevier Inc. All rights reserved.

Temporal Control of Transforming Growth Factor (TGF) - Betal Expression on Mammary Cell Multistep Transformation

DTIC Science & Technology

2000-10-01

phosphorylation of Smad2 tumors, EMT appears to be initiated by TGF-P produced and Smad3 at specific Erk consensus sites in the linker by peritumoral host...1243-1252. linker region of Smad2 and Smad3 , which, in turn, inhibit Smad accumula- Inhibition of autocrine TGF-j signaling, by expression of dominant...mediated mostly by TGF-P1 and TGF-j2 are potent immunosuppressants the receptor specific Smad2 and Smad3 proteins [47,48], [73]. Thus, elevated levels

Hyperestrogenemia and presence of estrogen receptors associated with an epithelial ovarian tumor of low malignant potential.

PubMed

Ben-Hur, H; Dgani, R; Insler, V; Lifschitz-Mercer, B; Blickstein, I; Mor, G; Kohen, F; Shani, A; Biran, H

1996-01-01

An 80-year-old woman presented with breast congestion, tenderness and pain. Mammography was normal. Circulating estradiol was markedly elevated, while LH and FSH were low. Pelvic examination and imaging revealed an ovarian mass which was extirpated during total abdominal hysterectomy and bilateral salpingo-oophorectomy. Histopathology revealed an ovarian mucinous cystadenocarcinoma of low malignant potential, stage 1. The tumor was positively stained for estrogen receptors. Estradiol levels returned to normal post-operatively, with a corresponding adjustment of LH/FSH. Possible autocrine steroid production is discussed.

Tumor-Secreted Autocrine Motility Factor (AMF): Casual Role in a Animal Model of Cachexia

DTIC Science & Technology

2004-08-01

83:526-531 Crown AL, Cottle K, Lightman SL, Falk S, Mohamed-Ali V, Armstrong L, Millar AB, Holly JM (2002). What is the role of the insulin-like growth...Falk S, Mohamed-Ali V, Armstrong L, Millar AB, Holly JM (2002). What is the role of the insulin-like growth factor system in the pathophysiology of...Regulation of lipolysis: natriuretic peptides and the development of cachexia. Int J Cardiol 85:125-132 Kotler DP (2000). Cachexia. Ann Intern Med 133:622-634

The contribution of growth hormone to mammary neoplasia

PubMed Central

Perry, Jo K; Mohankumar, Kumarasamypet M; Emerald, B Starling; Mertani, Hichem C; Lobie, Peter E

2008-01-01

While the effects of growth hormone (GH) on longitudinal growth are well established, the observation that GH contributes to neoplastic progression is more recent. Accumulating literature implicates GH-mediated signal transduction in the development and progression of a wide range malignancies including breast cancer. Recently autocrine human GH been demonstrated to be an orthotopically expressed oncogene for the human mammary gland. This review will highlight recent evidence linking GH and mammary carcinoma and discuss GH-antagonism as a potential therapeutic approach for treatment of breast cancer. PMID:18253708

Invasive breast carcinoma cells from patients exhibit MenaINV- and macrophage-dependent transendothelial migration

PubMed Central

Pignatelli, Jeanine; Goswami, Sumanta; Jones, Joan G.; Rohan, Thomas E.; Pieri, Evan; Chen, Xiaoming; Adler, Esther; Cox, Dianne; Maleki, Sara; Bresnick, Anne; Gertler, Frank B.; Condeelis, John S.; Oktay, Maja H.

2014-01-01

Metastasis is a complex, multistep process of cancer progression that has few treatment options. A critical event is the invasion of cancer cells into blood vessels (intravasation), through which cancer cells disseminate to distant organs. Breast cancer cells with increased abundance of Mena [an epidermal growth factor (EGF)–responsive cell migration protein] are present with macrophages at sites of intravasation, called TMEM sites (for tumor microenvironment of metastasis), in patient tumor samples. Furthermore, the density of these intravasation sites correlates with metastatic risk in patients. We found that intravasation of breast cancer cells may be prevented by blocking the signaling between cancer cells and macrophages. We obtained invasive breast ductal carcinoma cells of various subtypes by fine-needle aspiration (FNA) biopsies from patients and found that, in an in vitro transendothelial migration assay, cells that migrated through a layer of human endothelial cells were enriched for the transcript encoding MenaINV, an invasive isoform of Mena. This enhanced transendothelial migration required macrophages and occurred with all of the breast cancer subtypes. Using mouse macrophages and the human cancer cells from the FNAs, we identified paracrine and autocrine activation of colony-stimulating factor-1 receptor (CSF-1R). The paracrine or autocrine nature of the signal depended on the breast cancer cell subtype. Knocking down MenaINV or adding an antibody that blocks CSF-1R function prevented transendothelial migration. Our findings indicate that MenaINV and TMEM frequency are correlated prognostic markers and CSF-1 and MenaINV may be therapeutic targets to prevent metastasis of multiple breast cancer subtypes. PMID:25429076

WNT11 expression is induced by ERRα and β-catenin and acts in an autocrine manner to increase cancer cell migration

PubMed Central

Dwyer, Mary A.; Joseph, James; Wade, Hilary E.; Eaton, Matthew L.; Kunder, Rebecca S.; Kazmin, Dmitri; Chang, Ching-yi; McDonnell, Donald P.

2010-01-01

Elevated expression of the orphan nuclear receptor estrogen-related receptor alpha (ERRα) has been associated with a negative outcome in several cancers, although the mechanism(s) by which this receptor influences the pathophysiology of this disease and how its activity is regulated remains unknown. Using a chemical biology approach it was determined that compounds, previously shown to inhibit canonical Wnt signaling, also inhibited the transcriptional activity of ERRα. The significance of this association was revealed in a series of biochemical and genetic experiments that demonstrate that (a) ERRα, β-catenin (β-cat) and Lymphoid enhancer-binding factor-1 (LEF-1) form macromolecular complexes in cells, (b) ERRα transcriptional activity is enhanced by βcat expression and vice versa, and (c) there is a high level of overlap among genes previously shown to be regulated by ERRα or β-cat. Furthermore, silencing of ERRα and β-cat expression individually or together dramatically reduced the migratory capacity of both breast and prostate cancer cells in vitro. This increased migration could be attributed to the ERRα/β-cat dependent induction of WNT11. Specifically, using (a) conditioned media from cells overexpressing recombinant WNT11 or (b) WNT11 neutralizing antibodies, we were able to demonstrate that this protein was the key mediator of the promigratory activities of ERRα/β-cat. Together, these data provide evidence for an autocrine regulatory loop involving transcriptional upregulation of WNT11 by ERRα and β-cat that influences the migratory capacity of cancer cells. PMID:20870744

Postsynaptic Depolarization Enhances GABA Drive to Dorsomedial Hypothalamic Neurons through Somatodendritic Cholecystokinin Release.

PubMed

Crosby, Karen M; Baimoukhametova, Dinara V; Bains, Jaideep S; Pittman, Quentin J

2015-09-23

Somatodendritically released peptides alter synaptic function through a variety of mechanisms, including autocrine actions that liberate retrograde transmitters. Cholecystokinin (CCK) is a neuropeptide expressed in neurons in the dorsomedial hypothalamic nucleus (DMH), a region implicated in satiety and stress. There are clear demonstrations that exogenous CCK modulates food intake and neuropeptide expression in the DMH, but there is no information on how endogenous CCK alters synaptic properties. Here, we provide the first report of somatodendritic release of CCK in the brain in male Sprague Dawley rats. CCK is released from DMH neurons in response to repeated postsynaptic depolarizations, and acts in an autocrine fashion on CCK2 receptors to enhance postsynaptic NMDA receptor function and liberate the retrograde transmitter, nitric oxide (NO). NO subsequently acts presynaptically to enhance GABA release through a soluble guanylate cyclase-mediated pathway. These data provide the first demonstration of synaptic actions of somatodendritically released CCK in the hypothalamus and reveal a new form of retrograde plasticity, depolarization-induced potentiation of inhibition. Significance statement: Somatodendritic signaling using endocannabinoids or nitric oxide to alter the efficacy of afferent transmission is well established. Despite early convincing evidence for somatodendritic release of neurohypophysial peptides in the hypothalamus, there is only limited evidence for this mode of release for other peptides. Here, we provide the first evidence for somatodendritic release of the satiety peptide cholecystokinin (CCK) in the brain. We also reveal a new form of synaptic plasticity in which postsynaptic depolarization results in enhancement of inhibition through the somatodendritic release of CCK. Copyright © 2015 the authors 0270-6474/15/3513160-11$15.00/0.

Autocrine interleukin-23 promotes self-renewal of CD133+ ovarian cancer stem-like cells.

PubMed

Wang, Dan; Xiang, Tong; Zhao, Zhongquan; Lin, Kailong; Yin, Pin; Jiang, Lupin; Liang, Zhiqing; Zhu, Bo

2016-11-15

Cancer stem cells (CSCs) are a group of cells which possess the ability of self-renewing and unlimited proliferation. And these CSCs are thought to be the cause of metastasis, recurrence and resistance. Recent study has found that pro-inflammatory cytokine and chemotactic factor mediate the self-renewing and differentiation of most of CSCs. Thus we speculate that ovarian cancer stem cells (OCSCs) can also maintain the ability of self-renewing and differentiation by releasing inflammatory factor. This report we discuss the biological characteristics and the specific molecular mechanism mediated by interleukin-23 (IL-23) and its receptor on the self-renewing of OCSCs. We found that OCSCs had high expression of IL-23 and IL-23R. IL-23 could promote the self-renewal ability of OCSCs and played a very important role to maintain the stable expression of stem cell markers in vitro. Moreover, we verified that IL-23 could maintain the potential tumorigenic of OCSCs in vivo and mediate the self-renewal ability and the formation of tumor in OCSCs by activating the signal pathways of STAT3 and NF-κB. In addition, human low differentiation tissues showed overexpression of IL-23. And IL-23 positively correlated to the expression level of CD133, Nanog and Oct4. In conclusion, Our discoveries demonstrate that autocrine IL-23 contribute to ovarian cancer malignancy through promoting the self-renewal of CD133+ ovarian cancer stem-like cells, and this suggests that IL-23 and its signaling pathway might serve as therapeutic targets for the treatment of ovarian cancer.

Bombesin related peptides/receptors and their promising therapeutic roles in cancer imaging, targeting and treatment

PubMed Central

Moreno, Paola; Ramos-Álvarez, Irene; Moody, Terry W.; Jensen, Robert T.

2016-01-01

Introduction Despite remarkable advances in tumor treatment, many patients still die from common tumors (breast, prostate, lung, CNS, colon, and pancreas), and thus, new approaches are needed. Many of these tumors synthesize bombesin (Bn)-related peptides and over-express their receptors (BnRs), hence functioning as autocrine-growth-factors. Recent studies support the conclusion that Bn-peptides/BnRs are well-positioned for numerous novel antitumor treatments, including interrupting autocrine-growth via the use of over-expressed receptors for imaging and targeting cytotoxic-compounds, either by direct-coupling or combined with nanoparticle-technology. Areas covered The unique ability of common neoplasms to synthesize, secrete, and show a growth/proliferative/differentiating response due to BnR over-expression, is reviewed, both in general and with regard to the most frequently investigated neoplasms (breast, prostate, lung, and CNS). Particular attention is paid to advances in the recent years. Also considered are the possible therapeutic approaches to the growth/differentiation effect of Bn-peptides, as well as the therapeutic implication of the frequent BnR over-expression for tumor-imaging and/or targeted-delivery. Expert opinion Given that Bn-related-peptides/BnRs are so frequently ectopically-expressed by common tumors, which are often malignant and become refractory to conventional treatments, therapeutic interventions using novel approaches to Bn-peptides and receptors are being explored. Of particular interest is the potential of reproducing BnRs in common tumors, such as the recent success of utilizing overexpression of somatostatin-receptors by neuroendocrine-tumors to provide the most sensitive imaging methods and targeted delivery of cytotoxic-compounds. PMID:26981612

Involvement of human decidual cell-expressed tissue factor in uterine hemostasis and abruption

PubMed Central

Lockwood, C.J.; Paidas, M.; Murk, W.K.; Kayisli, U.A.; Gopinath, A.; Krikun, G.; Huang, S.J.; Schatz, F.

2009-01-01

Vascular injury increases access and binding of plasma-derived factor VII to perivascular cell membrane-bound tissue factor (TF). The resulting TF/VIIa complex promotes hemostasis by cleaving pro-thrombin to thrombin leading to the fibrin clot. In human pregnancy, decidual cell-expressed TF prevents decidual hemorrhage (abruption). During placentation, trophoblasts remodel decidual spiral arteries into high conductance vessels. Shallow trophoblast invasion impedes decidual vascular conversion, producing an inadequate uteroplacental blood flow that elicits abruption-related placental ischemia. Thrombin induces several biological effects via cell surface protease activated receptors. In first trimester human DCs thrombin increases synthesis of sFlt-1, which elicits placental ischemia by impeding angiogenesis-related decidual vascular remodeling. During pregnacy, the fibrillar collagen-rich amnion and choriodecidua extracellular matrix (ECM) provides greater than additive tensile strength and structural integrity. Thrombin acts as an autocrine/paracrine mediator that degrades these ECMs by augmenting decidual cell expression of: 1) matrix metalloproteinases and 2) interleukin-8, a key mediator of abruption-associated decidual infiltration of neutrophils, which express several ECM degrading proteases. Our recent observations that: 1) among the cell types at the maternal fetal interface at term TF expression is highest in decidual cells indicates that this TF meets the hemostatic demands of labor and delivery; 2) TF expression in cultured term decidual cells is enhanced by progestin and thrombin suggest that maintenance of elevated circulating progesterone at term provides hemostatic protection, whereas abruption-generated thrombin can act in autocrine/paracrine fashion on DCs to promote hemostasis via enhanced TF expression. PMID:19720393

Platelet-derived growth factor-receptor alpha strongly inhibits melanoma growth in vitro and in vivo.

PubMed

Faraone, Debora; Aguzzi, Maria Simona; Toietta, Gabriele; Facchiano, Angelo M; Facchiano, Francesco; Magenta, Alessandra; Martelli, Fabio; Truffa, Silvia; Cesareo, Eleonora; Ribatti, Domenico; Capogrossi, Maurizio C; Facchiano, Antonio

2009-08-01

Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs) is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Ralpha may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Ralpha respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Ralpha. Proliferation was rescued by PDGF-Ralpha inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Ralpha mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Ralpha was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Ralpha show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Balpha and a marked increase of p38gamma, mitogen-activated protein kinase kinase 3, and signal regulatory protein alpha1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Ralpha reached a significant 70% inhibition of primary melanoma growth (P < .001) and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Ralpha strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control.

THE OXYTOCIN-BONE AXIS

PubMed Central

Colaianni, G.; Tamma, R.; Di Benedetto, A.; Yuen, T.; Sun, L.; Zaidi, M.; Zallone, A.

2014-01-01

We recently demonstrated a direct action of oxytocin (OT) on skeletal homeostasis mainly mediated through stimulation of osteoblasts (OBs) formation and through the reciprocal modulation of osteoclast (OCs) formation and function. Thus, mice lacking the hormone or its receptor develop a low turnover osteoporosis that worsens with age in both sexes. The skeleton of OT and OT receptor (Oxtr) null mice display a pronounced decrease in vertebral and femoral trabecular volume. At cellular level OBs from OT−/− and Oxtr−/− mice exhibit lower mineralization activity and, at mRNA level, all master genes for osteoblast differentiation are down regulated. Moreover, OT has dual effects on OCs: it increases osteoclast formation both directly, by activating NF-kB and MAP kinase signaling, and indirectly, through the up-regulation of RANK-L synthesis by OBs. On the other hand, it inhibits bone resorption by triggering cytosolic Ca2+ release and nitric oxide synthesis in mature OCs. OT is locally produced by osteoblasts acting as paracrine-autocrine regulator of bone formation modulated by estrogens. The estrogen signal involved in this feed forward circuit is non genomic, since it requires an intact MAPK kinase signal transduction pathway, instead of the classical nuclear translocation of estrogen receptor. The ability of estrogen to increase bone mass in vivo is to an extent OTR-dependent. Thus Oxtr−/− mice injected 17β-estradiol did not show any effects on bone formation parameters, while the same treatment increases trabecular and cortical bone in wild type mice. An intact OT autocrine-paracrine circuit seems to be essential for optimal skeletal remodeling. PMID:24219627

A minireview of E4BP4/NFIL3 in heart failure.

PubMed

Velmurugan, Bharath Kumar; Chang, Ruey-Lin; Marthandam Asokan, Shibu; Chang, Chih-Fen; Day, Cecilia-Hsuan; Lin, Yueh-Min; Lin, Yuan-Chuan; Kuo, Wei-Wen; Huang, Chih-Yang

2018-06-01

Heart failure (HF) remains a major cause of morbidity and mortality worldwide. The primary cause identified for HF is impaired left ventricular myocardial function, and clinical manifestations may lead to severe conditions like pulmonary congestion, splanchnic congestion, and peripheral edema. Development of new therapeutic strategies remains the need of the hour for controlling the problem of HF worldwide. Deeper insights into the molecular mechanisms involved in etiopathology of HF indicate the significant role of calcium signaling, autocrine signaling pathways, and insulin-like growth factor-1 signaling that regulates the physiologic functions of heart growth and development such as contraction, metabolism, hypertrophy, cytokine signaling, and apoptosis. In view of these facts, a transcription factor (TF) regulating the myriad of these signaling pathways may prove as a lead candidate for development of therapeutics. Adenovirus E4 promoter-binding protein (E4BP4), also known as nuclear-factor, interleukin 3 regulated (NFIL3), a type of basic leucine zipper TF, is known to regulate the signaling processes involved in the functioning of heart. The current review discusses about the expression, structure, and functional role of E4BP4 in signaling processes with emphasis on calcium signaling mechanisms, autocrine signaling, and insulin-like growth factor II receptor-mediated processes regulated by E4BP4 that may regulate the pathogenesis of HF. We propose that E4BP4, being the critical component for the regulation of the above signaling processes, may serve as a novel therapeutic target for HF, and scientific investigations are merited in this direction. © 2018 Wiley Periodicals, Inc.

Proliferation of NS0 cells in protein-free medium: the role of cell-derived proteins, known growth factors and cellular receptors.

PubMed

Spens, Erika; Häggström, Lena

2009-05-20

NS0 cells proliferate without external supply of growth factors in protein-free media. We hypothesize that the cells produce their own factors to support proliferation. Understanding the mechanisms behind this autocrine regulation of proliferation may open for the novel approaches to improve animal cell processes. The following proteins were identified in NS0 conditioned medium (CM): cyclophilin A, cyclophilin B (CypB), cystatin C, D-dopachrome tautomerase, IL-25, isopentenyl-diphosphate delta-isomerase, macrophage migration inhibitory factor (MIF), beta(2)-microglobulin, Niemann pick type C2, secretory leukocyte protease inhibitor, thioredoxin-1, TNF-alpha, tumour protein translationally controlled 1 and ubiquitin. Further, cDNA microarray analysis indicated that the genes for IL-11, TNF receptor 6, TGF-beta receptor 1 and the IFN-gamma receptor were transcribed. CypB, IFN-alpha/beta/gamma, IL-11, IL-25, MIF, TGF-beta and TNF-alpha as well as the known growth factors EGF, IGF-I/II, IL-6, leukaemia inhibitory factor and oncostatin M (OSM) were excluded as involved in autocrine regulation of NS0 cell proliferation. The receptors for TGF-beta, IGF and OSM are however present in NS0 cell membranes since TGF-beta(1) caused cell death, and IGF-I/II and OSM improved cell growth. Even though no ligand was found, the receptor subunit gp130, active in signal transduction of the IL-6 like proteins, was shown to be essential for NS0 cells as demonstrated by siRNA gene silencing.

Muscle-derived collagen XIII regulates maturation of the skeletal neuromuscular junction.

PubMed

Latvanlehto, Anne; Fox, Michael A; Sormunen, Raija; Tu, Hongmin; Oikarainen, Tuomo; Koski, Anu; Naumenko, Nikolay; Shakirzyanova, Anastasia; Kallio, Mika; Ilves, Mika; Giniatullin, Rashid; Sanes, Joshua R; Pihlajaniemi, Taina

2010-09-15

Formation, maturation, stabilization, and functional efficacy of the neuromuscular junction (NMJ) are orchestrated by transsynaptic and autocrine signals embedded within the synaptic cleft. Here, we demonstrate that collagen XIII, a nonfibrillar transmembrane collagen, is another such signal. We show that collagen XIII is expressed by muscle and its ectodomain can be proteolytically shed into the extracellular matrix. The collagen XIII protein was found present in the postsynaptic membrane and synaptic basement membrane. To identify a role for collagen XIII at the NMJ, mice were generated lacking this collagen. Morphological and ultrastructural analysis of the NMJ revealed incomplete adhesion of presynaptic and postsynaptic specializations in collagen XIII-deficient mice of both genders. Strikingly, Schwann cells erroneously enwrapped nerve terminals and invaginated into the synaptic cleft, resulting in a decreased contact surface for neurotransmission. Consistent with morphological findings, electrophysiological studies indicated both postsynaptic and presynaptic defects in Col13a1(-/-) mice, such as decreased amplitude of postsynaptic potentials, diminished probabilities of spontaneous release and reduced readily releasable neurotransmitter pool. To identify the role of collagen XIII at the NMJ, shed ectodomain of collagen XIII was applied to cultured myotubes, and it was found to advance acetylcholine receptor (AChR) cluster maturation. Together with the delay in AChR cluster development observed in collagen XIII-deficient mutants in vivo, these results suggest that collagen XIII plays an autocrine role in postsynaptic maturation of the NMJ. Altogether, the results presented here reveal that collagen XIII is a novel muscle-derived cue necessary for the maturation and function of the vertebrate NMJ.

Autocrine IL-10 activation of the STAT3 pathway is required for pathological macrophage differentiation in polycystic kidney disease

PubMed Central

Peda, Jacqueline D.; Salah, Sally M.; Wallace, Darren P.; Fields, Patrick E.; Grantham, Connor J.; Fields, Timothy A.

2016-01-01

ABSTRACT Polycystic kidney disease (PKD) is characterized by slow expansion of fluid-filled cysts derived from tubules within the kidney. Cystic expansion results in injury to surrounding parenchyma and leads to inflammation, scarring and ultimately loss of renal function. Macrophages are a key element in this process, promoting cyst epithelial cell proliferation, cyst expansion and disease progression. Previously, we have shown that the microenvironment established by cystic epithelial cells can ‘program’ macrophages, inducing M2-like macrophage polarization that is characterized by expression of markers that include Arg1 and Il10. Here, we functionally characterize these macrophages, demonstrating that their differentiation enhances their ability to promote cyst cell proliferation. This observation indicates a model of reciprocal pathological interactions between cysts and the innate immune system: cyst epithelial cells promote macrophage polarization to a phenotype that, in turn, is especially efficient in promoting cyst cell proliferation and cyst growth. To better understand the genesis of this macrophage phenotype, we examined the role of IL-10, a regulatory cytokine shown to be important for macrophage-stimulated tissue repair in other settings. Herein, we show that the acquisition of the pathological macrophage phenotype requires IL-10 secretion by the macrophages. Further, we demonstrate a requirement for IL-10-dependent autocrine activation of the STAT3 pathway. These data suggest that the IL-10 pathway in macrophages plays an essential role in the pathological relationship between cysts and the innate immune system in PKD, and thus could be a potential therapeutic target. PMID:27491076

Autocrine VEGF–VEGFR2–Neuropilin-1 signaling promotes glioma stem-like cell viability and tumor growth

PubMed Central

Hamerlik, Petra; Lathia, Justin D.; Rasmussen, Rikke; Wu, Qiulian; Bartkova, Jirina; Lee, MyungHee; Moudry, Pavel; Bartek, Jiri; Fischer, Walter; Lukas, Jiri

2012-01-01

Although vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) is traditionally regarded as an endothelial cell protein, evidence suggests that VEGFRs may be expressed by cancer cells. Glioblastoma multiforme (GBM) is a lethal cancer characterized by florid vascularization and aberrantly elevated VEGF. Antiangiogenic therapy with the humanized VEGF antibody bevacizumab reduces GBM tumor growth; however, the clinical benefits are transient and invariably followed by tumor recurrence. In this study, we show that VEGFR2 is preferentially expressed on the cell surface of the CD133+ human glioma stem-like cells (GSCs), whose viability, self-renewal, and tumorigenicity rely, at least in part, on signaling through the VEGF-VEGFR2–Neuropilin-1 (NRP1) axis. We find that the limited impact of bevacizumab-mediated VEGF blockage may reflect ongoing autocrine signaling through VEGF–VEGFR2–NRP1, which is associated with VEGFR2–NRP1 recycling and a pool of active VEGFR2 within a cytosolic compartment of a subset of human GBM cells. Whereas bevacizumab failed to inhibit prosurvival effects of VEGFR2-mediated signaling, GSC viability under unperturbed or radiation-evoked stress conditions was attenuated by direct inhibition of VEGFR2 tyrosine kinase activity and/or shRNA-mediated knockdown of VEGFR2 or NRP1. We propose that direct inhibition of VEGFR2 kinase may block the highly dynamic VEGF–VEGFR2–NRP1 pathway and inspire a GBM treatment strategy to complement the currently prevalent ligand neutralization approach. PMID:22393126

Autocrine feedback inhibition of plateau potentials terminates phasic bursts in magnocellular neurosecretory cells of the rat supraoptic nucleus

PubMed Central

Brown, Colin H; Bourque, Charles W

2004-01-01

Phasic activity in magnocellular neurosecretory cells is characterized by alternating periods of activity (bursts) and silence. During phasic bursts, action potentials are superimposed on plateau potentials that are generated by summation of depolarizing after-potentials. Dynorphin is copackaged in vasopressin neurosecretory vesicles that are exocytosed from magnocellular neurosecretory cell dendrites and terminals, and both peptides have been implicated in the generation of phasic activity. Here we show that somato-dendritic dynorphin release terminates phasic bursts by autocrine inhibition of plateau potentials in magnocellular neurosecretory cells recorded intracellularly from hypothalamic explants using sharp electrodes. Conditioning spike trains caused an activity-dependent reduction of depolarizing after-potential amplitude that was partially reversed by α-latrotoxin (which depletes neurosecretory vesicles) and by nor-binaltorphimine (κ-opioid receptor antagonist), but not by an oxytocin/vasopressin receptor antagonist or a μ-opioid receptor antagonist, indicating that activity-dependent inhibition of depolarizing after-potentials requires exocytosis of an endogenous κ-opioid peptide. κ-Opioid inhibition of depolarizing after-potentials was not mediated by actions on evoked after-hyperpolarizations since these were not affected by κ-opioid receptor agonists or antagonists. Evoked bursts were prolonged by antagonism of κ-opioid receptors with nor-binaltorphimine and by depletion of neurosecretory vesicles by α-latrotoxin, becoming everlasting in ∼50% of cells. Finally, spontaneously active neurones exposed to nor-binaltorphimine switched from phasic to continuous firing as plateau potentials became non-inactivating. Thus, dynorphin coreleased with vasopressin generates phasic activity through activity-dependent feedback inhibition of plateau potentials in magnocellular neurosecretory cells. PMID:15107473

Dectin-1/2–induced autocrine PGE2 signaling licenses dendritic cells to prime Th2 responses

PubMed Central

Kaisar, Maria M. M.; Jónasdóttir, Hulda S.; van der Ham, Alwin J.; Pelgrom, Leonard R.; Schramm, Gabriele; Layland, Laura E.; Sancho, David; Prazeres da Costa, Clarissa; Giera, Martin; Yazdanbakhsh, Maria

2018-01-01

The molecular mechanisms through which dendritic cells (DCs) prime T helper 2 (Th2) responses, including those elicited by parasitic helminths, remain incompletely understood. Here, we report that soluble egg antigen (SEA) from Schistosoma mansoni, which is well known to drive potent Th2 responses, triggers DCs to produce prostaglandin E2 (PGE2), which subsequently—in an autocrine manner—induces OX40 ligand (OX40L) expression to license these DCs to drive Th2 responses. Mechanistically, SEA was found to promote PGE2 synthesis through Dectin-1 and Dectin-2, and via a downstream signaling cascade involving spleen tyrosine kinase (Syk), extracellular signal-regulated kinase (ERK), cytosolic phospholipase A2 (cPLA2), and cyclooxygenase 1 and 2 (COX-1 and COX-2). In addition, this pathway was activated independently of the actions of omega-1 (ω-1), a previously described Th2-priming glycoprotein present in SEA. These findings were supported by in vivo murine data showing that ω-1–independent Th2 priming by SEA was mediated by Dectin-2 and Syk signaling in DCs. Finally, we found that Dectin-2−/−, and to a lesser extent Dectin-1−/− mice, displayed impaired Th2 responses and reduced egg-driven granuloma formation following S. mansoni infection, highlighting the physiological importance of this pathway in Th2 polarization during a helminth infection. In summary, we identified a novel pathway in DCs involving Dectin-1/2-Syk-PGE2-OX40L through which Th2 immune responses are induced. PMID:29668708

IFNβ/TNFα synergism induces a non-canonical STAT2/IRF9-dependent pathway triggering a novel DUOX2 NADPH Oxidase-mediated airway antiviral response

PubMed Central

Fink, Karin; Martin, Lydie; Mukawera, Esperance; Chartier, Stéfany; De Deken, Xavier; Brochiero, Emmanuelle; Miot, Françoise; Grandvaux, Nathalie

2013-01-01

Airway epithelial cells are key initial innate immune responders in the fight against respiratory viruses, primarily via the secretion of antiviral and proinflammatory cytokines that act in an autocrine/paracrine fashion to trigger the establishment of an antiviral state. It is currently thought that the early antiviral state in airway epithelial cells primarily relies on IFNβ secretion and the subsequent activation of the interferon-stimulated gene factor 3 (ISGF3) transcription factor complex, composed of STAT1, STAT2 and IRF9, which regulates the expression of a panoply of interferon-stimulated genes encoding proteins with antiviral activities. However, the specific pathways engaged by the synergistic action of different cytokines during viral infections, and the resulting physiological outcomes are still ill-defined. Here, we unveil a novel delayed antiviral response in the airways, which is initiated by the synergistic autocrine/paracrine action of IFNβ and TNFα, and signals through a non-canonical STAT2- and IRF9-dependent, but STAT1-independent cascade. This pathway ultimately leads to the late induction of the DUOX2 NADPH oxidase expression. Importantly, our study uncovers that the development of the antiviral state relies on DUOX2-dependent H2O2 production. Key antiviral pathways are often targeted by evasion strategies evolved by various pathogenic viruses. In this regard, the importance of the novel DUOX2-dependent antiviral pathway is further underlined by the observation that the human respiratory syncytial virus is able to subvert DUOX2 induction. PMID:23545780

Crucial role of interleukin-4 in the survival of colon cancer stem cells.

PubMed

Francipane, Maria Giovanna; Alea, Mileidys Perez; Lombardo, Ylenia; Todaro, Matilde; Medema, J P; Stassi, Giorgio

2008-06-01

Colon tumors may be maintained by a rare fraction of cancer stem-like cells (CSC) that express the cell surface marker CD133. Self-renewing CSCs exhibit relatively greater resistance to clinical cytotoxic therapies and recent work suggests that this resistance may be mediated in part by an autocrine response to the immune cytokine interleukin 4 (IL-4). Blocking IL-4 signaling can sensitize CSCs to apoptotic stimuli and increase the in vivo efficacy of cytotoxic therapy. These findings suggest that inhibitors of IL-4 signaling may offer a new therapeutic tool in colon carcinoma.

In response to: Unsolved enigma of atrial myxoma with biventricular dysfunction.

PubMed

Dixit, Aanchal; Tewari, Prabhat; Soori, Rashmi; Agarwal, Surendra Kumar

2018-01-01

Thanks to Raut et al.[1] for appreciating our efforts in managing the case of biatrial myxomas. A brief discussion is warranted here on the types, size of cardiac myxomas, interleukin 6 (IL-6) levels, left ventricle (LV) dysfunction, and their relation. IL-6 is a pleiotropic cytokine with a variety of biologic activities, including differentiation of B cell, thymocytes, and T cells; activation of macrophages; and stimulation of hepatocyte to produce acute-phase proteins such as C-reactive protein.[2],[3] It is also said to have paracrine, endocrine, and autocrine growth functions.[3].

Autocrine and Paracrine Hh Signaling Regulate Prostate Development

DTIC Science & Technology

2010-09-01

Rev. Mol. Cell. Biol. 6, 306–317 7. Wang, B. E., Shou, J., Ross, S., Koeppen, H., De Sauvage, F. J., and Gao, W. Q. (2003) J. Biol. Chem. 278, 18506...and Placzek, M. (2006) Nat. Rev. Genet. 7, 841–850 13. Callahan, C. A., Ofstad, T., Horng, L.,Wang, J. K., Zhen, H. H., Coulombe , P. A., and Oro, A. E...Albig, A. R., and Schiemann, W. P. (2005)Mol. Biol. Cell 16, 609–625 45. Olsen, M. W., Ley , C. D., Junker, N., Hansen, A. J., Lund, E. L., and Krist

Mechanisms of Progranulin Action and Regulation in Genitourinary Cancers.

PubMed

Tanimoto, Ryuta; Lu, Kuojung G; Xu, Shi-Qiong; Buraschi, Simone; Belfiore, Antonino; Iozzo, Renato V; Morrione, Andrea

2016-01-01

The growth factor progranulin has emerged in recent years as a critical regulator of transformation in several cancer models, including breast cancer, glioblastomas, leukemias, and hepatocellular carcinomas. Several laboratories, including ours, have also demonstrated an important role of progranulin in several genitourinary cancers, including ovarian, endometrial, cervical, prostate, and bladder tumors, where progranulin acts as an autocrine growth factor thereby modulating motility and invasion of transformed cells. In this review, we will focus on the mechanisms of action and regulation of progranulin signaling in genitourinary cancers with a special emphasis on prostate and bladder tumors.

Mechanisms of Progranulin Action and Regulation in Genitourinary Cancers

PubMed Central

Tanimoto, Ryuta; Lu, Kuojung G.; Xu, Shi-Qiong; Buraschi, Simone; Belfiore, Antonino; Iozzo, Renato V.; Morrione, Andrea

2016-01-01

The growth factor progranulin has emerged in recent years as a critical regulator of transformation in several cancer models, including breast cancer, glioblastomas, leukemias, and hepatocellular carcinomas. Several laboratories, including ours, have also demonstrated an important role of progranulin in several genitourinary cancers, including ovarian, endometrial, cervical, prostate, and bladder tumors, where progranulin acts as an autocrine growth factor thereby modulating motility and invasion of transformed cells. In this review, we will focus on the mechanisms of action and regulation of progranulin signaling in genitourinary cancers with a special emphasis on prostate and bladder tumors. PMID:27512385

Purines and Neuronal Excitability: Links to the Ketogenic Diet

PubMed Central

Masino, SA; Kawamura, M; Ruskin, DN; Geiger, JD; Boison, D

2011-01-01

ATP and adenosine are purines that play dual roles in cell metabolism and neuronal signaling. Acting at the A1 receptor (A1R) subtype, adenosine acts directly on neurons to inhibit excitability and is a powerful endogenous neuroprotective and anticonvulsant molecule. Previous research showed an increase in ATP and other cell energy parameters when an animal is administered a ketogenic diet, an established metabolic therapy to reduce epileptic seizures, but the relationship among purines, neuronal excitability and the ketogenic diet was unclear. Recent work in vivo and in vitro tested the specific hypothesis that adenosine acting at A1Rs is a key mechanism underlying the success of ketogenic diet therapy and yielded direct evidence linking A1Rs to the antiepileptic effects of a ketogenic diet. Specifically, an in vitro mimic of a ketogenic diet revealed an A1R-dependent metabolic autocrine hyperpolarization of hippocampal neurons. In parallel, applying the ketogenic diet in vivo to transgenic mouse models with spontaneous electrographic seizures revealed that intact A1Rs are necessary for the seizure-suppressing effects of the diet. This is the first direct in vivo evidence linking A1Rs to the antiepileptic effects of a ketogenic diet. Other predictions of the relationship between purines and the ketogenic diet are discussed. Taken together, recent research on the role of purines may offer new opportunities for metabolic therapy and insight into its underlying mechanisms. PMID:21880467

IL-11 is a crucial determinant of cardiovascular fibrosis

PubMed Central

Schafer, Sebastian; Viswanathan, Sivakumar; Widjaja, Anissa A.; Lim, Wei-Wen; Moreno-Moral, Aida; DeLaughter, Daniel M.; Ng, Benjamin; Patone, Giannino; Chow, Kingsley; Khin, Ester; Tan, Jessie; Chothani, Sonia P.; Ye, Lei; Rackham, Owen J. L.; Ko, Nicole S. J.; Sahib, Norliza E.; Pua, Chee Jian; Zhen, Nicole T. G.; Xie, Chen; Wang, Mao; Maatz, Henrike; Lim, Shiqi; Saar, Kathrin; Blachut, Susanne; Petretto, Enrico; Schmidt, Sabine; Putoczki, Tracy; Guimarães-Camboa, Nuno; Wakimoto, Hiroko; van Heesch, Sebastiaan; Sigmundsson, Kristmundur; Lim, See L.; Soon, Jia L.; Chao, Victor T. T.; Chua, Yeow L.; Tan, Teing E.; Evans, Sylvia M.; Loh, Yee J.; Jamal, Muhammad H.; Ong, Kim K.; Chua, Kim C.; Ong, Boon-Hean; Chakaramakkil, Mathew J.; Seidman, Jonathan G.; Seidman, Christine E.; Hubner, Norbert; Sin, Kenny Y. K.; Cook, Stuart A.

2018-01-01

Fibrosis is a common pathology in cardiovascular disease1. In the heart, fibrosis causes mechanical and electrical dysfunction1,2 and in the kidney, it predicts the onset of renal failure3. Transforming growth factor β1 (TGFβ1) is the principal pro-fibrotic factor4,5, but its inhibition is associated with side effects due to its pleiotropic roles6,7. We hypothesized that downstream effectors of TGFβ1 in fibroblasts could be attractive therapeutic targets and lack upstream toxicity. Here we show, using integrated imaging–genomics analyses of primary human fibroblasts, that upregulation of interleukin-11 (IL-11) is the dominant transcriptional response to TGFβ1 exposure and required for its pro-fibrotic effect. IL-11 and its receptor (IL11RA) are expressed specifically in fibroblasts, in which they drive non-canonical, ERK-dependent autocrine signalling that is required for fibrogenic protein synthesis. In mice, fibroblast-specific Il11 transgene expression or Il-11 injection causes heart and kidney fibrosis and organ failure, whereas genetic deletion of Il11ra1 protects against disease. Therefore, inhibition of IL-11 prevents fibroblast activation across organs and species in response to a range of important pro-fibrotic stimuli. These results reveal a central role of IL-11 in fibrosis and we propose that inhibition of IL-11 is a potential therapeutic strategy to treat fibrotic diseases. PMID:29160304

Autocrine class 3 semaphorin system regulates slit diaphragm proteins and podocyte survival.

PubMed

Guan, F; Villegas, G; Teichman, J; Mundel, P; Tufro, A

2006-05-01

Class 3 semaphorins are guidance proteins that play crucial roles during development. Semaphorins 3A (sema 3A) and 3F are expressed by podocytes in vivo throughout ontogeny and their function is unknown. Here we examined the expression of class 3 semaphorins (3A, 3B, 3C, 3D, 3E, and 3F) and their receptors (neuropilins 1 and 2, plexins A1, A2, A3, B2, and D1) in undifferentiated and differentiated mouse podocytes using reverse transcriptase-polymerase chain reaction (RT-PCR). All class 3 semaphorins, neuropilins 1 and 2 are expressed by undifferentiated and differentiated podocytes at similar levels. Differentiated podocytes expressed 2-4-fold higher plexin A1, A2, and A3 mRNA levels than undifferentiated podocytes. To examine semaphorin regulation, we exposed podocytes to recombinant sema 3A. Sema 3A decreased semaphorin 3B, plexin A1, A3, and D1 >/=50% and reduced plexin A2 mRNA to undetectable levels. To identify sema 3A function in podocytes, we examined whether sema 3A regulates slit diaphragm proteins and podocyte survival. Sema 3A induced a dose-response podocin downregulation and decreased its interaction with CD2-associated protein and nephrin, as determined by Western analysis and co-immunoprecipitation. To evaluate sema 3A role in podocyte survival, we quantified podocyte apoptosis using a caspase 3 activity marker. Sema 3A induced a 10-fold increase in podocyte apoptosis and significantly decreased the activity of the Akt survival pathway. Our data indicate that (1) immortalized podocytes in culture have a functional autocrine semaphorin system that is regulated by differentiation and ligand availability; (2) sema 3A signaling regulates the expression and interactions of slit-diaphragm proteins and decreases podocyte survival.

Microsomal Prostaglandin E Synthase-1 Facilitates an Intercellular Interaction between CD4⁺ T Cells through IL-1β Autocrine Function in Experimental Autoimmune Encephalomyelitis.

PubMed

Takemiya, Takako; Takeuchi, Chisen; Kawakami, Marumi

2017-12-19

Microsomal prostaglandin synthetase-1 (mPGES-1) is an inducible terminal enzyme that produces prostaglandin E₂ (PGE₂). In our previous study, we investigated the role of mPGES-1 in the inflammation and demyelination observed in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, using mPGES - 1 -deficient ( mPGES-1 -/- ) and wild-type (wt) mice. We found that mPGES-1 facilitated inflammation, demyelination, and paralysis and was induced in vascular endothelial cells and macrophages and microglia around inflammatory foci. Here, we investigated the role of interleukin-1β (IL-1β) in the intercellular mechanism stimulated by mPGES-1 in EAE spinal cords in the presence of inflammation. We found that the area invaded by CD4-positive (CD4⁺) T cells was extensive, and that PGE₂ receptors EP1-4 were more induced in activated CD4⁺ T cells of wt mice than in those of mPGES - 1 -/- mice. Moreover, IL-1β and IL-1 receptor 1 (IL-1r1) were produced by 65% and 48% of CD4⁺ T cells in wt mice and by 44% and 27% of CD4⁺ T cells in mPGES-1 -/- mice. Furthermore, interleukin-17 (IL-17) was released from the activated CD4⁺ T cells. Therefore, mPGES-1 stimulates an intercellular interaction between CD4⁺ T cells by upregulating the autocrine function of IL-1β in activated CD4⁺ T cells, which release IL-17 to facilitate axonal and myelin damage in EAE mice.

The chemokine receptor CXCR3 and its splice variant are expressed in human airway epithelial cells.

PubMed

Kelsen, Steven G; Aksoy, Mark O; Yang, Yi; Shahabuddin, Syed; Litvin, Judith; Safadi, Fayez; Rogers, Thomas J

2004-09-01

Activation of the chemokine receptor CXCR3 by its cognate ligands induces several differentiated cellular responses important to the growth and migration of a variety of hematopoietic and structural cells. In the human respiratory tract, human airway epithelial cells (HAEC) release the CXCR3 ligands Mig/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11. Simultaneous expression of CXCR3 by HAEC would have important implications for the processes of airway inflammation and repair. Accordingly, in the present study we sought to determine whether HAEC also express the classic CXCR3 chemokine receptor CXCR3-A and its splice variant CXCR3-B and hence may respond in autocrine fashion to its ligands. We found that cultured HAEC (16-HBE and tracheocytes) constitutively expressed CXCR3 mRNA and protein. CXCR3 mRNA levels assessed by expression array were approximately 35% of beta-actin expression. In contrast, CCR3, CCR4, CCR5, CCR8, and CX3CR1 were <5% beta-actin. Both CXCR3-A and -B were expressed. Furthermore, tracheocytes freshly harvested by bronchoscopy stained positively for CXCR3 by immunofluorescence microscopy, and 68% of cytokeratin-positive tracheocytes (i.e., the epithelial cell population) were positive for CXCR3 by flow cytometry. In 16-HBE cells, CXCR3 receptor density was approximately 78,000 receptors/cell when assessed by competitive displacement of 125I-labeled IP-10/CXCL10. Finally, CXCR3 ligands induced chemotactic responses and actin reorganization in 16-HBE cells. These findings indicate constitutive expression by HAEC of a functional CXC chemokine receptor, CXCR3. Our data suggest the possibility that autocrine activation of CXCR3 expressed by HAEC may contribute to airway inflammation and remodeling in obstructive lung disease by regulating HAEC migration.

Autocrine effect of Zn²⁺ on the glucose-stimulated insulin secretion.

PubMed

Slepchenko, Kira G; Daniels, Nigel A; Guo, Aili; Li, Yang V

2015-09-01

It is well known that zinc (Zn(2+)) is required for the process of insulin biosynthesis and the maturation of insulin secretory granules in pancreatic beta (β)-cells, and that changes in Zn(2+) levels in the pancreas have been found to be associated with diabetes. Glucose-stimulation causes a rapid co-secretion of Zn(2+) and insulin with similar kinetics. However, we do not know whether Zn(2+) regulates insulin availability and secretion. Here we investigated the effect of Zn(2+) on glucose-stimulated insulin secretion (GSIS) in isolated mouse pancreatic islets. Whereas Zn(2+) alone (control) had no effect on the basal secretion of insulin, it significantly inhibited GSIS. The application of CaEDTA, by removing the secreted Zn(2+) from the extracellular milieu of the islets, resulted in significantly increased GSIS, suggesting an overall inhibitory role of secreted Zn(2+) on GSIS. The inhibitory action of Zn(2+) was mostly mediated through the activities of KATP/Ca(2+) channels. Furthermore, during brief paired-pulse glucose-stimulated Zn(2+) secretion (GSZS), Zn(2+) secretion following the second pulse was significantly attenuated, probably by the secreted endogenous Zn(2+) after the first pulse. Such an inhibition on Zn(2+) secretion following the second pulse was completely reversed by Zn(2+) chelation, suggesting a negative feedback mechanism, in which the initial glucose-stimulated Zn(2+) release inhibits subsequent Zn(2+) secretion, subsequently inhibiting insulin co-secretion as well. Taken together, these data suggest a negative feedback mechanism on GSZS and GSIS by Zn(2+) secreted from β-cells, and the co-secreted Zn(2+) may act as an autocrine inhibitory modulator.

Expression of platelet-derived growth factor BB, erythropoietin and erythropoietin receptor in canine and feline osteosarcoma.

PubMed

Meyer, F R L; Steinborn, R; Grausgruber, H; Wolfesberger, B; Walter, I

2015-10-01

The discovery of expression of the erythropoietin receptor (EPO-R) on neoplastic cells has led to concerns about the safety of treating anaemic cancer patients with EPO. In addition to its endocrine function, the receptor may play a role in tumour progression through an autocrine mechanism. In this study, the expression of EPO, EPO-R and platelet-derived growth factor BB (PDGF-BB) was analysed in five feline and 13 canine osteosarcomas using immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR). EPO expression was positive in all tumours by IHC, but EPO mRNA was only detected in 38% of the canine and 40% of the feline samples. EPO-R was expressed in all samples by quantitative RT-PCR (RT-qPCR) and IHC. EPO-R mRNA was expressed at higher levels in all feline tumours, tumour cell lines, and kidney when compared to canine tissues. PDGF-BB expression was variable by IHC, but mRNA was detected in all samples. To assess the functionality of the EPO-R on tumour cells, the proliferation of canine and feline osteosarcoma cell lines was evaluated after EPO administration using an alamarBlue assay and Ki67 immunostaining. All primary cell lines responded to EPO treatment in at least one of the performed assays, but the effect on proliferation was very low indicating only a weak responsiveness of EPO-R. In conclusion, since EPO and its receptor are expressed by canine and feline osteosarcomas, an autocrine or paracrine tumour progression mechanism cannot be excluded, although in vitro data suggest a minimal role of EPO-R in osteosarcoma cell proliferation. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Expression of platelet-derived growth factor BB, erythropoietin and erythropoietin receptor in canine and feline osteosarcoma

PubMed Central

Meyer, F.R.L.; Steinborn, R.; Grausgruber, H.; Wolfesberger, B.; Walter, I.

2015-01-01

The discovery of expression of the erythropoietin receptor (EPO-R) on neoplastic cells has led to concerns about the safety of treating anaemic cancer patients with EPO. In addition to its endocrine function, the receptor may play a role in tumour progression through an autocrine mechanism. In this study, the expression of EPO, EPO-R and platelet-derived growth factor BB (PDGF-BB) was analysed in five feline and 13 canine osteosarcomas using immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR). EPO expression was positive in all tumours by IHC, but EPO mRNA was only detected in 38% of the canine and 40% of the feline samples. EPO-R was expressed in all samples by quantitative RT-PCR (RT-qPCR) and IHC. EPO-R mRNA was expressed at higher levels in all feline tumours, tumour cell lines, and kidney when compared to canine tissues. PDGF-BB expression was variable by IHC, but mRNA was detected in all samples. To assess the functionality of the EPO-R on tumour cells, the proliferation of canine and feline osteosarcoma cell lines was evaluated after EPO administration using an alamarBlue assay and Ki67 immunostaining. All primary cell lines responded to EPO treatment in at least one of the performed assays, but the effect on proliferation was very low indicating only a weak responsiveness of EPO-R. In conclusion, since EPO and its receptor are expressed by canine and feline osteosarcomas, an autocrine or paracrine tumour progression mechanism cannot be excluded, although in vitro data suggest a minimal role of EPO-R in osteosarcoma cell proliferation. PMID:26189892

Real-time imaging of inflation-induced ATP release in the ex vivo rat lung.

PubMed

Furuya, Kishio; Tan, Ju Jing; Boudreault, Francis; Sokabe, Masahiro; Berthiaume, Yves; Grygorczyk, Ryszard

2016-11-01

Extracellular ATP and other nucleotides are important autocrine/paracrine mediators that regulate diverse processes critical for lung function, including mucociliary clearance, surfactant secretion, and local blood flow. Cellular ATP release is mechanosensitive; however, the impact of physical stimuli on ATP release during breathing has never been tested in intact lungs in real time and remains elusive. In this pilot study, we investigated inflation-induced ATP release in rat lungs ex vivo by real-time luciferin-luciferase (LL) bioluminescence imaging coupled with simultaneous infrared tissue imaging to identify ATP-releasing sites. With LL solution introduced into air spaces, brief inflation of such edematous lung (1 s, ∼20 cmH 2 O) induced transient (<30 s) ATP release in a limited number of air-inflated alveolar sacs during their recruitment/opening. Released ATP reached concentrations of ∼10 -6 M, relevant for autocrine/paracrine signaling, but it remained spatially restricted to single alveolar sacs or their clusters. ATP release was stimulus dependent: prolonged (100 s) inflation evoked long-lasting ATP release that terminated upon alveoli deflation/derecruitment while cyclic inflation/suction produced cyclic ATP release. With LL introduced into blood vessels, inflation induced transient ATP release in many small patchlike areas the size of alveolar sacs. Findings suggest that inflation induces ATP release in both alveoli and the surrounding blood capillary network; the functional units of ATP release presumably consist of alveolar sacs or their clusters. Our study demonstrates the feasibility of real-time ATP release imaging in ex vivo lungs and provides the first direct evidence of inflation-induced ATP release in lung air spaces and in pulmonary blood capillaries, highlighting the importance of purinergic signaling in lung function. Copyright © 2016 the American Physiological Society.

Stable Ectopic Expression of ST6GALNAC5 Induces Autocrine MET Activation and Anchorage-Independence in MDCK Cells.

PubMed

Chu, Chia; Bottaro, Donald P; Betenbaugh, Michael J; Shiloach, Joseph

2016-01-01

The epithelial-mesenchymal transition (EMT) is a complex cancer progression that can boost the metastatic potential of transformed cells by inducing migration, loss of cell adhesion, and promoting proliferation under anchorage-independent conditions. A DNA microarray analysis was performed comparing parental anchorage-dependent MDCK cells and anchorage-independent MDCK cells that were engineered to express human siat7e (ST6GALNAC5). The comparison identified several genes involved in the EMT process that were differentially expressed between the anchorage-dependent and the anchorage-independent MDCK cell lines. The hepatocyte growth factor gene (hgf) was found to be over-expressed in the engineered MDCK-siat7e cells at both transcription and protein expression levels. Phosphorylation analysis of the MET receptor tyrosine kinase confirmed the activation of an autocrine loop of the HGF/ MET signaling pathway in the MDCK-siat7e cells. When MET activities were suppressed by using the small-molecular inhibitor drug PF-02341066 (Crizotinib), the anchorage-independent MDCK-siat7e cells reverted to the cellular morphology of the parental anchorage-dependent MDCK cells. These observations indicate that the MET receptor plays a central role in the growth properties of the MDCK cells and its phosphorylation status is likely dependent on sialylation. Further investigation of the downstream signaling targets in the MET network showed that the degree of MDCK cell adhesion correlated with secretion levels of a matrix metalloproteinase, MMP1, suggesting a role of metalloproteinases in the EMT process. These results demonstrate that in addition to its application in biotechnology processes, MDCK-siat7e may serve as a model cell for metastasis studies to decipher the sequence of events leading up to the activation of EMT.

Constitutive IDO expression in human cancer is sustained by an autocrine signaling loop involving IL-6, STAT3 and the AHR

PubMed Central

Sahm, Felix; Rauschenbach, Katharina J.; Trump, Saskia; Winter, Marcus; Ott, Martina; Ochs, Katharina; Lutz, Christian; Liu, Xiangdong; Anastasov, Natasa; Lehmann, Irina; Höfer, Thomas; von Deimling, Andreas; Wick, Wolfgang; Platten, Michael

2014-01-01

Indoleamine-2,3-dioxygenase (IDO) inhibitors have entered clinical trials based on their ability to restore anti-tumor immunity in preclinical studies. However, the mechanisms leading to constitutive expression of IDO in human tumors are largely unknown. Here we analyzed the pathways mediating constitutive IDO expression in human cancer. IDO-positive tumor cells and tissues showed basal phosphorylation and acetylation of STAT3 as evidenced by western blotting and immunoprecipitation. Inhibition of IL-6 or STAT3 using siRNA and/or pharmacological inhibitors reduced IDO mRNA and protein expression as well as kynurenine formation. In turn, IDO enzymatic activity activated the AHR as shown by the induction of AHR target genes. IDO-mediated AHR activation induced IL-6 expression, while inhibition or knockdown of the AHR reduced IL-6 expression. IDO activity thus sustains its own expression via an autocrine AHR–IL-6–STAT3 signaling loop. Inhibition of the AHR–IL-6–STAT3 signaling loop restored T-cell proliferation in mixed leukocyte reactions performed in the presence of IDO-expressing human cancer cells. Identification of the IDO-AHR-IL-6-STAT3 signaling loop maintaining IDO expression in human cancers reveals novel therapeutic targets for the inhibition of this core pathway promoting immunosuppression of human cancers. The relevance of the IDO-AHR-IL-6-STAT3 transcriptional circuit is underscored by the finding that high expression of its members IDO, STAT3 and the AHR target gene CYP1B1 is associated with reduced relapse-free survival in lung cancer patients. PMID:24657910

Parthenogenic Blastocysts Derived from Cumulus-Free In Vitro Matured Human Oocytes

PubMed Central

McElroy, Sohyun L.; Byrne, James A.; Chavez, Shawn L.; Behr, Barry; Hsueh, Aaron J.; Westphal, Lynn M.; Reijo Pera, Renee A.

2010-01-01

Background Approximately 20% of oocytes are classified as immature and discarded following intracytoplasmic sperm injection (ICSI) procedures. These oocytes are obtained from gonadotropin-stimulated patients, and are routinely removed from the cumulus cells which normally would mature the oocytes. Given the ready access to these human oocytes, they represent a potential resource for both clinical and basic science application. However culture conditions for the maturation of cumulus-free oocytes have not been optimized. We aimed to improve maturation conditions for cumulus-free oocytes via culture with ovarian paracrine/autocrine factors identified by single cell analysis. Methodology/Principal Finding Immature human oocytes were matured in vitro via supplementation with ovarian paracrine/autocrine factors that were selected based on expression of ligands in the cumulus cells and their corresponding receptors in oocytes. Matured oocytes were artificially activated to assess developmental competence. Gene expression profiles of parthenotes were compared to IVF/ICSI embryos at morula and blastocyst stages. Following incubation in medium supplemented with ovarian factors (BDNF, IGF-I, estradiol, GDNF, FGF2 and leptin), a greater percentage of oocytes demonstrated nuclear maturation and subsequently, underwent parthenogenesis relative to control. Similarly, cytoplasmic maturation was also improved as indicated by development to blastocyst stage. Parthenogenic blastocysts exhibited mRNA expression profiles similar to those of blastocysts obtained after IVF/ICSI with the exception for MKLP2 and PEG1. Conclusions/Significance Human cumulus-free oocytes from hormone-stimulated cycles are capable of developing to blastocysts when cultured with ovarian factor supplementation. Our improved IVM culture conditions may be used for obtaining mature oocytes for clinical purposes and/or for derivation of embryonic stem cells following parthenogenesis or nuclear transfer. PMID:20539753

Reciprocal Cross Talk between Gonadotropin-Releasing Hormone (GnRH) and Prostaglandin Receptors Regulates GnRH Receptor Expression and Differential Gonadotropin Secretion

PubMed Central

Naor, Zvi; Jabbour, Henry N.; Naidich, Michal; Pawson, Adam J.; Morgan, Kevin; Battersby, Sharon; Millar, Michael R.; Brown, Pamela; Millar, Robert P.

2007-01-01

The asynchronous secretion of gonadotrope LH and FSH under the control of GnRH is crucial for ovarian cyclicity but the underlying mechanism is not fully resolved. Because prostaglandins (PG) are autocrine regulators in many tissues, we determined whether they have this role in gonadotropes. We first demonstrated that GnRH stimulates PG synthesis by induction of cyclooxygenase-2, via the protein kinase C/c-Src/phosphatidylinositol 3′-kinase/MAPK pathway in the LβT2 gonadotrope cell line. We then demonstrated that PGF2α and PGI2, but not PGE2 inhibited GnRH receptor expression by inhibition of phosphoinositide turnover. PGF2α, but not PGI2 or PGE2, reduced GnRH-induction of LHβ gene expression, but not the α-gonadotropin subunit or the FSHβ subunit genes. The prostanoid receptors EP1, EP2, FP, and IP were expressed in rat gonadotropes. Incubations of rat pituitaries with PGF2α, but not PGI2 or PGE2, inhibited GnRH-induced LH secretion, whereas the cyclooxygenase inhibitor, indomethacin, stimulated GnRH-induced LH secretion. None of these treatments had any effect on GnRH-induced FSH secretion. The findings have thus elaborated a novel GnRH signaling pathway mediated by PGF2α-FP and PGI2-IP, which acts through an autocrine/paracrine modality to limit autoregulation of the GnRH receptor and differentially inhibit LH and FSH release. These findings provide a mechanism for asynchronous LH and FSH secretions and suggest the use of combination therapies of GnRH and prostanoid analogs to treat infertility, diseases with unbalanced LH and FSH secretion and in hormone-dependent diseases such as prostatic cancer. PMID:17138645

GABAA receptor: a unique modulator of excitability, Ca2+ signaling, and catecholamine release of rat chromaffin cells.

PubMed

Alejandre-García, Tzitzitlini; Peña-Del Castillo, Johanna G; Hernández-Cruz, Arturo

2018-01-01

The role of gamma-aminobutyric acid (GABA) in adrenal medulla chromaffin cell (CC) function is just beginning to unfold. GABA is stored in catecholamine (CA)-containing dense core granules and is presumably released together with CA, ATP, and opioids in response to physiological stimuli, playing an autocrine-paracrine role on CCs. The reported paradoxical "dual action" of GABA A -R activation (enhancement of CA secretion and inhibition of synaptically evoked CA release) is only one aspect of GABA's multifaceted actions. In this review, we discuss recent physiological experiments on rat CCs in situ which suggest that GABA regulation of CC function may depend on the physiological context: During non-stressful conditions, GABA A -R activation by endogenous GABA tonically inhibits acetylcholine release from splanchnic nerve terminals and decreases spontaneous Ca 2+ fluctuations in CCs, preventing unwanted CA secretion. During intense stress, splanchnic nerve terminals release acetylcholine, which depolarizes CCs and allows the Ca 2+ influx that triggers the release of CA and GABA. With time, CA secretion declines, due to voltage-independent inhibition of Ca 2+ channels and desensitization of cholinergic nicotinic receptors. Nonetheless, acute activation of GABA A -R is depolarizing in about 50% of CCs, and thus GABA, acting as an autocrine/paracrine mediator, could help to maintain CA exocytosis under stress. GABA A -R activation is not excitatory in about half of CCs' population because it hyperpolarizes them or elicits no response. This percentage possibly varies, depending on functional demands, since GABA A -R-mediated actions are determined by the intracellular chloride concentration ([Cl - ] i ) and therefore on the activity of cation-chloride co transporters, which is functionally regulated. These findings underscore a potential importance of a novel and complex GABA-mediated regulation of CC function and of CA secretion.

Long pentraxin-3 as an epithelial-stromal fibroblast growth factor-targeting inhibitor in prostate cancer.

PubMed

Ronca, Roberto; Alessi, Patrizia; Coltrini, Daniela; Di Salle, Emanuela; Giacomini, Arianna; Leali, Daria; Corsini, Michela; Belleri, Mirella; Tobia, Chiara; Garlanda, Cecilia; Bonomi, Elisa; Tardanico, Regina; Vermi, William; Presta, Marco

2013-06-01

Fibroblast growth factors (FGFs) exert autocrine/paracrine functions in prostate cancer by stimulating angiogenesis and tumour growth. Here dihydrotestosterone (DHT) up-regulates FGF2 and FGF8b production in murine TRAMP-C2 prostate cancer cells, activating a FGF-dependent autocrine loop of stimulation. The soluble pattern recognition receptor long pentraxin-3 (PTX3) acts as a natural FGF antagonist that binds FGF2 and FGF8b via its N-terminal domain. We demonstrate that recombinant PTX3 protein and the PTX3-derived pentapeptide Ac-ARPCA-NH2 abolish the mitogenic response of murine TRAMP-C2 cells and human LNCaP prostate cancer cells to DHT and FGFs. Also, PTX3 hampers the angiogenic activity of DHT-activated TRAMP-C2 cells on the chick embryo chorioallantoic membrane (CAM). Accordingly, human PTX3 overexpression inhibits the mitogenic activity exerted by DHT or FGFs on hPTX3_TRAMP-C2 cell transfectants and their angiogenic activity. Also, hPTX3_TRAMP-C2 cells show a dramatic decrease of their angiogenic and tumourigenic potential when grafted in syngeneic or immunodeficient athymic male mice. A similar inhibitory effect is observed when TRAMP-C2 cells overexpress only the FGF-binding N-terminal PTX3 domain. In keeping with the anti-tumour activity of PTX3 in experimental prostate cancer, immunohistochemical analysis of prostate needle biopsies from primary prostate adenocarcinoma patients shows that parenchymal PTX3 expression, abundant in basal cells of normal glands, is lost in high-grade prostatic intraepithelial neoplasia and in invasive tumour areas. These results identify PTX3 as a potent FGF antagonist endowed with anti-angiogenic and anti-neoplastic activity in prostate cancer. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Fluid shear stress stimulates prostaglandin and nitric oxide release in bone marrow-derived preosteoclast-like cells

NASA Technical Reports Server (NTRS)

McAllister, T. N.; Du, T.; Frangos, J. A.

2000-01-01

Bone is a porous tissue that is continuously perfused by interstitial fluid. Fluid flow, driven by both vascular pressure and mechanical loading, may generate significant shear stresses through the canaliculi as well as along the bone lining at the endosteal surface. Both osteoblasts and osteocytes produce signaling factors such as prostaglandins and nitric in response to fluid shear stress (FSS); however, these humoral agents appear to have more profound affects on osteoclast activity at the endosteal surface. We hypothesized that osteoclasts and preosteoclasts may also be mechanosensitive and that osteoclast-mediated autocrine signaling may be important in bone remodeling. In this study, we investigated the effect of FSS on nitric oxide (NO), prostaglandin E(2) (PGE(2)), and prostacyclin (PGI(2)) release by neonatal rat bone marrow-derived preosteoclast-like cells. These cells were tartrate-resistant acid phosphatase (TRAP) positive, weakly nonspecific esterase (NSE) positive, and capable of fusing into calcitonin-responsive, bone-resorbing, multinucleated cells. Bone marrow-derived preosteoclast-like cells exposed for 6 h to a well-defined FSS of 16 dynes/cm(2) produced NO at a rate of 7.5 nmol/mg protein/h, which was 10-fold that of static controls. This response was completely abolished by 100 microM N(G)-amino-L-arginine (L-NAA). Flow also stimulated PGE(2) production (3.9 microg/mg protein/h) and PGI(2) production (220 pg/mg protein/h). L-NAA attenuated flow-induced PGE(2) production by 30%, suggesting that NO may partially modulate PGE(2) production. This is the first report demonstrating that marrow derived cells are sensitive to FSS and that autocrine signaling in these cells may play an important role in load-induced remodeling and signal transduction in bone. Copyright 2000 Academic Press.

Reactive Oxygen Species Alter Autocrine and Paracrine Signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zangar, Richard C.; Bollinger, Nikki; Weber, Thomas J.

2011-12-01

Cytochrome P450 (P450) 3A4 (CYP3A4) is the most abundant P450 protein in human liver and intestine and is highly inducible by a variety of drugs and other compounds. The P450 catalytic cycle is known to uncouple and release reactive oxygen species (ROS), but the effects of ROS from P450 and other enzymes in the endo-plasmic reticulum have been poorly studied from the perspective of effects on cell biology. In this study, we expressed low levels of CYP3A4 in HepG2 cells, a human hepatocarcinoma cell line, and examined effects on intracellular levels of ROS and on the secretion of a varietymore » of growth factors that are important in extracellular communication. Using the redox-sensitive dye RedoxSensor red, we demonstrate that CYP3A4 expression increases levels of ROS in viable cells. A customELISA microarray platform was employed to demonstrate that expression of CYP3A4 increased secretion of amphiregulin, intracellular adhesion molecule 1, matrix metalloprotease 2, platelet-derived growth factor (PDGF), and vascular endothelial growth factor, but suppressed secretion of CD14. The antioxidant N-acetylcysteine suppressed all P450-dependent changes in protein secretion except for CD14. Quantitative RT-PCR demonstrated that changes in protein secretion were consistently associated with corresponding changes in gene expression. Inhibition of the NF-{kappa}B pathway blocked P450 effects on PDGF secretion. CYP3A4 expression also altered protein secretion in human mammary epithelial cells and C10 mouse lung cells. Overall, these results suggest that increased ROS production in the endoplasmic reticulum alters the secretion of proteins that have key roles in paracrine and autocrine signaling.« less

Interleukin 8 mediates bcl-xL-induced enhancement of human melanoma cell dissemination and angiogenesis in a zebrafish xenograft model.

PubMed

Gabellini, Chiara; Gómez-Abenza, Elena; Ibáñez-Molero, Sofia; Tupone, Maria Grazia; Pérez-Oliva, Ana B; de Oliveira, Sofia; Del Bufalo, Donatella; Mulero, Victoriano

2018-02-01

The protein bcl-xL is able to enhance the secretion of the proinflammatory chemokine interleukin 8 (CXCL8) in human melanoma lines. In this study, we investigate whether the bcl-xL/CXCL8 axis is important for promoting melanoma angiogenesis and aggressiveness in vivo, using angiogenesis and xenotransplantation assays in zebrafish embryos. When injected into wild-type embryos, bcl-xL-overexpressing melanoma cells showed enhanced dissemination and angiogenic activity compared with control cells. Human CXCL8 protein elicited a strong proangiogenic activity in zebrafish embryos and zebrafish Cxcr2 receptor was identified as the mediator of CXCL8 proangiogenic activity using a morpholino-mediated gene knockdown. However, human CXCL8 failed to induce neutrophil recruitment in contrast to its zebrafish homolog. Interestingly, the greater aggressiveness of bcl-xL-overexpressing melanoma cells was mediated by an autocrine effect of CXCL8 on its CXCR2 receptor, as confirmed by an shRNA approach. Finally, correlation studies of gene expression and survival analyses using microarray and RNA-seq public databases of human melanoma biopsies revealed that bcl-xL expression significantly correlated with the expression of CXCL8 and other markers of melanoma progression. More importantly, a high level of co-expression of bcl-xL and CXCL8 was associated with poor prognosis in melanoma patients. In conclusion, these data demonstrate the existence of an autocrine CXCL8/CXCR2 signaling pathway in the bcl-xL-induced melanoma aggressiveness, encouraging the development of novel therapeutic approaches for high bcl-xL-expressing melanoma. © 2017 UICC.

Glucocorticoid- and Protein Kinase A–Dependent Transcriptome Regulation in Airway Smooth Muscle

PubMed Central

Misior, Anna M.; Deshpande, Deepak A.; Loza, Matthew J.; Pascual, Rodolfo M.; Hipp, Jason D.; Penn, Raymond B.

2009-01-01

Glucocorticoids (GCs) and protein kinase A (PKA)–activating agents (β-adrenergic receptor agonists) are mainstream asthma therapies based on their ability to prevent or reverse excessive airway smooth muscle (ASM) constriction. Their abilities to regulate another important feature of asthma—excessive ASM growth—are poorly understood. Recent studies have suggested that GCs render agents of inflammation such as IL-1β and TNF-α mitogenic to ASM, via suppression of (antimitogenic) induced cyclooxygenase-2–dependent PKA activity. To further explore the mechanistic basis of these observations, we assessed the effects of epidermal growth factor and IL-1β stimulation, and the modulatory effects of GC treatment and PKA inhibition, on the ASM transcriptome by microarray analysis. Results demonstrate that ASM stimulated with IL-1β, in a manner that is often cooperative with stimulation with epidermal growth factor, exhibit a profound capacity to function as immunomodulatory cells. Moreover, results implicate an important role for induced autocrine/paracrine factors (many whose regulation was minimally affected by GCs or PKA inhibition) as regulators of both airway inflammation and ASM growth. Induction of numerous chemokines, in conjunction with regulation of proteases and agents of extracellular matrix remodeling, is suggested as an important mechanism promoting upregulated G protein–coupled receptor signaling capable of stimulating ASM growth. Additional functional assays suggest that intracellular PKA plays a critical role in suppressing the promitogenic effects of induced autocrine factors in ASM. Finally, identification and comparison of GC- and PKA-sensitive genes in ASM provide insight into the complementary effects of β-agonist/GC combination therapies, and suggest specific genes as important targets for guiding the development of new generations of GCs and adjunct asthma therapies. PMID:19059887

EGFR Ligands Drive Multipotential Stromal Cells to Produce Multiple Growth Factors and Cytokines via Early Growth Response-1

PubMed Central

Kerpedjieva, Svetoslava S.; Kim, Duk Soo; Barbeau, Dominique J.

2012-01-01

Cell therapy with adult bone marrow multipotential stromal cells/mesenchymal stem cells (MSCs) presents a promising approach to promote wound healing and tissue regeneration. The strong paracrine capability of various growth factors and cytokines is a key mechanism of MSC-mediated wound healing and tissue regeneration, and the goal of this study is to understand the underlying mechanism that supports the strong paracrine machineries in MSCs. Microarray database analyses revealed that early growth response-1 (EGR1) is highly expressed in MSCs. Our previous studies showed that epidermal growth factor (EGF) treatment induces growth factor production in MSCs in vitro. Since EGF strongly upregulates EGR1, we hypothesized that EGF receptor (EGFR)–EGR1 signaling plays a pivotal role in MSC paracrine activity. EGF treatment upregulated the gene expression of growth factors and cytokines, including EGFR ligands in a protein kinase C (PKC)- and/or mitogen-activated protein kinase–extracellular-signal-regulated kinase-dependent manner, and it was reversed by shRNA against EGR1. PKC activator phorbol 12-myristate 13-acetate enhanced EGFR tyrosyl phosphorylation and upregulated the gene expression of growth factors and cytokines in a heparin-binding EGF-like growth factor (HBEGF) inhibitor CRM197 sensitive manner, indicating an involvement of autocrined HBEGF in the downstream of PKC signaling. Moreover, stimulation with growth factors and cytokines induced the expression of EGFR ligands, presumably via EGR1 upregulation. These data indicate EGR1 as a convergence point of multiple signaling pathways, which in turn augments the production of multiple growth factors and cytokines by enhancing the autocrine signaling with EGFR ligands. PMID:22316125

Function-specific intracellular signaling pathways downstream of heparin-binding EGF-like growth factor utilized by human trophoblasts.

PubMed

Jessmon, Philip; Kilburn, Brian A; Romero, Roberto; Leach, Richard E; Armant, D Randall

2010-05-01

Heparin-binding EGF-like growth factor (HBEGF) is expressed by trophoblast cells throughout gestation. First-trimester cytotrophoblast cells are protected from hypoxia-induced apoptosis because of the accumulation of HBEGF through a posttranscriptional autocrine mechanism. Exogenous application of HBEGF is cytoprotective in a hypoxia/reoxygenation (H/R) injury model and initiates trophoblast extravillous differentiation to an invasive phenotype. The downstream signaling pathways induced by HBEGF that mediate these various cellular activities were identified using two human first-trimester cytotrophoblast cell lines, HTR-8/SVneo and SW.71, with similar results. Recombinant HBEGF (1 nM) induced transient phosphorylation of MAPK3/1 (ERK), MAPK14 (p38), and AKT within 15 min and JNK after 1-2 h. To determine which downstream pathways regulate the various functions of HBEGF, cells were treated with specific inhibitors of the ERK upstream regulator MEK (U0126), the AKT upstream regulator phosphoinositide-3 (PI3)-kinase (LY294002), MAPK14 (SB203580), and JNK (SP600125), as well as with inactive structural analogues. Only SB203580 specifically prevented HBEGF-mediated rescue during H/R, while each inhibitor attenuated HBEGF-stimulated cell migration. Accumulation of HBEGF at reduced oxygen was blocked only by a combination of U0126, SB203580, and SP600125. We conclude that HBEGF advances trophoblast extravillous differentiation through coordinate activation of PI3 kinase, ERK, MAPK14, and JNK, while only MAPK14 is required for its antiapoptotic activity. Additionally, hypoxia induces an autocrine increase in HBEGF protein levels through MAPK14, JNK or ERK. These experiments reveal a complexity of the intracellular signaling circuitry that regulates trophoblast functions critical for implantation and placentation.

EGFR ligands drive multipotential stromal cells to produce multiple growth factors and cytokines via early growth response-1.

PubMed

Kerpedjieva, Svetoslava S; Kim, Duk Soo; Barbeau, Dominique J; Tamama, Kenichi

2012-09-01

Cell therapy with adult bone marrow multipotential stromal cells/mesenchymal stem cells (MSCs) presents a promising approach to promote wound healing and tissue regeneration. The strong paracrine capability of various growth factors and cytokines is a key mechanism of MSC-mediated wound healing and tissue regeneration, and the goal of this study is to understand the underlying mechanism that supports the strong paracrine machineries in MSCs. Microarray database analyses revealed that early growth response-1 (EGR1) is highly expressed in MSCs. Our previous studies showed that epidermal growth factor (EGF) treatment induces growth factor production in MSCs in vitro. Since EGF strongly upregulates EGR1, we hypothesized that EGF receptor (EGFR)-EGR1 signaling plays a pivotal role in MSC paracrine activity. EGF treatment upregulated the gene expression of growth factors and cytokines, including EGFR ligands in a protein kinase C (PKC)- and/or mitogen-activated protein kinase-extracellular-signal-regulated kinase-dependent manner, and it was reversed by shRNA against EGR1. PKC activator phorbol 12-myristate 13-acetate enhanced EGFR tyrosyl phosphorylation and upregulated the gene expression of growth factors and cytokines in a heparin-binding EGF-like growth factor (HBEGF) inhibitor CRM197 sensitive manner, indicating an involvement of autocrined HBEGF in the downstream of PKC signaling. Moreover, stimulation with growth factors and cytokines induced the expression of EGFR ligands, presumably via EGR1 upregulation. These data indicate EGR1 as a convergence point of multiple signaling pathways, which in turn augments the production of multiple growth factors and cytokines by enhancing the autocrine signaling with EGFR ligands.

Function-Specific Intracellular Signaling Pathways Downstream of Heparin-Binding EGF-Like Growth Factor Utilized by Human Trophoblasts1

PubMed Central

Jessmon, Philip; Kilburn, Brian A.; Romero, Roberto; Leach, Richard E.; Armant, D. Randall

2010-01-01

Heparin-binding EGF-like growth factor (HBEGF) is expressed by trophoblast cells throughout gestation. First-trimester cytotrophoblast cells are protected from hypoxia-induced apoptosis because of the accumulation of HBEGF through a posttranscriptional autocrine mechanism. Exogenous application of HBEGF is cytoprotective in a hypoxia/reoxygenation (H/R) injury model and initiates trophoblast extravillous differentiation to an invasive phenotype. The downstream signaling pathways induced by HBEGF that mediate these various cellular activities were identified using two human first-trimester cytotrophoblast cell lines, HTR-8/SVneo and SW.71, with similar results. Recombinant HBEGF (1 nM) induced transient phosphorylation of MAPK3/1 (ERK), MAPK14 (p38), and AKT within 15 min and JNK after 1–2 h. To determine which downstream pathways regulate the various functions of HBEGF, cells were treated with specific inhibitors of the ERK upstream regulator MEK (U0126), the AKT upstream regulator phosphoinositide-3 (PI3)-kinase (LY294002), MAPK14 (SB203580), and JNK (SP600125), as well as with inactive structural analogues. Only SB203580 specifically prevented HBEGF-mediated rescue during H/R, while each inhibitor attenuated HBEGF-stimulated cell migration. Accumulation of HBEGF at reduced oxygen was blocked only by a combination of U0126, SB203580, and SP600125. We conclude that HBEGF advances trophoblast extravillous differentiation through coordinate activation of PI3 kinase, ERK, MAPK14, and JNK, while only MAPK14 is required for its antiapoptotic activity. Additionally, hypoxia induces an autocrine increase in HBEGF protein levels through MAPK14, JNK or ERK. These experiments reveal a complexity of the intracellular signaling circuitry that regulates trophoblast functions critical for implantation and placentation. PMID:20130271

Electrical stimulation induces IL-6 in skeletal muscle through extracellular ATP by activating Ca(2+) signals and an IL-6 autocrine loop.

PubMed

Bustamante, Mario; Fernández-Verdejo, Rodrigo; Jaimovich, Enrique; Buvinic, Sonja

2014-04-15

Interleukin-6 (IL-6) is an important myokine that is highly expressed in skeletal muscle cells upon exercise. We assessed IL-6 expression in response to electrical stimulation (ES) or extracellular ATP as a known mediator of the excitation-transcription mechanism in skeletal muscle. We examined whether the canonical signaling cascade downstream of IL-6 (IL-6/JAK2/STAT3) also responds to muscle cell excitation, concluding that IL-6 influences its own expression through a positive loop. Either ES or exogenous ATP (100 μM) increased both IL-6 expression and p-STAT3 levels in rat myotubes, a process inhibited by 100 μM suramin and 2 U/ml apyrase. ATP also evoked IL-6 expression in both isolated skeletal fibers and extracts derived from whole FDB muscles. ATP increased IL-6 release up to 10-fold. STAT3 activation evoked by ATP was abolished by the JAK2 inhibitor HBC. Blockade of secreted IL-6 with a neutralizing antibody or preincubation with the STAT3 inhibitor VIII reduced STAT3 activation evoked by extracellular ATP by 70%. Inhibitor VIII also reduced by 70% IL-6 expression evoked by ATP, suggesting a positive IL-6 loop. In addition, ATP increased up to 60% the protein levels of SOCS3, a negative regulator of the IL-6 signaling pathway. On the other hand, intracellular calcium chelation or blockade of IP3-dependent calcium signals abolished STAT3 phosphorylation evoked by either extracellular ATP or ES. These results suggest that expression of IL-6 in stimulated skeletal muscle cells is mediated by extracellular ATP and nucleotide receptors, involving IP3-dependent calcium signals as an early step that triggers a positive IL-6 autocrine loop.

ATP is released by monocytes stimulated with pathogen-sensing receptor ligands and induces IL-1beta and IL-18 secretion in an autocrine way.

PubMed

Piccini, Alessandra; Carta, Sonia; Tassi, Sara; Lasiglié, Denise; Fossati, Gianluca; Rubartelli, Anna

2008-06-10

IL-1beta and IL-18 are crucial mediators of inflammation, and a defective control of their release may cause serious diseases. Yet, the mechanisms regulating IL-1beta and IL-18 secretion are partially undefined. Both cytokines are produced as inactive cytoplasmic precursors. Processing to the active form is mediated by caspase-1, which is in turn activated by the multiprotein complex inflammasome. Here, we show that in primary human monocytes microbial components acting on different pathogen-sensing receptors and the danger-associated molecule uric acid are all competent to induce maturation and secretion of IL-1beta and IL-18 through a process that involves as a first event the extracellular release of endogenous ATP. ATP release is followed by autocrine stimulation of the purinergic receptors P2X(7). Indeed, antagonists of the P2X(7) receptor (P2X(7)R), or treatment with apyrase, prevent IL-1beta and IL-18 maturation and secretion triggered by the different stimuli. At variance, blocking P2X(7)R activity has no effects on IL-1beta secretion by monocytes carrying a mutated inflammasome that does not require exogenous ATP for activation. P2X(7)R engagement is followed by K+ efflux and activation of phospholipase A(2). Both events are required for processing and secretion induced by all of the stimuli. Thus, stimuli acting on different pathogen-sensing receptors converge on a common pathway where ATP externalization is the first step in the cascade of events leading to inflammasome activation and IL-1beta and IL-18 secretion.

Expression and Function of Anti-Inflammatory Interleukins: The Other Side of the Vascular Response to Injury

PubMed Central

Cuneo, Anthony A.; Autieri, Michael V.

2012-01-01

Common to multiple vascular diseases, including atherosclerosis, interventional restenosis, and transplant vasculopathy, is a localized inflammatory reaction. Activated vascular smooth muscle cells (VSMC) respond to local inflammation and migrate from the media into the lumen of the vessel where they proliferate and synthesize cytokines which they respond to in an autocrine fashion, sustaining the progression of the lesion. The deleterious effects of pro-inflammatory cytokines, particularly immunomodulatory interleukins, on vascular pathophysiology and development of these maladaptive processes have been the subject of intense study. Although a great deal of attention has been given to the negative effects of pro-inflammatory cytokines and interleukins, relatively little has been reported on the potentially beneficial paracrine and autocrine effects of anti-inflammatory interleukins on the vascular response to injury. The vast majority of emphasis on secretion and function of anti-inflammatory mediators has been placed on leukocytes. Consequently, the role of non-immune cells, and direct effects of anti-inflammatory interleukins on vascular cells is poorly understood. We will review the molecular mechanisms whereby anti-inflammatory interleukins inhibit signal transduction and gene expression in inflammatory cells. We will review studies in which beneficial “indirect” effects of anti-inflammatory interleukins on progression of vascular disease are achieved by modulation of immune function. We will also present the limited studies in which “direct” effects of these interleukins on VSMC and endothelial cells dampen the vascular response to injury. We propose that expression of immunomodulatory cytokines by activated vasculature may represent an auto-regulatory feed back mechanism to promote resolution of the vascular response to injury. PMID:19601851

High Heregulin Expression Is Associated with Activated HER3 and May Define an Actionable Biomarker in Patients with Squamous Cell Carcinomas of the Head and Neck

PubMed Central

Shames, David S.; Carbon, Juliet; Walter, Kim; Jubb, Adrian M.; Kozlowski, Cleopatra; Januario, Tom; An, Do; Fu, Ling; Xiao, Yuanyuan; Raja, Rajiv; Jiang, Brittany; Malekafzali, Ashi; Stern, Howard; Settleman, Jeff; Wilson, Timothy R.; Hampton, Garret M.; Yauch, Robert L.; Pirzkall, Andrea; Amler, Lukas C.

2013-01-01

Purpose Tumors with oncogenic dependencies on the HER family of receptor tyrosine kinases (RTKs) often respond well to targeted inhibition. Our previous work suggested that many cell lines derived from squamous cell carcinomas of the head and neck (SCCHNs) depend on autocrine signaling driven by HER2/3 dimerization and high-level co-expression of HRG. Additionally, results from a Phase I trial of MEHD7495A, a dual-action antibody that blocks ligand binding to EGFR and HER3, suggest that high-level HRG expression was associated with clinical response in SCCHN patients. Here we explore the hypothesis that high-level HRG expression defines a subpopulation of SCCHNs with activated HER3. Experimental Design qRT-PCR expression profiling was performed on >750 tumors of diverse origin, including >150 therapy-naïve, primary, and recurrent SCCHNs. Activated HER3, defined by immunoprecipitation of phospho-HER3, was compared to HRG expression in SCCHN samples. Paracrine versus autocrine expression was evaluated using RNA-in situ hybridization. Results SCCHN tumors express the highest levels of HRG compared to a diverse collection of other tumor types. We show that high HRG expression is associated with activated HER3, whereas low HRG expression is associated with low HER3 activation in SCCHN tumors. Furthermore, HRG expression is higher in recurrent SCCHN compared to patient-matched therapy naïve specimens. Conclusions HRG expression levels define a biologically distinct subset of SCCHN patients. We propose that high-level expression of HRG is associated with constitutive activation of HER3 in SCCHN and thus defines an actionable biomarker for interventions targeting HER3. PMID:23468880

Autocrine CSF-1R signaling drives mesothelioma chemoresistance via AKT activation

PubMed Central

Cioce, M; Canino, C; Goparaju, C; Yang, H; Carbone, M; Pass, H I

2014-01-01

Clinical management of malignant pleural mesothelioma (MPM) is very challenging because of the uncommon resistance of this tumor to chemotherapy. We report here increased expression of macrophage colony-stimulating-factor-1-receptor (M-CSF/CSF-1R) mRNA in mesothelioma versus normal tissue specimens and demonstrate that CSF-1R expression identifies chemoresistant cells of mesothelial nature in both primary cultures and mesothelioma cell lines. By using RNAi or ligand trapping, we demonstrate that the chemoresistance properties of those cells depend on autocrine CSF-1R signaling. At the single-cell level, the isolated CSF-1Rpos cells exhibit a complex repertoire of pluripotency, epithelial–mesenchymal transition and detoxifying factors, which define a clonogenic, chemoresistant, precursor-like cell sub-population. The simple activation of CSF-1R in untransformed mesothelial cells is sufficient to confer clonogenicity and resistance to pemetrexed, hallmarks of mesothelioma. In addition, this induced a gene expression profile highly mimicking that observed in the MPM cells endogenously expressing the receptor and the ligands, suggesting that CSF-1R expression is mainly responsible for the phenotype of the identified cell sub-populations. The survival of CSF1Rpos cells requires active AKT (v-akt murine thymoma viral oncogene homolog 1) signaling, which contributed to increased levels of nuclear, transcriptionally competent β-catenin. Inhibition of AKT reduced the transcriptional activity of β-catenin-dependent reporters and sensitized the cells to senescence-induced clonogenic death after pemetrexed treatment. This work expands what is known on the non-macrophage functions of CSF-1R and its role in solid tumors, and suggests that CSF-1R signaling may have a critical pathogenic role in a prototypical, inflammation-related cancer such as MPM and therefore may represent a promising target for therapeutic intervention. PMID:24722292

Temporal Profiling and Pulsed SILAC Labeling Identify Novel Secreted Proteins During Ex Vivo Osteoblast Differentiation of Human Stromal Stem Cells*

PubMed Central

Kristensen, Lars P.; Chen, Li; Nielsen, Maria Overbeck; Qanie, Diyako W.; Kratchmarova, Irina; Kassem, Moustapha; Andersen, Jens S.

2012-01-01

It is well established that bone forming cells (osteoblasts) secrete proteins with autocrine, paracrine, and endocrine function. However, the identity and functional role for the majority of these secreted and differentially expressed proteins during the osteoblast (OB) differentiation process, is not fully established. To address these questions, we quantified the temporal dynamics of the human stromal (mesenchymal, skeletal) stem cell (hMSC) secretome during ex vivo OB differentiation using stable isotope labeling by amino acids in cell culture (SILAC). In addition, we employed pulsed SILAC labeling to distinguish genuine secreted proteins from intracellular contaminants. We identified 466 potentially secreted proteins that were quantified at 5 time-points during 14-days ex vivo OB differentiation including 41 proteins known to be involved in OB functions. Among these, 315 proteins exhibited more than 2-fold up or down-regulation. The pulsed SILAC method revealed a strong correlation between the fraction of isotope labeling and the subset of proteins known to be secreted and involved in OB differentiation. We verified SILAC data using qRT-PCR analysis of 9 identified potential novel regulators of OB differentiation. Furthermore, we studied the biological effects of one of these proteins, the hormone stanniocalcin 2 (STC2) and demonstrated its autocrine effects in enhancing osteoblastic differentiation of hMSC. In conclusion, combining complete and pulsed SILAC labeling facilitated the identification of novel factors produced by hMSC with potential role in OB differentiation. Our study demonstrates that the secretome of osteoblastic cells is more complex than previously reported and supports the emerging evidence that osteoblastic cells secrete proteins with endocrine functions and regulate cellular processes beyond bone formation. PMID:22801418

Berberine ameliorates collagen-induced arthritis in rats by suppressing Th17 cell responses via inducing cortistatin in the gut.

PubMed

Yue, Mengfan; Xia, Yufeng; Shi, Can; Guan, Chunge; Li, Yunfan; Liu, Rui; Wei, Zhifeng; Dai, Yue

2017-09-01

Berberine, an isoquinoline alkaloid, has been reported to ameliorate various autoimmune diseases including rheumatoid arthritis by oral administration. However, its mechanism remains mysterious due to an extremely low bioavailability. The fact that berberine readily accumulates in the gut, the largest endocrine organ in the body, attracted us to explore its anti-arthritic mechanism in view of the induction of intestinal immunosuppressive neuropeptides. In this study, berberine (200 mg·kg -1 , i.g.) was shown to ameliorate collagen-induced arthritis in rats, which was manifested by the reduction of clinical signs and joint destruction, as well as marked down-regulation of Th17 cell frequency and interleukin-17 level in blood. In contrast, an intravenous injection of berberine failed to affect arthritis in rats, implying that its anti-arthritic effect was gut-dependent. Further studies revealed that oral berberine selectively elevated the levels of cortistatin, of five gut-derived neuropeptides tested, in the intestines and sera of arthrititic rats. Antagonists of ghrelin/growth hormone secretagogue receptor 1 (a subtype of cortistatin receptor) almost completely abolished the ameliorative effect of berberine on arthritis and Th17 cell responses in rats. In vitro, berberine showed a moderate ability to promote the expression of cortistatin in nerve cells, which was strengthened when the nerve cells were cocultured with enteroendocrine cells to induce an autocrine/paracrine environment. In summary, oral berberine exerted anti-arthritic effect through inhibiting the Th17 cell response, which was closely associated with the induction of cortistatin generation from gut through augmenting autocrine/paracrine action between enteric nerve cells and endocrine cells. © 2017 Federation of European Biochemical Societies.

Substance P immunoreactivity exhibits frequent colocalization with kisspeptin and neurokinin B in the human infundibular region.

PubMed

Hrabovszky, Erik; Borsay, Beáta Á; Rácz, Kálmán; Herczeg, László; Ciofi, Philippe; Bloom, Stephen R; Ghatei, Mohammad A; Dhillo, Waljit S; Liposits, Zsolt

2013-01-01

Neurons synthesizing neurokinin B (NKB) and kisspeptin (KP) in the hypothalamic arcuate nucleus represent important upstream regulators of pulsatile gonadotropin-releasing hormone (GnRH) neurosecretion. In search of neuropeptides co-expressed in analogous neurons of the human infundibular nucleus (Inf), we have carried out immunohistochemical studies of the tachykinin peptide Substance P (SP) in autopsy samples from men (21-78 years) and postmenopausal (53-83 years) women. Significantly higher numbers of SP-immunoreactive (IR) neurons and darker labeling were observed in the Inf of postmenopausal women than in age-matched men. Triple-immunofluorescent studies localized SP immunoreactivity to considerable subsets of KP-IR and NKB-IR axons and perikarya in the infundibular region. In postmenopausal women, 25.1% of NKB-IR and 30.6% of KP-IR perikarya contained SP and 16.5% of all immunolabeled cell bodies were triple-labeled. Triple-, double- and single-labeled SP-IR axons innervated densely the portal capillaries of the infundibular stalk. In quadruple-labeled sections, these axons formed occasional contacts with GnRH-IR axons. Presence of SP in NKB and KP neurons increases the functional complexity of the putative pulse generator network. First, it is possible that SP modulates the effects of KP and NKB in axo-somatic and axo-dendritic afferents to GnRH neurons. Intrinsic SP may also affect the activity and/or neuropeptide release of NKB and KP neurons via autocrine/paracrine actions. In the infundibular stalk, SP may influence the KP and NKB secretory output via additional autocrine/paracrine mechanisms or regulate GnRH neurosecretion directly. Finally, possible co-release of SP with KP and NKB into the portal circulation could underlie further actions on adenohypophysial gonadotrophs.

PPARα autocrine regulation of Ca²⁺-regulated exocytosis in guinea pig antral mucous cells: NO and cGMP accumulation.

PubMed

Tanaka, Saori; Sugiyama, Nanae; Takahashi, Yuko; Mantoku, Daiki; Sawabe, Yukinori; Kuwabara, Hiroko; Nakano, Takashi; Shimamoto, Chikao; Matsumura, Hitoshi; Marunaka, Yoshinori; Nakahari, Takashi

2014-12-15

In antral mucous cells, acetylcholine (ACh, 1 μM) activates Ca(2+)-regulated exocytosis, consisting of a peak in exocytotic events that declines rapidly (initial phase) followed by a second slower decline (late phase) lasting during ACh stimulation. GW7647 [a peroxisome proliferation activation receptor α (PPARα) agonist] enhanced the ACh-stimulated initial phase, and GW6471 (a PPARα antagonist) abolished the GW7647-induced enhancement. However, GW6471 produced the delayed, but transient, increase in the ACh-stimulated late phase, and it also decreased the initial phase and produced the delayed increase in the late phase during stimulation with ACh alone. A similar delayed increase in the ACh-stimulated late phase is induced by an inhibitor of the PKG, Rp8BrPETcGMPS, suggesting that GW6471 inhibits cGMP accumulation. An inhibitor of nitric oxide synthase 1 (NOS1), N(5)-[imino(propylamino)methyl]-L-ornithine hydrochloride (N-PLA), also abolished the GW7647-induced-enhancement of ACh-stimulated initial phase but produced the delayed increase in the late phase. However, in the presence of N-PLA, an NO donor or 8BrcGMP enhanced the ACh-stimulated initial phase and abolished the delayed increase in the late phase. Moreover, GW7647 and ACh stimulated NO production and cGMP accumulation in antral mucosae, which was inhibited by GW6471 or N-PLA. Western blotting and immunohistochemistry revealed that NOS1 and PPARα colocalize in antral mucous cells. In conclusion, during ACh stimulation, a PPARα autocrine mechanism, which accumulates NO via NOS1 leading to cGMP accumulation, modulates the Ca(2+)-regulated exocytosis in antral mucous cells. Copyright © 2014 the American Physiological Society.

Biotin increases glucokinase expression via soluble guanylate cyclase/protein kinase G, adenosine triphosphate production and autocrine action of insulin in pancreatic rat islets.

PubMed

Vilches-Flores, Alonso; Tovar, Armando R; Marin-Hernandez, Alvaro; Rojas-Ochoa, Alberto; Fernandez-Mejia, Cristina

2010-07-01

Besides its role as a carboxylase prosthetic group, biotin has important effects on gene expression. However, the molecular mechanisms through which biotin exerts these effects are largely unknown. We previously found that biotin increases pancreatic glucokinase expression. We have now explored the mechanisms underlying this effect. Pancreatic islets from Wistar rats were treated with biotin, in the presence or absence of different types of inhibitors. Glucokinase mRNA and 18s rRNA abundance were determined by real-time PCR. Adenosine triphosphate (ATP) content was analyzed by fluorometry. Biotin treatment increased glucokinase mRNA abundance approximately one fold after 2 h; the effect was sustained up to 24 h. Inhibition of soluble guanylate cyclase or protein kinase G (PKG) signalling suppressed biotin-induced glucokinase expression. The cascade of events downstream of PKG in biotin-mediated gene transcription is not known. We found that inhibition of insulin secretion with diazoxide or nifedipine prevented biotin-stimulated glucokinase mRNA increase. Biotin treatment increased islet ATP content (control: 4.68+/-0.28; biotin treated: 6.62+/-0.26 pmol/islet) at 30 min. Inhibition of PKG activity suppressed the effects of biotin on ATP content. Insulin antibodies or inhibitors of phosphoinositol-3-kinase/Akt insulin signalling pathway prevented biotin-induced glucokinase expression. The nucleotide 8-Br-cGMP mimicked the biotin effects. We propose that the induction of pancreatic glucokinase mRNA by biotin involves guanylate cyclase and PKG activation, which leads to an increase in ATP content. This induces insulin secretion via ATP-sensitive potassium channels. Autocrine insulin, in turn, activates phosphoinositol-3-kinase/Akt signalling. Our results offer new insights into the pathways that participate in biotin-mediated gene expression. (c) 2010 Elsevier Inc. All rights reserved.

Pivotal role of PGE2 and IL-10 in the cross-regulation of dendritic cell-derived inflammatory mediators.

PubMed

Harizi, Hedi; Gualde, Norbert

2006-08-01

Exposure to pathogens induces antigen-presenting cells (APC) such as macrophages and dendritic cells (DC) to produce various endogenous mediators, including arachidonic acid (AA)-derived eicosanoids, cytokines, and nitric oxide (NO). Many secreted products of activated APC can act by themselves in an autocrine manner and modulate their function. Moreover, the cross-interaction between endogenous bioactive molecules regulates the function of professional APC with important consequences for their ability to activate and sustain immune and inflammatory responses, and to regulate immune homeostasis. Although neglected for many years when compared to their role in cardiovascular homeostasis, cancer and inflammation, the importance of eicosanoids in immunology is becoming more defined. The role of prostaglandin (PG) E2 (PGE2), one of the best known and most well studied eicosanoids, is of particular interest. It modulates the activities of professional DC by acting on their differentiation, maturation and their ability to secrete cytokines. Uniquely among haematopoietic cytokines, interleukin-10 (IL-10) is a pleiotropic molecule that displays both immunostimulatory and immunoregulatory activities. IL-10 has attached much attention because of its anti-inflammatory properties. It modulates expression of cytokines, soluble mediators and cell surface molecules by cells of myeloid origin, particularly macrophages and DC. We previously reported that PGE2 is a potent inducer of IL-10 in bone marrow-derived DC (BM-DC), and PGE2-induced IL-10 is a key regulator of the BM-DC pro-inflammatory phenotype. BM-DC may be considered as an important model to study complex interactions between endogenous mediators, and autocrine IL-10 plays a pivotal role in the crossregulation of AA-derived lipid mediators, cytokines, and NO, with critical effects on immune and inflammatory responses.

NDRG2 correlated with favorable recurrence-free survival inhibits metastasis of mouse breast cancer cells via attenuation of active TGF-β production.

PubMed

Oh, Sang-seok; Kim, Donghyeok; Kim, Dong-Hee; Chang, Hong Hee; Sohn, Kyung-Cheol; Kim, Kyo Hyun; Jung, Sung Hoo; Lee, Byoung Kil; Kim, Joo Heon; Kim, Kwang Dong

2012-10-01

N-myc downstream-regulated gene 2 (NDRG2) has been studied for its inhibitory effects against growth and metastasis of many tumor cell types. In this study, we showed NDRG2 expression was correlated with favorable recurrence-free survival of patients with breast cancer and inhibited metastasis of breast cancer cells (4T1). NDRG2 expression was examined in 189 breast carcinoma tissues and paired normal breast tissues using immunohistochemistry. Histological and clinicopathological data were correlated using Pearson's chi-square test of independence. NDRG2 expression in human breast cancer tissues was inversely associated with lymph node metastasis and pTNM stage. Furthermore, patients with breast cancer with a high level of NDRG2 expression showed favorable recurrence-free survival (P = 0.038). To study the effect of NDRG2 on metastasis in vivo, we established an NDRG2-overexpressing mouse breast cancer cell line (4T1-NDRG2) and measured the metastasis and survival of 4T1-NDRG2 tumor-bearing mice. To test whether transforming growth factor β (TGF-β)- mediated metastasis of 4T1 was inhibited by NDRG2 expression, TGF-Smad-binding element (SBE)-luciferase activity and/or measurement of active TGF-β were performed in cell or tumor tissue level. 4T1-NDRG2 cells grew gradually and showed less metastatic activity in vivo and low invasiveness in vitro. 4T1-NDRG2 cells showed lower SBE-luciferase activity and lower level of active autocrine TGF-β than 4T1-Mock did. Correctly, our data show that NDRG2 significantly suppress tumor metastasis by attenuating active autocrine TGF-β production, and the attenuation might be typically associated with the favorable recurrence-free survival of patients clinically.

Direct Melanoma Cell Contact Induces Stromal Cell Autocrine Prostaglandin E2-EP4 Receptor Signaling That Drives Tumor Growth, Angiogenesis, and Metastasis.

PubMed

Inada, Masaki; Takita, Morichika; Yokoyama, Satoshi; Watanabe, Kenta; Tominari, Tsukasa; Matsumoto, Chiho; Hirata, Michiko; Maru, Yoshiro; Maruyama, Takayuki; Sugimoto, Yukihiko; Narumiya, Shuh; Uematsu, Satoshi; Akira, Shizuo; Murphy, Gillian; Nagase, Hideaki; Miyaura, Chisato

2015-12-11

The stromal cells associated with tumors such as melanoma are significant determinants of tumor growth and metastasis. Using membrane-bound prostaglandin E synthase 1 (mPges1(-/-)) mice, we show that prostaglandin E2 (PGE2) production by host tissues is critical for B16 melanoma growth, angiogenesis, and metastasis to both bone and soft tissues. Concomitant studies in vitro showed that PGE2 production by fibroblasts is regulated by direct interaction with B16 cells. Autocrine activity of PGE2 further regulates the production of angiogenic factors by fibroblasts, which are key to the vascularization of both primary and metastatic tumor growth. Similarly, cell-cell interactions between B16 cells and host osteoblasts modulate mPGES-1 activity and PGE2 production by the osteoblasts. PGE2, in turn, acts to stimulate receptor activator of NF-κB ligand expression, leading to osteoclast differentiation and bone erosion. Using eicosanoid receptor antagonists, we show that PGE2 acts on osteoblasts and fibroblasts in the tumor microenvironment through the EP4 receptor. Metastatic tumor growth and vascularization in soft tissues was abrogated by an EP4 receptor antagonist. EP4-null Ptger4(-/-) mice do not support B16 melanoma growth. In vitro, an EP4 receptor antagonist modulated PGE2 effects on fibroblast production of angiogenic factors. Our data show that B16 melanoma cells directly influence host stromal cells to generate PGE2 signals governing neoangiogenesis and metastatic growth in bone via osteoclast erosive activity as well as angiogenesis in soft tissue tumors. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Direct Melanoma Cell Contact Induces Stromal Cell Autocrine Prostaglandin E2-EP4 Receptor Signaling That Drives Tumor Growth, Angiogenesis, and Metastasis*

PubMed Central

Inada, Masaki; Takita, Morichika; Yokoyama, Satoshi; Watanabe, Kenta; Tominari, Tsukasa; Matsumoto, Chiho; Hirata, Michiko; Maru, Yoshiro; Maruyama, Takayuki; Sugimoto, Yukihiko; Narumiya, Shuh; Uematsu, Satoshi; Akira, Shizuo; Murphy, Gillian; Nagase, Hideaki; Miyaura, Chisato

2015-01-01

The stromal cells associated with tumors such as melanoma are significant determinants of tumor growth and metastasis. Using membrane-bound prostaglandin E synthase 1 (mPges1−/−) mice, we show that prostaglandin E2 (PGE2) production by host tissues is critical for B16 melanoma growth, angiogenesis, and metastasis to both bone and soft tissues. Concomitant studies in vitro showed that PGE2 production by fibroblasts is regulated by direct interaction with B16 cells. Autocrine activity of PGE2 further regulates the production of angiogenic factors by fibroblasts, which are key to the vascularization of both primary and metastatic tumor growth. Similarly, cell-cell interactions between B16 cells and host osteoblasts modulate mPGES-1 activity and PGE2 production by the osteoblasts. PGE2, in turn, acts to stimulate receptor activator of NF-κB ligand expression, leading to osteoclast differentiation and bone erosion. Using eicosanoid receptor antagonists, we show that PGE2 acts on osteoblasts and fibroblasts in the tumor microenvironment through the EP4 receptor. Metastatic tumor growth and vascularization in soft tissues was abrogated by an EP4 receptor antagonist. EP4-null Ptger4−/− mice do not support B16 melanoma growth. In vitro, an EP4 receptor antagonist modulated PGE2 effects on fibroblast production of angiogenic factors. Our data show that B16 melanoma cells directly influence host stromal cells to generate PGE2 signals governing neoangiogenesis and metastatic growth in bone via osteoclast erosive activity as well as angiogenesis in soft tissue tumors. PMID:26475855

Fibroblast Growth Factor Receptors Are Components of Autocrine Signaling Networks in Head and Neck Squamous Cell Carcinoma Cells

PubMed Central

Marshall, Marianne E.; Hinz, Trista K.; Kono, Scott A.; Singleton, Katherine R.; Bichon, Brady; Ware, Kathryn E.; Marek, Lindsay; Frederick, Barbara A.; Raben, David; Heasley, Lynn E.

2011-01-01

Purpose We previously reported that a fibroblast growth factor (FGF) receptor (FGFR) signaling pathway drives growth of lung cancer cell lines of squamous and large cell histologies. Herein, we explored FGFR dependency in cell lines derived from the tobacco-related malignancy, head and neck squamous cell carcinoma (HNSCC). Experimental Design FGF and FGFR mRNA and protein expression was assessed in nine HNSCC cell lines. Dependence on secreted FGF2 for cell growth was tested with FP-1039, an FGFR1-Fc fusion protein. FGFR and EGFR-dependence was defined by sensitivity to multiple inhibitors selective for FGFRs or EGFR. Results FGF2 was expressed in eight of the nine HNSCC cell lines examined. Also, FGFR2 and FGFR3 were frequently expressed while only two lines expressed FGFR1. FP-1039 inhibited growth of HNSCC cell lines expressing FGF2, identifying FGF2 as an autocrine growth factor. FGFR inhibitors selectively reduced in vitro growth and ERK signaling in three HNSCC cell lines while three distinct lines exhibited responsiveness to both EGFR and FGFR inhibitors. Combinations of these drugs yielded additive growth inhibition. Finally, three cell lines were highly sensitive to EGFR TKIs with no contribution from FGFR pathways. Conclusions FGFR signaling was dominant or co-dominant with EGFR in six HNSCC lines while three lines exhibited little or no role for FGFRs and were highly EGFR-dependent. Thus, the HNSCC cell lines can be divided into subsets defined by sensitivity to EGFR and FGFR-specific TKIs. FGFR inhibitors may represent novel therapeutics to deploy alone or in combination with EGFR inhibitors in HNSCC. PMID:21673064

Pregnenolone can protect the brain from cannabis intoxication.

PubMed

Vallée, Monique; Vitiello, Sergio; Bellocchio, Luigi; Hébert-Chatelain, Etienne; Monlezun, Stéphanie; Martin-Garcia, Elena; Kasanetz, Fernando; Baillie, Gemma L; Panin, Francesca; Cathala, Adeline; Roullot-Lacarrière, Valérie; Fabre, Sandy; Hurst, Dow P; Lynch, Diane L; Shore, Derek M; Deroche-Gamonet, Véronique; Spampinato, Umberto; Revest, Jean-Michel; Maldonado, Rafael; Reggio, Patricia H; Ross, Ruth A; Marsicano, Giovanni; Piazza, Pier Vincenzo

2014-01-03

Pregnenolone is considered the inactive precursor of all steroid hormones, and its potential functional effects have been largely uninvestigated. The administration of the main active principle of Cannabis sativa (marijuana), Δ(9)-tetrahydrocannabinol (THC), substantially increases the synthesis of pregnenolone in the brain via activation of the type-1 cannabinoid (CB1) receptor. Pregnenolone then, acting as a signaling-specific inhibitor of the CB1 receptor, reduces several effects of THC. This negative feedback mediated by pregnenolone reveals a previously unknown paracrine/autocrine loop protecting the brain from CB1 receptor overactivation that could open an unforeseen approach for the treatment of cannabis intoxication and addiction.

Rhythmic control of endocannabinoids in the rat pineal gland.

PubMed

Koch, Marco; Ferreirós, Nerea; Geisslinger, Gerd; Dehghani, Faramarz; Korf, Horst-Werner

2015-01-01

Endocannabinoids modulate neuroendocrine networks by directly targeting cannabinoid receptors. The time-hormone melatonin synchronizes these networks with external light condition and guarantees time-sensitive and ecologically well-adapted behaviors. Here, the endocannabinoid arachidonoyl ethanolamide (AEA) showed rhythmic changes in rat pineal glands with higher levels during the light-period and reduced amounts at the onset of darkness. Norepinephrine, the essential stimulus for nocturnal melatonin biosynthesis, acutely down-regulated AEA and other endocannabinoids in cultured pineal glands. These temporal dynamics suggest that AEA exerts time-dependent autocrine and/or paracrine functions within the pineal. Moreover, endocananbinoids may be released from the pineal into the CSF or blood stream.

Cytokines in the central nervous system: regulatory roles in neuronal function, cell death and repair.

PubMed

Sei, Y; Vitković, L; Yokoyama, M M

1995-01-01

Recent evidence suggests that neurons and glia can synthesize and secrete cytokines, which play critical roles in maintaining homeostasis in the central nervous system (CNS) by mediating the interaction between cells via autocrine or paracrine mechanisms. Circulating cytokines and soluble receptors also regulate neuronal function via endocrine mechanisms. Disturbance of the cytokine-mediated interaction between cells may lead to neuronal dysfunction and/or cell death and contribute to the pathogenesis of the CNS diseases (e.g., ischemia, Alzheimer's disease and HIV encephalopathy). Defining the molecular pathways of cytokine dysregulation and neurotoxicity may help to elucidate potential therapeutic interventions for many devastating CNS diseases.

The Role of Semaphorin 3B (SEMA3B) in the Pathogenesis of Breast Cancer

DTIC Science & Technology

2006-04-01

apoptotic and anti-proliferative effect on cancer lines it is in part by the inhibition of Akt pathway. In conclusion, we hypothesize that VEGF165...autocrine activity and by inhibiting the Akt pathway. 15. SUBJECT TERMS tumor suppressor gene, breast cancer and apoptosis 16. SECURITY...TGFβ TGFR2 Smad4 M D A M B A 54 9 H 12 99 H el a H 46 0 M C F7 ZR -7 5 H 15 7 2 31 GAPDH TGFR1 B. C 2H 24H 48H 72H SEMA3B SEMA3B

The relationship of urocortin-2 with insulin resistance patients having PCOS.

PubMed

Temur, Muzaffer; Yılmaz, Özgür; Aksun, Saliha; Calan, Mehmet; Özün Özbay, Pelin; Kumbasar, Serkan; Sever, Erman

2017-02-01

In this study, we aimed to compare the serum urocortin-2 (UCN2) levels in women with polycystic ovary syndrome (PCOS) and healthy women. Thirty-eight patients with PCOS and 41 healthy women were included in the study whose age and BMI matched. The fasting serum glucose, insulin, free testosterone, hs-CRP and UCN2 levels of the all participants were examined. HOMA-IR formula was used in order to calculate the insulin resistance. Circulating UCN2 levels were significantly elevated in women with PCOS compared with controls (142.93 ± 59.48 versus 98.56 ± 65.01 pg/ml, p = 0.002). FBG, serum insulin, hs-CRP and HOMA-IR levels were found to be increased in women with PCOS. There was a positive correlation between UCN2 and free-testosterone in only PCOS group (r = 0.235, p = 0.027). Multivariate logistic regression analyses revealed that the odds ratio for PCOS was 2.31 for patients in the highest quartile of UCN2 compared with those in the lowest quartile (OR = 2.31, 95% CI = 1.88-2.83, p=0.021). Multiple linear regression analysis revealed that HOMA-IR, hs-CRP and free-testosterone independently predicted UCN2 levels (p < 0.05). UCN2 levels were significantly higher in PCOS cases when compared to control group. UCN2 is thought to be effective on pathophysiology of PCOS by paracrine and autocrine pathways.

Control of Wnt Receptor Turnover by R-spondin-ZNRF3/RNF43 Signaling Module and Its Dysregulation in Cancer.

PubMed

Hao, Huai-Xiang; Jiang, Xiaomo; Cong, Feng

2016-06-08

Aberrant activation of the Wnt/β-catenin pathway is frequently found in various cancers, often through mutations of downstream components. Inhibiting β-catenin signaling in tumors with downstream pathway mutations remains challenging, due to a lack of favorable targets. On the other hand, targeting upstream components of the Wnt pathway is rather straightforward. However, it is difficult to identify tumors addicted to autocrine or paracrine Wnt signaling. Discovery of the R-spondin-ZNRF3/RNF43 signaling module and its genetic alterations in cancers represents a breakthrough in this area. Membrane E3 ligase ZNRF3 and RNF43 are critical negative feedback regulators of the Wnt pathway, which function through promoting ubiquitination and degradation of Wnt receptors. R-spondin proteins (RSPO1-4) serve as natural antagonists of ZNRF3/RNF43. To maintain strong and sustained Wnt/β-catenin signaling, cancers need to overcome ZNRF3/RNF43-mediated feedback inhibition. Indeed, mutations of RNF43/ZNRF3 and recurrent translocations of RSPO2/RSPO3 have recently been identified in various cancers. Significantly, genetic alterations in RNF43/ZNRF3/RSPO2/RSPO3 have shown promise as predictive biomarkers in pre-clinical models for the efficacy of upstream Wnt inhibitors. In this review, we will discuss the biology of the R-spondin-ZNRF3/RNF43 signaling module, cancer-associated alterations of this signaling module, and their value as biomarkers to identify Wnt-addicted tumors.

Control of Wnt Receptor Turnover by R-spondin-ZNRF3/RNF43 Signaling Module and Its Dysregulation in Cancer

PubMed Central

Hao, Huai-Xiang; Jiang, Xiaomo; Cong, Feng

2016-01-01

Aberrant activation of the Wnt/β-catenin pathway is frequently found in various cancers, often through mutations of downstream components. Inhibiting β-catenin signaling in tumors with downstream pathway mutations remains challenging, due to a lack of favorable targets. On the other hand, targeting upstream components of the Wnt pathway is rather straightforward. However, it is difficult to identify tumors addicted to autocrine or paracrine Wnt signaling. Discovery of the R-spondin-ZNRF3/RNF43 signaling module and its genetic alterations in cancers represents a breakthrough in this area. Membrane E3 ligase ZNRF3 and RNF43 are critical negative feedback regulators of the Wnt pathway, which function through promoting ubiquitination and degradation of Wnt receptors. R-spondin proteins (RSPO1-4) serve as natural antagonists of ZNRF3/RNF43. To maintain strong and sustained Wnt/β-catenin signaling, cancers need to overcome ZNRF3/RNF43-mediated feedback inhibition. Indeed, mutations of RNF43/ZNRF3 and recurrent translocations of RSPO2/RSPO3 have recently been identified in various cancers. Significantly, genetic alterations in RNF43/ZNRF3/RSPO2/RSPO3 have shown promise as predictive biomarkers in pre-clinical models for the efficacy of upstream Wnt inhibitors. In this review, we will discuss the biology of the R-spondin-ZNRF3/RNF43 signaling module, cancer-associated alterations of this signaling module, and their value as biomarkers to identify Wnt-addicted tumors. PMID:27338477

Identification of a novel FN1-FGFR1 genetic fusion as a frequent event in phosphaturic mesenchymal tumour.

PubMed

Lee, Jen-Chieh; Jeng, Yung-Ming; Su, Sheng-Yao; Wu, Chen-Tu; Tsai, Keh-Sung; Lee, Cheng-Han; Lin, Chung-Yen; Carter, Jodi M; Huang, Jenq-Wen; Chen, Shu-Hwa; Shih, Shyang-Rong; Mariño-Enríquez, Adrián; Chen, Chih-Chi; Folpe, Andrew L; Chang, Yih-Leong; Liang, Cher-Wei

2015-03-01

Phosphaturic mesenchymal tumours (PMTs) are uncommon soft tissue and bone tumours that typically cause hypophosphataemia and tumour-induced osteomalacia (TIO) through secretion of phosphatonins including fibroblast growth factor 23 (FGF23). PMT has recently been accepted by the World Health Organization as a formal tumour entity. The genetic basis and oncogenic pathways underlying its tumourigenesis remain obscure. In this study, we identified a novel FN1-FGFR1 fusion gene in three out of four PMTs by next-generation RNA sequencing. The fusion transcripts and proteins were subsequently confirmed with RT-PCR and western blotting. Fluorescence in situ hybridization analysis showed six cases with FN1-FGFR1 fusion out of an additional 11 PMTs. Overall, nine out of 15 PMTs (60%) harboured this fusion. The FN1 gene possibly provides its constitutively active promoter and the encoded protein's oligomerization domains to overexpress and facilitate the activation of the FGFR1 kinase domain. Interestingly, unlike the prototypical leukaemia-inducing FGFR1 fusion genes, which are ligand-independent, the FN1-FGFR1 chimeric protein was predicted to preserve its ligand-binding domains, suggesting an advantage of the presence of its ligands (such as FGF23 secreted at high levels by the tumour) in the activation of the chimeric receptor tyrosine kinase, thus effecting an autocrine or a paracrine mechanism of tumourigenesis. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Endothelin therapeutics in cancer: Where are we?

PubMed

Rosanò, Laura; Bagnato, Anna

2016-03-15

In human cancers, the autocrine and paracrine loop mediated by the aberrantly activation of endothelin-1 (ET-1) receptor (ET-1R) elicits pleiotropic effects, preferentially mediated by the scaffold protein β-arrestin 1 (β-arr1), on tumor cells and on the host microenvironment, providing a strong rationale for targeting ET-1 receptors. This review describes the most up-to-date preclinical and clinical results obtained by using ET-1 therapeutics. The previous negative clinical results of ET-1 therapeutics should not prevent us from setting the standard of this class of drugs for future well-designed clinical trials. The preclinical data obtained with the dual ETAR and ETBR antagonist macitentan indicate that this molecule, which targets cancer cells and tumor-associated microenvironmental elements, could be a cancer therapeutic option. The field of ET-1 therapeutics will be improved in the next decade, facilitated by the new knowledge on the genomic landscape of the human stroma and tumor, and by the low invasive approaches based on liquid biopsies for the discovery of predictive biomarkers. The information obtained from preclinical studies in patient-derived models and from the Cancer Genome Atlas will set the scene of precision medicine for cancer. Results from these studies are expected to open the possibility that ET-1R antagonists might be more efficacious as molecular cancer therapeutics, able to hamper the functional β-arr1-dependent signaling complexes, either alone or coupled with new targeted approaches. Copyright © 2016 the American Physiological Society.

Purines and neuronal excitability: links to the ketogenic diet.

PubMed

Masino, S A; Kawamura, M; Ruskin, D N; Geiger, J D; Boison, D

2012-07-01

ATP and adenosine are purines that play dual roles in cell metabolism and neuronal signaling. Acting at the A(1) receptor (A(1)R) subtype, adenosine acts directly on neurons to inhibit excitability and is a powerful endogenous neuroprotective and anticonvulsant molecule. Previous research showed an increase in ATP and other cell energy parameters when an animal is administered a ketogenic diet, an established metabolic therapy to reduce epileptic seizures, but the relationship among purines, neuronal excitability and the ketogenic diet was unclear. Recent work in vivo and in vitro tested the specific hypothesis that adenosine acting at A(1)Rs is a key mechanism underlying the success of ketogenic diet therapy and yielded direct evidence linking A(1)Rs to the antiepileptic effects of a ketogenic diet. Specifically, an in vitro mimic of a ketogenic diet revealed an A(1)R-dependent metabolic autocrine hyperpolarization of hippocampal neurons. In parallel, applying the ketogenic diet in vivo to transgenic mouse models with spontaneous electrographic seizures revealed that intact A(1)Rs are necessary for the seizure-suppressing effects of the diet. This is the first direct in vivo evidence linking A(1)Rs to the antiepileptic effects of a ketogenic diet. Other predictions of the relationship between purines and the ketogenic diet are discussed. Taken together, recent research on the role of purines may offer new opportunities for metabolic therapy and insight into its underlying mechanisms. Copyright © 2011 Elsevier B.V. All rights reserved.

ONC201: Stressing tumors to death.

PubMed

Endo Greer, Yoshimi; Lipkowitz, Stanley

2016-02-16

The small molecule ONC201 was identified in a screen for compounds that would induce expression of the gene encoding tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in tumors and thus cause an autocrine- or paracrine-induced death in tumor cells. Two Research Articles in this issue of Science Signaling by Ishizawa et al. and Kline et al. describe how ONC201 can also trigger cytotoxicity by inducing a stress response. The mechanisms of the stress response induced differ between hematological malignancies and solid tumors, highlighting the complexity of ONC201-induced toxicity and raising intriguing issues of tissue-specific pathways activated by the drug. Copyright © 2016, American Association for the Advancement of Science.

Natriuretic Peptides as Biomarkers in Heart Failure

PubMed Central

Januzzi, James L.

2014-01-01

Following the initial discovery of a natriuretic and diuretic peptide factor present in atrial myocardial tissue homogenates, subsequent elucidation of the natriuretic peptide family has led to substantial advances in the understanding of the autocrine, paracrine, and endocrine regulation of the cardiovascular system. Furthermore, with the development of assays for the measurement of the natriuretic peptides, these important biomarkers have gone from being regarded as biological mediators of the cardiovascular system to now represent important clinical tools for the diagnostic and prognostic evaluation of patients with heart failure, and may have potential as a therapeutic target in this setting as well. An historical perspective on the natriuretic peptides from bench to bedside translation will be discussed. PMID:23661103

Interaction of tumor and host cells with adhesion and extracellular matrix molecules in the development of multiple myeloma.

PubMed

Teoh, G; Anderson, K C

1997-02-01

Adhesion molecules play an important role in the growth regulation and migration of multiple myeloma (MM) cells. They mediate homing of MM cells to the bone marrow and MM cell to bone marrow stromal cell adhesion, with resultant interleukin-6 related autocrine and paracine growth and antiapoptotic affects. Their pattern of expression on tumor cells correlates with the development of plasma cell leukemia or extramedullary disease. Clinically, expression of adhesion molecules on tumor cells or in the serum has already shown prognostic utility. Finally, since adhesion molecules are involved at multiple steps in the pathogenesis of MM, therapeutic studies may target these molecules.

Prognostic factors of craniopharyngioma with special reference to autocrine/paracrine signaling: underestimated implication of growth hormone receptor.

PubMed

Ogawa, Yoshikazu; Watanabe, Mika; Tominaga, Teiji

2015-10-01

Craniopharyngioma is a slow-growing tumor classified as benign, but tight adhesion and significant local infiltration to the vital structures are common. In spite of improvement of modern microsurgery techniques and precise anatomical understanding not few cases of this tumor recur, and long-term tumor control and maintenance of quality of life are sometimes difficult. However, very little is known about the effects of the molecular characters of craniopharyngioma on the prognosis. Ninety eight cases of craniopharyngioma surgically treated at the Department of Neurosurgery, Tohoku University Hospital and Kohnan Hospital from April 1996 to May 2014, 45 males and 53 females aged from 2 to 80 years (mean, 40.84 years) were retrospectively reviewed, and postoperative outcomes and the possible involvement of the autocrine/paracrine mechanism were investigated. The patients were followed up at intervals of 6 months to assess tumor recurrence, and clinical outcomes were correlated with the findings of immunohistochemical examinations used growth hormone receptor (GHR) and downstream hormones. The follow-up period ranged from 3 to 209 months. Hormone expression was examined in 88 patients, of which 46 specimens (52.3 %) showed high expression of GHR. The GHR high expression group had a significantly shorter duration of postoperative stable disease compared with the low expression group (logrank test, p = 0.007). Simultaneous high expression of growth hormone (GH) and GHR was found in 33 specimens (37.5 %), and the high expression group had a significantly shorter duration of postoperative stable disease compared with the low expression group (logrank test, p = 0.011). No other hormones showed statistically significant differences in outcomes. High expression of GHR is associated with shorter duration of postoperative stable disease in patients with craniopharyngioma. If the surgical specimens were craniopharyngiomas with high GHR expression, GH supplementation would be introduced quite prudently.

Novel Insights into the Cardio-Protective Effects of FGF21 in Lean and Obese Rat Hearts

PubMed Central

Chen, Jing; Ramanjaneya, Manjunath; Bari, Muhammad F.; Bhudia, Sunil K.; Hillhouse, Edward W.; Tan, Bee K.; Randeva, Harpal S.

2014-01-01

Aims Fibroblast growth factor 21 (FGF21) is a hepatic metabolic regulator with pleotropic actions. Its plasma concentrations are increased in obesity and diabetes; states associated with an increased incidence of cardiovascular disease. We therefore investigated the direct effect of FGF21 on cardio-protection in obese and lean hearts in response to ischemia. Methods and Results FGF21, FGF21-receptor 1 (FGFR1) and beta-Klotho (βKlotho) were expressed in rodent, human hearts and primary rat cardiomyocytes. Cardiac FGF21 was expressed and secreted (real time RT-PCR/western blot and ELISA) in an autocrine-paracrine manner, in response to obesity and hypoxia, involving FGFR1-βKlotho components. Cardiac-FGF21 expression and secretion were increased in response to global ischemia. In contrast βKlotho was reduced in obese hearts. In isolated adult rat cardiomyocytes, FGF21 activated PI3K/Akt (phosphatidylinositol 3-kinase/Akt), ERK1/2(extracellular signal-regulated kinase) and AMPK (AMP-activated protein kinase) pathways. In Langendorff perfused rat [adult male wild-type wistar] hearts, FGF21 administration induced significant cardio-protection and restoration of function following global ischemia. Inhibition of PI3K/Akt, AMPK, ERK1/2 and ROR-α (retinoic-acid receptor alpha) pathway led to significant decrease of FGF21 induced cardio-protection and restoration of cardiac function in response to global ischemia. More importantly, this cardio-protective response induced by FGF21 was reduced in obesity, although the cardiac expression profiles and circulating FGF21 levels were increased. Conclusion In an ex vivo Langendorff system, we show that FGF21 induced cardiac protection and restoration of cardiac function involving autocrine-paracrine pathways, with reduced effect in obesity. Collectively, our findings provide novel insights into FGF21-induced cardiac effects in obesity and ischemia. PMID:24498293

Expression pattern and phosphorylation status of Smad2/3 in different subtypes of human first trimester trophoblast.

PubMed

Haider, S; Kunihs, V; Fiala, C; Pollheimer, J; Knöfler, M

2017-09-01

TGF-β superfamily members are thought to play a pivotal role in placental development and differentiation. However, their downstream effectors, the Smad transcription factors, have been poorly investigated in human trophoblasts. Expression and localisation of the canonical TGF-β targets Smad2/3 and their regulators (Smad4 and Smad7) were investigated in first trimester placenta and purified cytotrophoblast (CTB) subtypes using immunofluorescence, western blotting and qPCR. Canonical and non-canonical activation was analysed in nuclear/cytoplasmic extracts of trophoblast subtypes as well as in tissue sections using antibodies against Smad2/3, phosphorylated either at the C-terminus (pSmad2C/3C) or in their linker regions (pSmad2L/3L). Smad phosphorylation was also examined in differentiating extravillous trophoblasts (EVTs) in the absence or presence of decidual stromal cell (DSC)-conditioned medium. Smad2, Smad4 and Smad7 protein were uniformly expressed between 6th and 12th week placentae and the different isolated CTB subtypes. Activated pSmad2L was mainly detected in nuclei and cytoplasm of villous CTBs, whereas pSmad2C was absent from these cells. In contrast, pSmad2C could be detected in the cytoplasm of cell column trophoblasts and in the cytoplasm/nuclei of EVTs. Smad3 and its phosphorylated forms pSmad3C and pSmad3L specifically localised to EVT nuclei. During EVT differentiation autocrine activation of pSmad2C/3C and pSmad3L was observed. DSC-conditioned medium further increased Smad2/3 phosphorylation in EVTs. The lack of pSmad2C in villous CTBs suggests that other mitogens than TGF-β could promote Smad2 linker phosphorylation under homeostatic conditions. Whereas autocrine signalling activates Smad2/3 in differentiating EVTs, paracrine factors contribute to Smad phosphorylation in these cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Autocrine Extra-Pancreatic Trypsin 3 Secretion Promotes Cell Proliferation and Survival in Esophageal Adenocarcinoma

PubMed Central

Han, Song; Lee, Constance W.; Trevino, Jose G.; Hughes, Steven J.; Sarosi, George A.

2013-01-01

Trypsin or Tumor associated trypsin (TAT) activation of Protease-activated receptor 2 (PAR-2) promotes tumor cell proliferation in gastrointestinal cancers. The role of the trypsin/PAR-2 network in esophageal adenocarcinoma (EA) development has not yet been investigated. The aim of this study is to investigate the role of trypsin/PAR-2 activation in EA tumorogenesis and therapy. We found that esophageal adenocarcinoma cells (EACs) and Barrett’s Metaplasia (BART) expressed high levels of type 3 extra-pancreatic trypsinogen (PRSS3), a novel type of TAT. Activity of secreted trypsin was detected in cultured media from EA OE19 and OE33 cultures but not from BART culture. Surface PAR-2 expression in BART and EACs was confirmed by both flow cytometry and immunofluorescence. Trypsin induced cell proliferation (∼ 2 fold; P<0.01) in all tested cell lines at a concentration of 10 nM. Inhibition of PAR-2 activity in EACs via the PAR-2 antagonist ENMD (500 µM), anti-PAR2 antibody SAM-11 (2 µg/ml), or siRNA PAR-2 knockdown, reduced cell proliferation and increased apoptosis by up to 4 fold (P<0.01). Trypsin stimulation led to phosphorylation of ERK1/2, suggesting involvement of MAPK pathway in PAR-2 signal transduction. Inhibition of PAR-2 activation or siRNA PAR-2 knockdown in EACs prior to treatment with 5 FU reduced cell viability of EACs by an additional 30% (P<0.01) compared to chemotherapy alone. Our data suggest that extra-pancreatic trypsinogen 3 is produced by EACs and activates PAR-2 in an autocrine manner. PAR-2 activation increases cancer cell proliferation, and promotes cancer cell survival. Targeting the trypsin activated PAR-2 pathway in conjunction with current chemotherapeutic agents may be a viable therapeutic strategy in EA. PMID:24146905

A moderately low phosphate intake may provide health benefits analogous to those conferred by UV light - a further advantage of vegan diets.

PubMed

McCarty, M F

2003-01-01

Although exposure to ultraviolet light is often viewed as pathogenic owing to its role in the genesis of skin cancer and skin aging, there is growing epidemiological evidence that such exposure may decrease risk for a number of more serious cancers, may have a favorable impact on blood pressure and vascular health, and may help to prevent certain autoimmune disorders - in addition to its well-known influence on bone density. Most likely, these health benefits are reflective of improved vitamin D status. Increased synthesis or intake of vitamin D can be expected to down-regulate parathyroid hormone (PTH), and to increase autocrine synthesis of its active metabolite calcitriol in certain tissues; these effects, in turn, may impact cancer risk, vascular health, immune regulation, and bone density through a variety of mechanisms. Presumably, a truly adequate supplemental intake of vitamin D - manyfold higher than the grossly inadequate current RDA - could replicate the benefits of optimal UV exposure, without however damaging the skin. Diets moderately low in bioavailable phosphate - like many vegan diets - might be expected to have a complementary impact on disease risks, inasmuch as serum phosphate suppresses renal calcitriol synthesis while up-regulating that of PTH. A proviso is that the impact of dietary phosphorus on bone health is more equivocal than that of vitamin D. Increased intakes of calcium, on the other hand, down-regulate the production of both PTH and calcitriol - the latter effect may explain why the impact of dietary calcium on cancer risk (excepting colon cancer), hypertension, and autoimmunity is not clearly positive. An overview suggests that a vegan diet supplemented with high-dose vitamin D should increase both systemic and autocrine calcitriol production while suppressing PTH secretion, and thus should represent a highly effective way to achieve the wide-ranging health protection conferred by optimal UV exposure.

An antigen receptor-driven, interleukin 2-independent pathway for proliferation of murine cytolytic T lymphocyte clones

PubMed Central

1986-01-01

Proliferation of T lymphocytes can be induced by IL-2, either through an autocrine pathway in which the responding cell produces its own IL-2 or through an exocrine pathway in which IL-2 secreted by Th stimulates proliferation of IL-2-dependent CTL. However, proliferation of at least some CTL clones, such as CTL L3 and CTL dB45, also can be induced by stimulation of the antigen receptor in the absence of IL-2. Stimulation of these cloned CTL with T cell-depleted allogeneic spleen cells, allogeneic tumor cells, or immobilized mAb reactive with the T cell antigen receptor (TCR) induced thymidine incorporation, entry into cell cycle, and secretion of macrophage activating factor, but these stimuli did not induce the secretion of IL-2. Several observations indicated that such proliferation of cloned CTL induced by stimulation of the TCR was independent of IL-2; IL-2 could not be detected in supernatants from stimulated CTL cells. mAbs reactive with the murine IL-2-R efficiently blocked IL-2-mediated thymidine incorporation in cloned CTL and Th, but had no inhibitory effect on TCR-driven thymidine incorporation in the CTL clones. TCR-driven thymidine incorporation in cloned Th L2 cells was profoundly inhibited by these antibodies, indicating the operation of an IL-2-mediated autocrine pathway for proliferation in this cloned Th. When antibodies to the TCR were used to stimulate cloned CTL and Th, IFN-gamma mRNA was easily shown in the cloned CTL and Th. Although IL-2 mRNA could be detected in the cloned Th, it was never observed in the cloned CTL. These findings provide evidence for the existence of a TCR-mediated, IL-2-independent pathway for induction of cellular proliferation in cloned murine CTL. PMID:3486939

Hyaluronan up-regulates growth and invasion of trophoblasts in an autocrine manner via PI3K/AKT and MAPK/ERK1/2 pathways in early human pregnancy.

PubMed

Zhu, R; Huang, Y-H; Tao, Y; Wang, S-C; Sun, Ch; Piao, H-L; Wang, X-Q; Du, M-R; Li, D-J

2013-09-01

As one of the key molecules in the extracellular matrix in human conceptus, hyaluronan (HA) has been receiving particular attention. Here, we have investigated the expression and regulation of different molecular weight HA on the biological behaviors of primary human trophoblasts during the first trimester of pregnancy. The expression of HA and HA synthetase (HAS) by human first trimester trophoblasts was analyzed in placentae from normal pregnancy or miscarriage by immunochemistry and real-time RT-PCR, respectively. ELISA was used to measure the secretion of HA by primary trophoblasts. The effects of HA on the proliferation, apoptosis and invasiveness of trophoblasts were examined. We also investigated the signaling pathways involved in HA activation in human trophoblasts. The higher HAS2 expression and HA secretion were observed in normal villi than that of miscarriage, and the primary trophoblasts secreted HA continuously. High molecular weight HA (HMW-HA) and medium molecular weight HA (MMW-HA) promoted proliferation and invasiveness while inhibited apoptosis of trophoblasts. However, low molecular weight HA (LMW-HA) had no obvious effect on the growth or invasiveness of human trophoblasts. In addition, HMW-HA showed more efficiently than MMW-HA on the growth while MMW-HA displayed a more obvious effect on the invasiveness of trophoblasts than HMW-HA. HMW-HA activated PI3K/AKT and MAPK/ERK1/2 signaling pathways in trophoblasts. Blocking PI3K/AKT or MAPK/ERK1/2 signaling inhibited the HA-upregulated growth and invasiveness of human trophoblasts. Our results suggest that higher level and greater molecular mass of HA can promote trophoblast growth and invasion in an autocrine manner, which was beneficial to placentation and maintenance of human early pregnancy. Copyright © 2013 Elsevier Ltd. All rights reserved.

Coordinate tropic hormone regulation of mRNAs for insulin-like growth factor II and the cholesterol side-chain-cleavage enzyme, P450scc [corrected], in human steroidogenic tissues.

PubMed Central

Voutilainen, R; Miller, W L

1987-01-01

Insulin-like growth factors (IGFs) are single-chain polypeptides important for cell proliferation and growth. IGFs are produced in several tissues, suggesting that they function in a paracrine or autocrine fashion as well as functioning as endocrine hormones. We studied the hormonal regulation of IGF-I and IGF-II mRNA in human steroidogenic tissues. In cultured human ovarian granulosa cells, follicle-stimulating hormone, human chorionic gonadotropin, and dibutyryl cAMP increased IGF-II mRNA, but corticotropin [adrenocorticotropic hormone (ACTH)], chorionic somatomammotropin, growth hormone, prolactin, dexamethasone, estradiol, and progesterone had no effect. In cultured human fetal adrenal cells, ACTH and dibutyryl cAMP increased IGF-II mRNA accumulation, but human chorionic gonadotropin and angiotensin II did not. The same five size species of IGF-II mRNA were detected in transfer blots of RNA from granulosa cells and fetal adrenal cells, and all of these increased after hormonal stimuli. Dibutyryl cAMP also increased IGF-II mRNA accumulation in cultured human placental cells. Accumulation of mRNA for the cholesterol side-chain-cleavage monooxygenase [P450scc [corrected]; cholesterol, reduced-adrenal-ferredoxin:oxygen oxidoreductase (side-chain-cleaving), EC 1.14.15.6] was regulated in parallel with IGF-II mRNA in all these steroidogenic tissues. IGF-I mRNA was not detected in transfer blots of these RNAs, and the minimal amounts detected in dot blots showed no detectable change after any of the hormonal stimuli studied. The data indicate that the IGF-II gene is expressed in human steroidogenic tissues and is regulated by cAMP. These data suggest that IGF-II may act in an autocrine or paracrine fashion to stimulate the adrenal and gonadal growth stimulated by ACTH and gonadotropins, respectively. Images PMID:3031644

Autocrine expression of the epidermal growth factor receptor ligand heparin-binding EGF-like growth factor in cervical cancer.

PubMed

Schrevel, Marlies; Osse, E Michelle; Prins, Frans A; Trimbos, J Baptist M Z; Fleuren, Gert Jan; Gorter, Arko; Jordanova, Ekaterina S

2017-06-01

In cervical cancer, the epidermal growth factor receptor (EGFR) is overexpressed in 70-90% of the cases and has been associated with poor prognosis. EGFR-based therapy is currently being explored in cervical cancer. We investigated which EGFR ligand is primarily expressed in cervical cancer and which cell type functions as the major source of this ligand. We hypothesized that macrophages are the main source of EGFR ligands and that a paracrine loop between tumor cells and macrophages is responsible for ligand expression. mRNA expression analysis was performed on 32 cervical cancer cases to determine the expression of the EGFR ligands amphiregulin, β-cellulin, epidermal growth factor (EGF), epiregulin, heparin-binding EGF-like growth factor (HB‑EGF) and transforming growth factor α (TGFα). Subsequently, protein expression was determined immunohistochemically on 36 additional cases. To assess whether macrophages are the major source of EGFR ligands, immunohistochemical double staining was performed on four representative tissue slides. Expression of the chemokines granulocyte-macrophage colony-stimulating factor (GM-CSF) and C-C motif ligand 2 (CCL2) was determined by mRNA in situ hybridization. Of the known EGFR ligands, HB‑EGF had the highest mRNA expression and HB‑EGF and EGFR protein expression were highly correlated. Tumor specimens with high EGFR expression showed higher numbers of macrophages, and higher expression of GM-CSF and CCL2, but only a small subset (9%) of macrophages was found to be HB‑EGF-positive. Strikingly, 78% of cervical cancer specimens were found to express HB‑EGF. Standardized assessment of staining intensity, using spectral imaging analysis, showed that HB‑EGF expression was higher in the tumor compartment than in the stromal compartment. These results suggest that HB‑EGF is an important EGFR ligand in cervical cancer and that cervical cancer cells are the predominant source of HB‑EGF. Therefore, we propose an autocrine EGFR stimulation model in cervical carcinomas.

Autocrine Complement Inhibits IL10-Dependent T-cell-Mediated Antitumor Immunity to Promote Tumor Progression.

PubMed

Wang, Yu; Sun, Sheng-Nan; Liu, Qing; Yu, Yang-Yang; Guo, Jian; Wang, Kun; Xing, Bao-Cai; Zheng, Qing-Feng; Campa, Michael J; Patz, Edward F; Li, Shi-You; He, You-Wen

2016-09-01

In contrast to its inhibitory effects on many cells, IL10 activates CD8(+) tumor-infiltrating lymphocytes (TIL) and enhances their antitumor activity. However, CD8(+) TILs do not routinely express IL10, as autocrine complement C3 inhibits IL10 production through complement receptors C3aR and C5aR. CD8(+) TILs from C3-deficient mice, however, express IL10 and exhibit enhanced effector function. C3-deficient mice are resistant to tumor development in a T-cell- and IL10-dependent manner; human TILs expanded with IL2 plus IL10 increase the killing of primary tumors in vitro compared with IL2-treated TILs. Complement-mediated inhibition of antitumor immunity is independent of the programmed death 1/programmed death ligand 1 (PD-1/PD-L1) immune checkpoint pathway. Our findings suggest that complement receptors C3aR and C5aR expressed on CD8(+) TILs represent a novel class of immune checkpoints that could be targeted for tumor immunotherapy. Moreover, incorporation of IL10 in the expansion of TILs and in gene-engineered T cells for adoptive cell therapy enhances their antitumor efficacy. Our data suggest novel strategies to enhance immunotherapies: a combined blockade of complement signaling by antagonists to C3aR, C5aR, and anti-PD-1 to enhance anti-PD-1 efficacy; a targeted IL10 delivery to CD8(+) TILs using anti-PD-1-IL10 or anti-CTLA4-IL10 fusion proteins; and the addition of IL10 in TIL expansion for adoptive cellular therapy. Cancer Discov; 6(9); 1022-35. ©2016 AACR.See related commentary by Peng et al., p. 953This article is highlighted in the In This Issue feature, p. 932. ©2016 American Association for Cancer Research.

Reactive Oxygen Species/Hypoxia-Inducible Factor-1α/Platelet-Derived Growth Factor-BB Autocrine Loop Contributes to Cocaine-Mediated Alveolar Epithelial Barrier Damage

PubMed Central

Yang, Lu; Chen, Xufeng; Simet, Samantha M.; Hu, Guoku; Cai, Yu; Niu, Fang; Kook, Yeonhee

2016-01-01

Abuse of psychostimulants, such as cocaine, has been shown to be closely associated with complications of the lung, such as pulmonary hypertension, edema, increased inflammation, and infection. However, the mechanism by which cocaine mediates impairment of alveolar epithelial barrier integrity that underlies various pulmonary complications has not been well determined. Herein, we investigate the role of cocaine in disrupting the alveolar epithelial barrier function and the associated signaling cascade. Using the combinatorial electric cell–substrate impedance sensing and FITC-dextran permeability assays, we demonstrated cocaine-mediated disruption of the alveolar epithelial barrier, as evidenced by increased epithelial monolayer permeability with a concomitant loss of the tight junction protein zonula occludens-1 (Zo-1) in both mouse primary alveolar epithelial cells and the alveolar epithelial cell line, L2 cells. To dissect the signaling pathways involved in this process, we demonstrated that cocaine-mediated induction of permeability factors, platelet-derived growth factor (PDGF-BB) and vascular endothelial growth factor, involved reactive oxygen species (ROS)-dependent induction of hypoxia-inducible factor (HIF)-1α. Interestingly, we demonstrated that ROS-dependent induction of another transcription factor, nuclear factor erythroid-2–related factor-2, that did not play a role in cocaine-mediated barrier dysfunction. Importantly, this study identifies, for the first time, that ROS/HIF-1α/PDGF-BB autocrine loop contributes to cocaine-mediated barrier disruption via amplification of oxidative stress and downstream signaling. Corroboration of these cell culture findings in vivo demonstrated increased permeability of the alveolar epithelial barrier, loss of expression of Zo-1, and a concomitantly increased expression of both HIF-1α and PDGF-BB. Pharmacological blocking of HIF-1α significantly abrogated cocaine-mediated loss of Zo-1. Understanding the mechanism(s) by which cocaine mediates barrier dysfunction could provide insights into the development of potential therapeutic targets for cocaine-mediated pulmonary hypertension. PMID:27391108

CpG oligodeoxynucleotide induces apoptosis and cell cycle arrest in A20 lymphoma cells via TLR9-mediated pathways.

PubMed

Qi, Xu-Feng; Zheng, Li; Kim, Cheol-Su; Lee, Kyu-Jae; Kim, Dong-Heui; Cai, Dong-Qing; Qin, Jun-Wen; Yu, Yan-Hong; Wu, Zheng; Kim, Soo-Ki

2013-07-01

Recent studies have suggested that the anti-cancer activity of CpG-oligodeoxynucleotides (CpG-ODNs) is owing to their immunomodulatory effects in tumor-bearing host. The purpose of this study is to investigate the directly cytotoxic activity of KSK-CpG, a novel CpG-ODN with an alternative CpG motif, against A20 and EL4 lymphoma cells in comparison with previously used murine CpG motif (1826-CpG). To evaluate the potential cytotoxic effects of KSK-CpG on lymphoma cells, cell viability assay, confocal microscopy, flow cytometry, DNA fragmentation, Western blotting, and reverse transcription-polymerase chain reaction (RT-PCR) analysis were used. We found that KSK-CpG induced direct cytotoxicity in A20 lymphoma cells, but not in EL4 lymphoma cells, at least in part via TLR9-mediated pathways. Apoptotic cell death was demonstrated to play an important role in CpG-ODNs-induced cytotoxicity. In addition, both mitochondrial membrane potential decrease and G1-phase arrest were involved in KSK-CpG-induced apoptosis in A20 cells. The activities of apoptotic molecules such as caspase-3, PARP, and Bax were increased, but the activation of p27 Kip1 and ERK were decreased in KSK-CpG-treated A20 cells. Furthermore, autocrine IFN-γ partially contributed to apoptotic cell death in KSK-CpG-treated A20 cells. Collectively, our findings suggest that KSK-CpG induces apoptotic cell death in A20 lymphoma cells at least in part by inducing G1-phase arrest and autocrine IFN-γ via increasing TLR9 expression, without the need for immune system of tumor-bearing host. This new understanding supports the development of TLR9-targeted therapy with CpG-ODN as a direct therapeutic agent for treating B lymphoma. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mechanisms regulating plasminogen activators in transformed retinal ganglion cells

PubMed Central

Rock, Nathan; Chintala, Shravan K.

2008-01-01

Irreversible loss of retinal ganglion cells (RGCs) is a major clinical issue in glaucoma, but the mechanisms that lead to RGC death are currently unclear. We have previously reported that elevated levels of tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) cause the death of RGCs in vivo and transformed retinal ganglion cells (RGC-5) in vitro. Yet, it is unclear how secreted proteases such as tPA and uPA directly cause RGCs' death. In this study, by employing RGC-5 cells, we report that tPA and uPA elicit their direct effect through the low-density lipoprotein-related receptor-1 (LRP-1). We also show that blockade of protease-LRP-1 interaction leads to a compete reduction in autocrine synthesis of tPA and uPA, and prevents protease-mediated death of RGC-5 cells. RGC-5 cells were cultured in serum-free medium and treated with 2.0 uM Staurosporine to induce their differentiation. Neurite outgrowth was observed by a phase contrast microscope and quantified by NeuroJ imaging software. Proteolytic activities of tPA and uPA were determined by zymography assays. Cell viability was determined by MTT assays. Compared to untreated RGC-5 cells, cells treated with Staurosporine differentiated, synthesized and secreted elevated levels of tPA and uPA, and underwent cell death. In contrast, when RGC-5 cells were treated with Staurosporine along with the receptor associated protein (RAP), proteolytic activities of both tPA and uPA were significantly reduced. Under these conditions, a significant number of RGC-5 cells survived and showed increased neurite outgrowth. These results indicate that LRP-1 regulates autocrine synthesis of tPA and uPA in RGC-5 cells and suggest that the use of RAP to antagonize the effect of proteases may be a way to prevent RGC death in glaucoma. PMID:18243176

Promotion of human early embryonic development and blastocyst outgrowth in vitro using autocrine/paracrine growth factors.

PubMed

Kawamura, Kazuhiro; Chen, Yuan; Shu, Yimin; Cheng, Yuan; Qiao, Jie; Behr, Barry; Pera, Renee A Reijo; Hsueh, Aaron J W

2012-01-01

Studies using animal models demonstrated the importance of autocrine/paracrine factors secreted by preimplantation embryos and reproductive tracts for embryonic development and implantation. Although in vitro fertilization-embryo transfer (IVF-ET) is an established procedure, there is no evidence that present culture conditions are optimal for human early embryonic development. In this study, key polypeptide ligands known to be important for early embryonic development in animal models were tested for their ability to improve human early embryo development and blastocyst outgrowth in vitro. We confirmed the expression of key ligand/receptor pairs in cleavage embryos derived from discarded human tri-pronuclear zygotes and in human endometrium. Combined treatment with key embryonic growth factors (brain-derived neurotrophic factor, colony-stimulating factor, epidermal growth factor, granulocyte macrophage colony-stimulating factor, insulin-like growth factor-1, glial cell-line derived neurotrophic factor, and artemin) in serum-free media promoted >2.5-fold the development of tri-pronuclear zygotes to blastocysts. For normally fertilized embryos, day 3 surplus embryos cultured individually with the key growth factors showed >3-fold increases in the development of 6-8 cell stage embryos to blastocysts and >7-fold increase in the proportion of high quality blastocysts based on Gardner's criteria. Growth factor treatment also led to a 2-fold promotion of blastocyst outgrowth in vitro when day 7 surplus hatching blastocysts were used. When failed-to-be-fertilized oocytes were used to perform somatic cell nuclear transfer (SCNT) using fibroblasts as donor karyoplasts, inclusion of growth factors increased the progression of reconstructed SCNT embryos to >4-cell stage embryos. Growth factor supplementation of serum-free cultures could promote optimal early embryonic development and implantation in IVF-ET and SCNT procedures. This approach is valuable for infertility treatment and future derivation of patient-specific embryonic stem cells.

Loss of Ranbp2 in motoneurons causes disruption of nucleocytoplasmic and chemokine signaling, proteostasis of hnRNPH3 and Mmp28, and development of amyotrophic lateral sclerosis-like syndromes.

PubMed

Cho, Kyoung-In; Yoon, Dosuk; Qiu, Sunny; Danziger, Zachary; Grill, Warren M; Wetsel, William C; Ferreira, Paulo A

2017-05-01

The pathogenic drivers of sporadic and familial motor neuron disease (MND), such amyotrophic lateral sclerosis (ALS), are unknown. MND impairs the Ran GTPase cycle, which controls nucleocytoplasmic transport, ribostasis and proteostasis; however, cause-effect mechanisms of Ran GTPase modulators in motoneuron pathobiology have remained elusive. The cytosolic and peripheral nucleoporin Ranbp2 is a crucial regulator of the Ran GTPase cycle and of the proteostasis of neurological disease-prone substrates, but the roles of Ranbp2 in motoneuron biology and disease remain unknown. This study shows that conditional ablation of Ranbp2 in mouse Thy1 motoneurons causes ALS syndromes with hypoactivity followed by hindlimb paralysis, respiratory distress and, ultimately, death. These phenotypes are accompanied by: a decline in the nerve conduction velocity, free fatty acids and phophatidylcholine of the sciatic nerve; a reduction in the g-ratios of sciatic and phrenic nerves; and hypertrophy of motoneurons. Furthermore, Ranbp2 loss disrupts the nucleocytoplasmic partitioning of the import and export nuclear receptors importin β and exportin 1, respectively, Ran GTPase and histone deacetylase 4. Whole-transcriptome, proteomic and cellular analyses uncovered that the chemokine receptor Cxcr4, its antagonizing ligands Cxcl12 and Cxcl14, and effector, latent and activated Stat3 all undergo early autocrine and proteostatic deregulation, and intracellular sequestration and aggregation as a result of Ranbp2 loss in motoneurons. These effects were accompanied by paracrine and autocrine neuroglial deregulation of hnRNPH3 proteostasis in sciatic nerve and motoneurons, respectively, and post-transcriptional downregulation of metalloproteinase 28 in the sciatic nerve. Mechanistically, our results demonstrate that Ranbp2 controls nucleocytoplasmic, chemokine and metalloproteinase 28 signaling, and proteostasis of substrates that are crucial to motoneuronal homeostasis and whose impairments by loss of Ranbp2 drive ALS-like syndromes. © 2017. Published by The Company of Biologists Ltd.

Interleukin-8 (IL-8) over-production and autocrine cell activation are key factors in monomethylarsonous acid [MMA(III)]-induced malignant transformation of urothelial cells.

PubMed

Escudero-Lourdes, C; Wu, T; Camarillo, J M; Gandolfi, A J

2012-01-01

The association between chronic human exposure to arsenicals and bladder cancer development is well recognized; however, the underlying molecular mechanisms have not been fully determined. We propose that inflammatory responses can play a pathogenic role in arsenic-related bladder carcinogenesis. In previous studies, it was demonstrated that chronic exposure to 50 nM monomethylarsenous acid [MMA(III)] leads to malignant transformation of an immortalized model of urothelial cells (UROtsa), with only 3 mo of exposure necessary to trigger the transformation-related changes. In the three-month window of exposure, the cells over-expressed pro-inflammatory cytokines (IL-1β, IL-6 and IL-8), consistent with the sustained activation of NFKβ and AP1/c-jun, ERK2, and STAT3. IL-8 was over-expressed within hours after exposure to MMA(III), and sustained over-expression was observed during chronic exposure. In this study, we profiled IL-8 expression in UROtsa cells exposed to 50 nM MMA(III) for 1 to 5 mo. IL-8 expression was increased mainly in cells after 3 mo MMA(III) exposure, and its production was also found increased in tumors derived from these cells after heterotransplantation in SCID mice. UROtsa cells do express both receptors, CXCR1 and CXCR2, suggesting that autocrine cell activation could be important in cell transformation. Supporting this observation and consistent with IL-8 over-expression, CXCR1 internalization was significantly increased after three months of exposure to MMA(III). The expression of MMP-9, cyclin D1, bcl-2, and VGEF was significantly increased in cells exposed to MMA(III) for 3 mo, but these mitogen-activated kinases were significantly decreased after IL-8 gene silencing, together with a decrease in cell proliferation rate and in anchorage-independent colony formation. These results suggest a relevant role of IL-8 in MMA(III)-induced UROtsa cell transformation. Copyright © 2011 Elsevier Inc. All rights reserved.

Combination of glycopyrronium and indacaterol inhibits carbachol-induced ERK5 signal in fibrotic processes.

PubMed

Namba, Yukiko; Togo, Shinsaku; Tulafu, Miniwan; Kadoya, Kotaro; Nagahama, Kumi Yoneda; Taka, Hikari; Kaga, Naoko; Orimo, Akira; Liu, Xiangde; Takahashi, Kazuhisa

2017-03-11

Airway fibrosis is one of the pathological features of chronic obstructive pulmonary disease (COPD), and recent studies revealed that acetylcholine plays an important role in the development of airway remodeling by stimulating proliferation and collagen synthesis of lung fibroblasts. This study was designed to examine the effects of a long-acting muscarinic receptor antagonist (LAMA) glycopyrronium and a long-acting β2 adrenergic receptor agonist (LABA) indacaterol on acetylcholine-mediated fibrotic responses in lung fibroblasts. After carbachol (CCh) or transforming growth factor-β1 (TGF-β1) exposure, the response to glycopyrronium and indacaterol was determined in vitro in fibroblasts isolated from mild-to-moderate COPD lung tissue. The ability of fibroblasts to mediate the contraction of collagen gels was assessed. The expression of α-smooth muscle actin (α-SMA) and the phosphorylation of extracellular-signal-regulated kinase 5 (ERK5) were determined by immunoblot. TGF-β1 was quantified by ELISA and acetylcholine was quantified by liquid chromatography tandem-mass spectrometry. CCh stimulated fibroblast-mediated collagen gel contraction and α-SMA expression and TGF-β1 release by fibroblasts. Blockade of autocrine TGF-β1 attenuated CCh-mediated fibrotic responses, while TGF-β1 did not stimulate acetylcholine release. Glycopyrronium plus indacaterol significantly attenuated CCh- and TGF-β1-mediated fibrotic responses through inhibition of ERK5 phosphorylation. Notably, the magnitudes of CCh- and TGF-β1-stimulated gel contraction, CCh-induced TGF-β1 release, and ERK5 phosphorylation were greater in fibroblasts isolated from COPD subjects than in those from non-smokers. CCh induced TGF-β1 self-sustaining signaling loops by potentiating ERK5 signaling and promoted myofibroblast activity. This autocrine signaling mechanism may be an attractive therapeutic target to block the fibrotic response, which was modulated by the combination of glycopyrronium and indacaterol.

FGF7 supports hematopoietic stem and progenitor cells and niche-dependent myeloblastoma cells via autocrine action on bone marrow stromal cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishino, Ruri; Minami, Kaori; Tanaka, Satowa

2013-10-11

Highlights: •FGF7 is downregulated in MED1-deficient mesenchymal cells. •FGF7 produced by mesenchymal stromal cells is a novel hematopoietic niche molecule. •FGF7 supports hematopoietic progenitor cells and niche-dependent leukemia cells. •FGF7 activates FGFR2IIIb of bone marrow stromal cells in an autocrine manner. •FGF7 indirectly acts on hematopoietic cells lacking FGFR2IIIb via stromal cells. -- Abstract: FGF1 and FGF2 support hematopoietic stem and progenitor cells (HSPCs) under stress conditions. In this study, we show that fibroblast growth factor (FGF7) may be a novel niche factor for HSPC support and leukemic growth. FGF7 expression was attenuated in mouse embryonic fibroblasts (MEFs) deficient formore » the MED1 subunit of the Mediator transcriptional coregulator complex. When normal mouse bone marrow (BM) cells were cocultured with Med1{sup +/+} MEFs or BM stromal cells in the presence of anti-FGF7 antibody, the growth of BM cells and the number of long-time culture-initiating cells (LTC-ICs) decreased significantly. Anti-FGF7 antibody also attenuated the proliferation and cobblestone formation of MB1 stromal cell-dependent myeloblastoma cells. The addition of recombinant FGF7 to the coculture of BM cells and Med1{sup −/−} MEFs increased BM cells and LTC-ICs. FGF7 and its cognate receptor, FGFR2IIIb, were undetectable in BM cells, but MEFs and BM stromal cells expressed both. FGF7 activated downstream targets of FGFR2IIIb in Med1{sup +/+} and Med1{sup −/−} MEFs and BM stromal cells. Taken together, we propose that FGF7 supports HSPCs and leukemia-initiating cells indirectly via FGFR2IIIb expressed on stromal cells.« less

Reversion of autocrine transformation by a dominant negative platelet-derived growth factor mutant.

PubMed Central

Vassbotn, F S; Andersson, M; Westermark, B; Heldin, C H; Ostman, A

1993-01-01

A non-receptor-binding mutant of the platelet-derived growth factor (PDGF) A chain, PDGF-0, was generated by exchanging 7 amino acids in the sequence. The mutant chains formed dimers that were similar to wild-type PDGF-AA with regard to stability and rate of processing to the mature 30-kDa secreted forms. Moreover, the mutant chains formed disulfide-bonded heterodimers with the PDGF B chain in NIH 3T3 cells heterodimer underwent the same processing and secretion as PDGF-AB. Transfection of c-sis-expressing 3T3 cells with PDGF-0 significantly inhibited the transformed phenotype of these cells, as determined by the following criteria. (i) Compared with PDGF-0-negative clones, PDGF-0-producing clones showed a reverted morphology. (ii) Clones producing PDGF-0 grew more slowly than PDGF-0-negative clones, with a fivefold difference in cell number after 14 days in culture. (iii) The expression of PDGF-0 completely inhibited the ability of the c-sis-expressing 3T3 cells to form colonies in soft agar; this inhibition was overcome by the addition of recombinant PDGF-BB to the culture medium, showing that the lack of colony formation of these cells was not due to a general unresponsiveness to PDGF. The specific expression of a PDGF-0/PDGF wild-type heterodimer in COS cells revealed that the affinity of the mutant heterodimer for the PDGF alpha receptor was decreased by approximately 50-fold compared with that of PDGF-AA. Thus, we show that a non-receptor-binding PDGF A-chain mutant neutralizes in a trans-dominant manner the autocrine transforming potential of the c-sis/PDGF B chain by forming low-affinity heterodimers with wild-type PDGF chains. This method of specifically antagonizing the effect of PDGF may be useful in investigations of the role of PDGF in normal and pathological conditions. Images PMID:8321214

Reversion of autocrine transformation by a dominant negative platelet-derived growth factor mutant.

PubMed

Vassbotn, F S; Andersson, M; Westermark, B; Heldin, C H; Ostman, A

1993-07-01

A non-receptor-binding mutant of the platelet-derived growth factor (PDGF) A chain, PDGF-0, was generated by exchanging 7 amino acids in the sequence. The mutant chains formed dimers that were similar to wild-type PDGF-AA with regard to stability and rate of processing to the mature 30-kDa secreted forms. Moreover, the mutant chains formed disulfide-bonded heterodimers with the PDGF B chain in NIH 3T3 cells heterodimer underwent the same processing and secretion as PDGF-AB. Transfection of c-sis-expressing 3T3 cells with PDGF-0 significantly inhibited the transformed phenotype of these cells, as determined by the following criteria. (i) Compared with PDGF-0-negative clones, PDGF-0-producing clones showed a reverted morphology. (ii) Clones producing PDGF-0 grew more slowly than PDGF-0-negative clones, with a fivefold difference in cell number after 14 days in culture. (iii) The expression of PDGF-0 completely inhibited the ability of the c-sis-expressing 3T3 cells to form colonies in soft agar; this inhibition was overcome by the addition of recombinant PDGF-BB to the culture medium, showing that the lack of colony formation of these cells was not due to a general unresponsiveness to PDGF. The specific expression of a PDGF-0/PDGF wild-type heterodimer in COS cells revealed that the affinity of the mutant heterodimer for the PDGF alpha receptor was decreased by approximately 50-fold compared with that of PDGF-AA. Thus, we show that a non-receptor-binding PDGF A-chain mutant neutralizes in a trans-dominant manner the autocrine transforming potential of the c-sis/PDGF B chain by forming low-affinity heterodimers with wild-type PDGF chains. This method of specifically antagonizing the effect of PDGF may be useful in investigations of the role of PDGF in normal and pathological conditions.

Leucine-enkephalin-like immunoreactivity is localized in luteinizing hormone-producing cells in the axolotl (Ambystoma mexicanum) pituitary.

PubMed

Suzuki, Hirohumi; Yamamoto, Toshiharu

2014-02-01

In this study, we used immunohistochemical techniques to determine the cell type of leucine-enkephalin (Leu-ENK)-immunoreactive cells in the axolotl (Ambystoma mexicanum) pituitary. Immunoreactive cells were scattered throughout the pars distalis except for the dorso-caudal portion. These cells were immuno-positive for luteinizing hormone (LH), but they were immuno-negative for adrenocorticotrophic, growth, and thyroid-stimulating hormones, as well as prolactin. Immunoelectron microscopy demonstrated that Leu-ENK-like substance and LH co-localized within the same secretory granules. Leu-ENK secreted from gonadotrophs may participate in LH secretion in an autocrine fashion, and/or may participate in the release of sex steroids together with LH. Copyright © 2013 Elsevier Ltd. All rights reserved.

The contribution of the sympathetic nervous system to the immunopathology of experimental pulmonary tuberculosis.

PubMed

Barrios-Payán, Jorge; Revuelta, Alberto; Mata-Espinosa, Dulce; Marquina-Castillo, Brenda; Villanueva, Enrique Becerril; Gutiérrez, María Eugenia Hernández; Pérez-Sánchez, Gilberto; Pavón, Lenin; Hernandez-Pando, Rogelio

2016-09-15

The role of norepinephrine (NE) in the immunopathology of experimental tuberculosis (TB) was studied by measuring pulmonary NE and determining its cellular sources and targets. Functional studies were performed administrating adrenergic and anti-adrenergic drugs at different TB phases. Results showed high production of NE during early infection by adrenergic nerve terminals and lymphocytes located in the lungs and mediastinal lymph nodes, these cells highly expressed β2 adreno-receptors (β2AR) which by an autocrine mechanism promote Th-1 cell differentiation favoring protection. During advanced infection, the production of NE and β2AR sharply decreased, suggesting that adrenergic activity is less important during late TB. Copyright © 2016 Elsevier B.V. All rights reserved.

Exosomes as agents of change in the cardiovascular system.

PubMed

Poe, A J; Knowlton, A A

2017-10-01

Exosomes have an evolving role in paracrine and autocrine signaling, which is enhanced because these lipid vesicles are quite stable and can deliver miRNA, DNA, protein and other molecules to cells throughout the body. Most cell types release exosomes, and exosomes are found in all biological fluids, making them accessible biomarkers. Significantly, exosomes can carry a biologically potent cargo, which can alter the phenotype of recipient cells. In the cardiovascular system exosomes have been primarily studied for their role in mediating the beneficial effects of mesenchymal stem cells after myocardial injury. Exosomes released by cardiac cells in disease states, such as myocardial ischemia, can potentially have important pathophysiologic effects on other cardiac cells as well as on distant organs. Published by Elsevier Ltd.

[The extraneuronal cholinergic system of the skin. Basic facts and clinical relevance].

PubMed

Kurzen, H

2004-05-01

Acetylcholine (ACh) is a prototypical neurotransmitter that has recently been recognized to occur extraneuronally in a large variety of cells. ACh and its nicotinic and muscarinic receptors are produced in the epidermis and in the adnexal structures of the skin in a highly complicated pattern. They are also produced in melanocytes, fibroblasts, endothelial cells and immune cells. Through autocrine, paracrine and endocrine mechanisms, the cholinergic system is involved in the basic functions of the skin, such as keratinocyte differentiation, epidermal barrier formation, sweating, sebum production, blood circulation, angiogenesis and a variety of immune reactions. Hence diseases like acne vulgaris, vitiligo, psoriasis, pemphigus vulgaris and atopic dermatitis may be influenced. The exploration of the extraneuronal cholinergic system of the skin has only just begun.

microRNAs as Pharmacological Targets in Endothelial Cell Function and Dysfunction

PubMed Central

Chamorro-Jorganes, Aránzazu; Araldi, Elisa; Suárez, Yajaira

2013-01-01

Endothelial cell dysfunction is a term which implies the dysregulation of normal endothelial cell functions, including impairment of the barrier functions, control of vascular tone, disturbance of proliferative, migratory and morphogenic capacities of endothelial cells, as well as control of leukocyte trafficking. MicroRNAs (miRNAs) are short non-coding RNAs that have emerged as critical regulators of gene expression acting predominantly at the post-transcriptional level. This review summarizes the latest insights in the identification of endothelial-specific miRNAs and their targets, as well as their roles in controlling endothelial cell functions in both autocrine and paracrine manner. In addition, we discuss the therapeutic potential for the treatment of endothelial cell dysfunction and associated vascular pathophysiological conditions. PMID:23603154

Growth Hormone and Reproduction: A Review of Endocrine and Autocrine/Paracrine Interactions

PubMed Central

Hull, Kerry L.; Harvey, Steve

2014-01-01

The somatotropic axis, consisting of growth hormone (GH), hepatic insulin-like growth factor I (IGF-I), and assorted releasing factors, regulates growth and body composition. Axiomatically, since optimal body composition enhances reproductive function, general somatic actions of GH modulate reproductive function. A growing body of evidence supports the hypothesis that GH also modulates reproduction directly, exerting both gonadotropin-dependent and gonadotropin-independent actions in both males and females. Moreover, recent studies indicate GH produced within reproductive tissues differs from pituitary GH in terms of secretion and action. Accordingly, GH is increasingly used as a fertility adjunct in males and females, both humans and nonhumans. This review reconsiders reproductive actions of GH in vertebrates in respect to these new conceptual developments. PMID:25580121

The pancreatic stellate cell: a star on the rise in pancreatic diseases

PubMed Central

Omary, M. Bishr; Lugea, Aurelia; Lowe, Anson W.; Pandol, Stephen J.

2007-01-01

Pancreatic stellate cells (PaSCs) are myofibroblast-like cells found in the areas of the pancreas that have exocrine function. PaSCs are regulated by autocrine and paracrine stimuli and share many features with their hepatic counterparts, studies of which have helped further our understanding of PaSC biology. Activation of PaSCs induces them to proliferate, to migrate to sites of tissue damage, to contract and possibly phagocytose, and to synthesize ECM components to promote tissue repair. Sustained activation of PaSCs has an increasingly appreciated role in the fibrosis that is associated with chronic pancreatitis and with pancreatic cancer. Therefore, understanding the biology of PaSCs offers potential therapeutic targets for the treatment and prevention of these diseases. PMID:17200706

Endothelial cell motility, coordination and pattern formation during vasculogenesis.

PubMed

Czirok, Andras

2013-01-01

How vascular networks assemble is a fundamental problem of developmental biology that also has medical importance. To explain the organizational principles behind vascular patterning, we must understand how can tissue level structures be controlled through cell behavior patterns like motility and adhesion that, in turn, are determined by biochemical signal transduction processes? We discuss the various ideas that have been proposed as mechanisms for vascular network assembly: cell motility guided by extracellular matrix alignment (contact guidance), chemotaxis guided by paracrine and autocrine morphogens, and multicellular sprouting guided by cell-cell contacts. All of these processes yield emergent patterns, thus endothelial cells can form an interconnected structure autonomously, without guidance from an external pre-pattern. © 2013 Wiley Periodicals, Inc.

The perinatal implications of angiogenic factors.

PubMed

Smith, Gordon C S; Wear, Helen

2009-04-01

To summarize recent findings relating maternal circulating levels of proteins associated with angiogenesis and the outcome of pregnancy. In preeclampsia, levels of placental growth factor (PlGF) become abnormal prior to soluble fms-like tyrosine kinase 1 (sFlt-1). Longitudinal measurement of changes in protein level are better predictors of disease than measurement at a single time point in pregnancy and also appear to be more strongly associated with early-onset disease. The levels of angiogenic proteins provide additional predictive information over abnormal uteroplacental Doppler. The preeclampsia-like phenotype of rats overexpressing sFlt-1 can be ameliorated by administration of a protein which binds and inactivates sFlt-1. Animal models demonstrate that uteroplacental ischemia leads to elevated maternal serum levels of sFlt-1 and decreased PlGF. Similarly, studies of human trophoblast cells demonstrate that hypoxia stimulates release of sFlt-1. Autocrine vascular endothelial growth factor (VEGF) has a trophic effect on the endothelium, distinct from its control of angiogenesis. By blocking this effect, elevated sFlt-1 could lead to systemic endothelial cell dysfunction, one of the key features of preeclampsia. Low levels of PlGF are associated with intrauterine growth restriction. However, in the first trimester of pregnancy, high levels of sFlt-1 were associated with reduced rates of growth restriction, preterm birth and stillbirth. Regulators of the VEGF system may have a causal role in the sequence of events leading to preeclampsia and may be targets for novel therapies. However, better knowledge of the biology is required prior to clinical trials of interventions.

Temporal-logic analysis of microglial phenotypic conversion with exposure to amyloid-β.

PubMed

Anastasio, Thomas J

2015-02-01

Alzheimer Disease (AD) remains a leading killer with no adequate treatment. Ongoing research increasingly implicates the brain's immune system as a critical contributor to AD pathogenesis, but the complexity of the immune contribution poses a barrier to understanding. Here I use temporal logic to analyze a computational specification of the immune component of AD. Temporal logic is an extension of logic to propositions expressed in terms of time. It has traditionally been used to analyze computational specifications of complex engineered systems but applications to complex biological systems are now appearing. The inflammatory component of AD involves the responses of microglia to the peptide amyloid-β (Aβ), which is an inflammatory stimulus and a likely causative AD agent. Temporal-logic analysis of the model provides explanations for the puzzling findings that Aβ induces an anti-inflammatory and well as a pro-inflammatory response, and that Aβ is phagocytized by microglia in young but not in old animals. To potentially explain the first puzzle, the model suggests that interferon-γ acts as an "autocrine bridge" over which an Aβ-induced increase in pro-inflammatory cytokines leads to an increase in anti-inflammatory mediators also. To potentially explain the second puzzle, the model identifies a potential instability in signaling via insulin-like growth factor 1 that could explain the failure of old microglia to phagocytize Aβ. The model predicts that augmentation of insulin-like growth factor 1 signaling, and activation of protein kinase C in particular, could move old microglia from a neurotoxic back toward a more neuroprotective and phagocytic phenotype.

Proteomic analysis of knock-down HLA-G in invasion of human trophoblast cell line JEG-3

PubMed Central

Liu, Haiyan; Liu, Xueyuan; Jin, Hong; Yang, Fengying; Gu, Weirong; Li, Xiaotian

2013-01-01

Previous studies showed that aberrant HLA-G expression in trophoblast cells plays important roles in trophoblast invasion; however, the mechanisms remain to be explored. In this study, we found that suppressed HLA-G expression could dramatically decrease the mRNA and protein expression levels of matrix metalloproteinase 2 and matrix metalloproteinase 9, and in the proteome assay, there were 3 identified proteins namely, prefoldin 1, eukaryotic translation elongation factor 2 and malate dehydrogenase 2, which were verified by Western blot and known to be associated with invasion, cell cycle and cell metabolism, respectively. Collectively, our study indicated a potential involvement of HLA-G in autocrine networks that may regulate prefoldin, MMPs and trophoblast invasion at the maternal-fetal interface in human pregnancy. PMID:24228107

Redox-mediated regulation of connexin proteins; focus on nitric oxide.

PubMed

García, Isaac E; Sánchez, Helmuth A; Martínez, Agustín D; Retamal, Mauricio A

2018-01-01

Connexins are membrane proteins that form hemichannels and gap junction channels at the plasma membrane. Through these channels connexins participate in autocrine and paracrine intercellular communication. Connexin-based channels are tightly regulated by membrane potential, phosphorylation, pH, redox potential, and divalent cations, among others, and the imbalance of this regulation have been linked to many acquired and genetic diseases. Concerning the redox potential regulation, the nitric oxide (NO) has been described as a modulator of the hemichannels and gap junction channels properties. However, how NO regulates these channels is not well understood. In this mini-review, we summarize the current knowledge about the effects of redox potential focused in NO on the trafficking, formation and functional properties of hemichannels and gap junction channels. Copyright © 2017 Elsevier B.V. All rights reserved.

The unique endocrine milieu of the fetus.

PubMed Central

Fisher, D A

1986-01-01

Table II summarizes in tabular form the major features of the fetal endocrine milieu discussed in the foregoing pages. The mammalian fetus develops in an environment where respiration, alimentation, and excretory functions are provided by the placenta. Fetal tissue metabolism is oriented largely to anabolism; body temperature is modulated by maternal metabolism, and fetal tissue thermogenesis is maintained at a basal level. Tissue and organ growth appear to be regulated by growth factors which probably function by autocrine or paracrine mechanisms during most of gestation (72, 146-148). In this milieu conventional endocrine control systems are largely redundant, and other transient systems more appropriate to the intrauterine environment have evolved. We have developed some insights into these systems, but much more information is necessary before we can truly understand this fascinating environment. PMID:3018041

PGE2 released by primary sensory neurons modulates Toll-like receptor 4 activities through an EP4 receptor-dependent process.

PubMed

Tse, Kai-Hei; Chow, Kevin B S; Wise, Helen

2016-04-15

Exogenous prostaglandin E2 (PGE2) displays mixed regulatory properties with regard to inflammatory gene expression in dorsal root ganglion (DRG) cells. We show here that endogenously-produced nanomolar concentrations of PGE2, such as that generated in response to Toll-like receptor 4 (TLR4) stimulation, inhibits both cyclooxygenase-2 (COX-2) and tumour necrosis factor alpha (TNFα) mRNA expression in DRG cells in an EP4 receptor-dependent manner. DRG neurons appear to be the major source of PGE2 in the DRG and likely serve as both an autocrine and paracrine system for limiting over-activation of both DRG neurons and glial cells in response to TLR4 stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Next-Generation Connexin and Pannexin Cell Biology.

PubMed

Esseltine, Jessica L; Laird, Dale W

2016-12-01

Connexins and pannexins are two families of large-pore channel forming proteins that are capable of passing small signaling molecules. While connexins serve the seminal task of direct gap junctional intercellular communication, pannexins are far less understood but function primarily as single membrane channels in autocrine and paracrine signaling. Advancements in connexin and pannexin biology in recent years has revealed that in addition to well-described classical functions at the plasma membrane, exciting new evidence suggests that connexins and pannexins participate in alternative pathways involving multiple intracellular compartments. Here we briefly highlight classical functions of connexins and pannexins but focus our attention mostly on the transformative findings that suggest that these channel-forming proteins may serve roles far beyond our current understandings. Copyright © 2016 Elsevier Ltd. All rights reserved.

CELLULAR CONTROL OF CONNECTIVE TISSUE MATRIX TENSION†

PubMed Central

Langevin, Helene M.; Nedergaard, Maiken; Howe, Alan

2013-01-01

The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function and cancer. PMID:23444198

Expression of CXCR7 chemokine receptor in human meningioma cells and in intratumoral microvasculature.

PubMed

Würth, Roberto; Barbieri, Federica; Bajetto, Adriana; Pattarozzi, Alessandra; Gatti, Monica; Porcile, Carola; Zona, Gianluigi; Ravetti, Jean-Louis; Spaziante, Renato; Florio, Tullio

2011-05-01

CXCR4 and CXCR7 chemokine receptors, and their ligands CXCL11 and CXCL12, have been often involved in tumor cell proliferation and survival. We report the expression pattern of these ligand/receptor pairs in 22 human meningiomas. High CXCR7 and CXCL12 expression was associated with high-proliferative tumors. CXCR7 levels were correlated to the content of both ligands, suggesting a possible autocrine regulation. CXCR4 and CXCL12 were homogeneously expressed within tumor cells, while CXCR7 was mainly detected in tumor endothelial cells and CXCL11 in pericytes. Our results highlight the preferential CXCR7 and CXCL12 expression within more aggressive tumors and the possible role of CXCR7 in meningioma vascularization. Copyright © 2011 Elsevier B.V. All rights reserved.

Role of B61, the Ligand for the Eck Receptor Tyrosine Kinase, in TNF- α-Induced Angiogenesis

NASA Astrophysics Data System (ADS)

Pandey, Akhilesh; Shao, Haining; Marks, Rory M.; Polverini, Peter J.; Dixit, Vishva M.

1995-04-01

B61, a cytokine-inducible endothelial gene product, is the ligand for the Eck receptor protein tyrosine kinase (RPTK). Expression of a B61-immunoglobulin chimera showed that B61 could act as an angiogenic factor in vivo and a chemoattractant for endothelial cells in vitro. The Eck RPTK was activated by tumor necrosis factor-α (TNF-α) through induction of B61, and an antibody to B61 attenuated angiogenesis induced by TNF-α but not by basic fibroblast growth factor. This finding suggests the existence of an autocrine or paracrine loop involving activation of the Eck RPTK by its inducible ligand B61 after an inflammatory stimulus, the net effect of which would be to promote angiogenesis, a hallmark of chronic inflammation.

Role of B61, the ligand for the Eck receptor tyrosine kinase, in TNF-alpha-induced angiogenesis.

PubMed

Pandey, A; Shao, H; Marks, R M; Polverini, P J; Dixit, V M

1995-04-28

B61, a cytokine-inducible endothelial gene product, is the ligand for the Eck receptor protein tyrosine kinase (RPTK). Expression of a B61-immunoglobulin chimera showed that B61 could act as an angiogenic factor in vivo and a chemoattractant for endothelial cells in vitro. The Eck RPTK was activated by tumor necrosis factor-alpha (TNF-alpha) through induction of B61, and an antibody to B61 attenuated angiogenesis induced by TNF-alpha but not by basic fibroblast growth factor. This finding suggests the existence of an autocrine or paracrine loop involving activation of the Eck RPTK by its inducible ligand B61 after an inflammatory stimulus, the net effect of which would be to promote angiogenesis, a hallmark of chronic inflammation.

Tumor-associated mesenchymal stem-like cells provide extracellular signaling cue for invasiveness of glioblastoma cells

PubMed Central

Yoo, Ki-Chun; Lee, Ji-Hyun; Kim, In-Gyu; Kim, Min-Jung; Chang, Jong Hee; Kang, Seok-Gu; Lee, Su-Jae

2017-01-01

Hyaluronic acid (HA) is abundant in tumor microenvironment and closely associated with invasiveness of glioblastoma (GBM) cells. However, the cellular mechanism underlying HA-rich microenvironment in GBM remains unexplored. Here, we show that tumor-associated mesenchymal stem-like cells (tMSLCs) contribute to abundance of hyaluronic acid (HA) in tumor microenvironment through HA synthase-2 (HAS2) induction, and thereby enhances invasiveness of GBM cells. In an autocrine manner, C5a secreted by tMSLCs activated ERK MAPK for HAS2 induction in tMSLCs. Importantly, HA acted as a signaling ligand of its cognate receptor RHAMM for intracellular signaling activation underlying invasiveness of GBM cells. Taken together, our study suggests that tMSLCs contribute to HA-rich proinvasive ECM microenvironment in GBM. PMID:27903965

Role of obestatin on growth hormone secretion: An in vitro approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pazos, Yolanda, E-mail: yolanda.pazos@usc.es; CIBER Fisiopatologia de la Obesidad y Nutricion; Alvarez, Carlos J.P.

Obestatin, the ghrelin-associated peptide, showed to activate MAPK signaling with no effect on Akt nor cell proliferating activity in rat tumor somatotroph cells (growth cells, GC). A sequential analysis of the obestatin transmembrane signaling pathway indicated a route involving the consecutive activation of G{sub i}, PI3k, novel PKC{epsilon}, and Src for ERK1/2 activation. Furthermore, obestatin treatment triggers growth hormone (GH) release in the first 30 min, being more acute at 15 min. At 1 h, obestatin treated cells showed the same levels in GH secretion than controls. Added to this functionality, obestatin was secreted by GC cells. Based on themore » capacity to stimulate GH release from somatotroph cells, obestatin may act directly in the pituitary through an autocrine/paracrine mechanism.« less

Signal integration: a framework for understanding the efficacy of therapeutics targeting the human EGFR family

PubMed Central

Shepard, H. Michael; Brdlik, Cathleen M.; Schreiber, Hans

2008-01-01

The human EGFR (HER) family is essential for communication between many epithelial cancer cell types and the tumor microenvironment. Therapeutics targeting the HER family have demonstrated clinical success in the treatment of diverse epithelial cancers. Here we propose that the success of HER family–targeted monoclonal antibodies in cancer results from their ability to interfere with HER family consolidation of signals initiated by a multitude of other receptor systems. Ligand/receptor systems that initiate these signals include cytokine receptors, chemokine receptors, TLRs, GPCRs, and integrins. We further extrapolate that improvements in cancer therapeutics targeting the HER family are likely to incorporate mechanisms that block or reverse stromal support of malignant progression by isolating the HER family from autocrine and stromal influences. PMID:18982164

Involvement of a Gardos-type potassium channel in head activator-induced mitosis of BON cells.

PubMed

Kayser, S T; Ulrich, H; Schaller, H C

1998-06-01

The human neuroendocrine cell line BON was used to study second messengers involved in signal transduction for entry into mitosis. BON cells produce the neuropeptide head activator (HA) and use it as autocrine growth factor. HA stimulates BON cell proliferation by triggering entry into mitosis. HA-induced mitosis is mediated by an inhibitory G protein, the action of which is blocked by pertussis toxin. HA signaling requires inhibition of the cAMP pathway, calcium influx, and hyperpolarization of cells. The latter is a very important and sensitive step involving a calcium-activated potassium channel. Cell cycle progression and proliferation of BON cells are most efficiently inhibited with specific inhibitors of this potassium channel. Pharmacology and RNA analysis suggest identity with the recently cloned Gardos-type potassium channel.

Cell-derived microparticles: new targets in the therapeutic management of disease.

PubMed

Roseblade, Ariane; Luk, Frederick; Rawling, Tristan; Ung, Alison; Grau, Georges E R; Bebawy, Mary

2013-01-01

Intercellular communication is essential to maintain vital physiological activities and to regulate the organism's phenotype. There are a number of ways in which cells communicate with one another. This can occur via autocrine signaling, endocrine signaling or by the transfer of molecular mediators across gap junctions. More recently communication via microvesicular shedding has gained important recognition as a significant pathway by which cells can coordinate the spread and dominance of selective traits within a population. Through this communication apparatus, cells can now acquire and secure a survival advantage, particularly in the context of malignant disease. This review aims to highlight some of the functions and implications of microparticles in physiology of various disease states, and present a novel therapeutic strategy through the regulation of microparticle production.

Presynaptic miniature GABAergic currents in developing interneurons.

PubMed

Trigo, Federico F; Bouhours, Brice; Rostaing, Philippe; Papageorgiou, George; Corrie, John E T; Triller, Antoine; Ogden, David; Marty, Alain

2010-04-29

Miniature synaptic currents have long been known to represent random transmitter release under resting conditions, but much remains to be learned about their nature and function in central synapses. In this work, we describe a new class of miniature currents ("preminis") that arise by the autocrine activation of axonal receptors following random vesicular release. Preminis are prominent in gabaergic synapses made by cerebellar interneurons during the development of the molecular layer. Unlike ordinary miniature postsynaptic currents in the same cells, premini frequencies are strongly enhanced by subthreshold depolarization, suggesting that the membrane depolarization they produce belongs to a feedback loop regulating neurotransmitter release. Thus, preminis could guide the formation of the interneuron network by enhancing neurotransmitter release at recently formed synaptic contacts. Copyright 2010 Elsevier Inc. All rights reserved.

Aberrant, ectopic expression of VEGF and VEGF receptors 1 and 2 in malignant colonic epithelial cells. Implications for these cells growth via an autocrine mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahluwalia, Amrita; Jones, Michael K.; Department of Medicine, University of California, Irvine, CA

2013-08-09

Highlights: •Malignant colonic epithelial cells express VEGF and its receptors. •Cultured colon cancer cells secrete VEGF into the medium. •Inhibition of VEGF receptor significantly decreases colon cancer cell proliferation. •VEGF is critical for colon cancer cell growth. -- Abstract: Vascular endothelial growth factor A (referred to as VEGF) is implicated in colon cancer growth. Currently, the main accepted mechanism by which VEGF promotes colon cancer growth is via the stimulation of angiogenesis, which was originally postulated by late Judah Folkman. However, the cellular source of VEGF in colon cancer tissue; and, the expression of VEGF and its receptors VEGF-R1 andmore » VEGF-R2 in colon cancer cells are not fully known and are subjects of controversy. Material and methods: We examined and quantified expression of VEGF, VEGF-R1 and VEGF-R2 in three different human colonic tissue arrays containing sections of adenocarcinoma (n = 43) and normal mucosa (n = 41). In human colon cancer cell lines HCT116 and HT29 and normal colon cell lines NCM356 and NCM460, we examined expression of VEGF, VEGF-R1 and VEGF-R2 mRNA and protein, VEGF production and secretion into the culture medium; and, the effect of a potent, selective inhibitor of VEGF receptors, AL-993, on cell proliferation. Results: Human colorectal cancer specimens had strong expression of VEGF in cancer cells and also expressed VEGF-R1 and VEGF-R2.In vitro studies showed that human colon cancer cell lines, HCT116 and HT29, but not normal colonic cell lines, express VEGF, VEGF-R1 and VEGF-R2 and secrete VEGF into the medium up to a concentration 2000 pg/ml within 48 h. Furthermore, we showed that inhibition of VEGF receptors using a specific VEGF-R inhibitor significantly reduced proliferation (by >50%) of cultured colon cancer cell lines. Conclusions: Our findings support the contention that VEGF generated by colon cancer cells stimulates their growth directly through an autocrine mechanism that is independent of its primary function in the induction of angiogenesis.« less

Autocrine hemokinin-1 functions as endogenous adjuvant for IgE-mediated mast cell inflammatory responses

PubMed Central

Sumpter, Tina L.; Ho, Chin H.; Pleet, Anna R.; Tkacheva, Olga A.; Shufesky, William J.; Rojas-Canales, Darling M.; Morelli, Adrian E.; Larregina, Adriana T.

2014-01-01

Background Efficient development of atopic diseases requires interaction between allergen and adjuvant to initiate and amplify underlying inflammatory responses. Substance P (SP) and hemokinin-1 (HK-1) are neuropeptides that signal via the neurokinin-1 receptor (NK1R) to promote inflammation. Mast cells initiate the symptoms and tissue effects of atopic disorders, secreting TNF and IL-6 following FcεRI crosslinking by Ag-IgE complexes, (FcεRI-MCs). Additionally, MCs express the NK1R suggesting an adjuvant role of NK1R agonists for FcεRI-MC mediated pathologies, however in depth research addressing this relevant aspect of MC biology is lacking. Objective To investigate the effect of NK1R-signaling and the individual roles of SP and HK-1 as potential adjuvants for FcεRI-MC mediated allergic disorders. Methods Bone marrow (BM) MCs derived from C57BL/6-wild type (WT) or NK1R−/− mice were used to investigate the effects of NK1R signaling of FcεRI-activated MCs. BMMCs generated from Tac1−/− mice or following culture with Tac4 siRNA were used to address the adjuvancy of SP and HK-1. WT, NK1R−/− and c-KitW-sh/W-sh mice reconstituted with WT or NK1R−/− BMMCs were utilized to evaluate NK1R signaling on FcεRI-MC-mediated passive local and systemic anaphylaxis and airway inflammation. Results FcεRI-activated MCs up-regulated NK1R and HK-1 transcripts and protein synthesis, without modifying SP. In a positive signaling loop, HK-1 promoted TNF and IL6 secretion by MC degranulation and protein synthesis the later via the PI3K/Akt/NFκB pathways. In vivo, NK1R signaling was necessary for development of passive local and systemic anaphylaxis and chronic airway inflammation. Conclusions FcεRI-stimulation of MCs promotes autocrine secretion of HK-1 which signals via NK1R to provide adjuvancy for efficient development of FcεRI-MC-mediated disorders. PMID:25201259

Ableson Kinases Negatively Regulate Invadopodia Function and Invasion in Head and Neck Squamous Cell Carcinoma by Inhibiting an HB-EGF Autocrine Loop

PubMed Central

Hayes, Karen E.; Walk, Elyse L.; Ammer, Amanda Gatesman; Kelley, Laura C.; Martin, Karen H.; Weed, Scott A.

2014-01-01

Head and neck squamous cell carcinoma (HNSCC) has a proclivity for locoregional invasion. HNSCC mediates invasion in part through invadopodia-based proteolysis of the extracellular matrix (ECM). Activation of Src, Erk1/2, Abl and Arg downstream of epidermal growth factor receptor (EGFR) modulates invadopodia activity through phosphorylation of the actin regulatory protein cortactin. In MDA-MB-231 breast cancer cells, Abl and Arg function downstream of Src to phosphorylate cortactin, promoting invadopodia ECM degradation activity and thus assigning a pro-invasive role for Ableson kinases. We report that Abl kinases have an opposite, negative regulatory role in HNSCC where they suppress invadopodia and tumor invasion. Impairment of Abl expression or Abl kinase activity with imatinib mesylate enhanced HNSCC matrix degradation and 3D collagen invasion, functions that were impaired in MDA-MB-231. HNSCC lines with elevated EGFR and Src activation did not contain increased Abl or Arg kinase activity, suggesting Src could bypass Abl/Arg to phosphorylate cortactin and promote invadopodia ECM degradation. Src transformed Abl−/−/Arg−/− fibroblasts produced ECM degrading invadopodia containing pY421 cortactin, indicating that Abl/Arg are dispensable for invadopodia function in this system. Imatinib treated HNSCC cells had increased EGFR, Erk1/2 and Src activation, enhancing cortactin pY421 and pS405/418 required for invadopodia function. Imatinib stimulated shedding of the EGFR ligand heparin-binding EGF-like growth factor (HB-EGF) from HNSCC cells, where soluble HB-EGF enhanced invadopodia ECM degradation in HNSCC but not in MDA-MB-231. HNSCC cells treated with inhibitors of the EGFR invadopodia pathway indicated that EGFR and Src are required for invadopodia function. Collectively our results indicate that Abl kinases negatively regulate HNSCC invasive processes through suppression of an HB-EGF autocrine loop responsible for activating a EGFR-Src-cortactin cascade, in contrast to the invasion promoting functions of Abl kinases in breast and other cancer types. Our results provide mechanistic support for recent failed HNSCC clinical trials utilizing imatinib. PMID:23146907

Function of actin cytoskeleton in gravisensing during spaceflight

NASA Astrophysics Data System (ADS)

Hughes-Fulford, M.

Since astronauts and cosmonauts have significant bone loss in microgravity, we hypothesized that there would be physiological changes in cellular bone growth in the absence of gravity. Our first experiments on STS-56 demonstrated that quiescent osteoblasts activated by sera under microgravity conditions had a significant 60% reduction in growth (p<0.001) and a paradoxical 2 fold increase in release of autocrine PGE2 when compared to ground controls. In addition, there was a significant collapse of the actin cytoskeleton and loss of focal adhesions after 4 days of growth in microgravity. Other investigators have made similar observations of cytoskeletal modifications in microgravity. Later studies in Biorack on STS-76, 81 and 84 confirmed the increased release of PGE2 and collapse of the cytoskeleton in cells grown in microgravity conditions, however flown cells under 1g conditions maintained normal actin cytoskeleton and fibronectin matrix. We do not think that the changes seen in the cytoskeleton are due to alterations in fibronectin message or protein synthesis since no differences were found between microgravity, 1g or ground conditions. The nuclear structure was noticeably different in the flown 0g cells with elongation of the nucleus after 24 hours of microgravity, this alteration in nuclear structure was not seen in the 1g flown or ground control cells. Further examination of total RNA in the cells showed no significant changes between the three gravity conditions suggesting specific not general physiological changes in microgravity. When osteoblast mRNA was analyzed, the immediate early genes, c-myc and cox-2 and the autocrine growth factor FGFb were down-regulated in microgravity. The inability of the 0g grown osteoblast to respond to sera activation suggests that there is a major alteration in anabolic signal transduction under microgravity conditions, most probably through the growth factor receptors and/or the associated kinase pathways. It is still unclear whether these changes in signal transduction are related to the alterations in the cytoskeleton under microgravity conditions and this possibility is under study.

Expression and localization of insulin-like growth factor system in corpus luteum during different stages of estrous cycle in water buffaloes (Bubalus bubalis) and the effect of insulin-like growth factor I on production of vascular endothelial growth factor and progesterone in luteal cells cultured in vitro.

PubMed

Uniyal, S; Panda, R P; Chouhan, V S; Yadav, V P; Hyder, I; Dangi, S S; Gupta, M; Khan, F A; Sharma, G T; Bag, S; Sarkar, M

2015-01-01

This study investigated the expression and localization of insulin-like growth factor (IGF) system at different stages of buffalo CL and the role of IGF-I in stimulating vascular endothelial growth factor (VEGF) and progesterone (P4) production in cultured luteal cells. The mRNA expression of IGF system, VEGF, steroidogenic acute regulatory protein, P450scc, and hydroxysteroid dehydrogenase (HSD) was investigated by quantitative real-time polymerase chain reaction (PCR). Protein expression of IGF was demonstrated by Western blot and localization by immunohistochemistry. Progesterone and VEGF production was assayed using RIA and ELISA. A relatively high mRNA expression of IGF-I and IGF-II in early, mid- and late luteal phases with immunoreactivity mostly restricted to cytoplasm of large luteal cells indicates their autocrine role, whereas very weak immunoreactivity in endothelial cells during the mid-luteal phase indicates their paracrine role. Insulin-like growth factor receptors, IGF-IR and IGF-IIR, were restricted to large luteal cells with high mRNA and protein expressions in the mid-luteal phase. The significantly higher expression of insulin-like growth factor binding protein (IGFBP)-1, -3, -5, and -6 in the early or mid-luteal phase suggested their stimulatory role, whereas that of IGFBP-2 and -4 in mid-, late, and regressive luteal stages implied their inhibitory role. The mRNA expressions of key steroidogenic factors and VEGF were significantly higher (P < 0.05) when the culture medium was supplemented with 100 ng/mL of IGF-I for 72 hours. Moreover, IGF-I at a dose of 100 ng/mL increased P4 and VEGF production (P < 0.05). It can be concluded that IGF family members via their autocrine and paracrine effect play significant roles in promoting angiogenesis through the production of VEGF in luteal cells and steroid synthesis through the production of key steroidogenic factors. Copyright © 2015 Elsevier Inc. All rights reserved.

Up-regulation of the fibroblast growth factor 8 subfamily in human hepatocellular carcinoma for cell survival and neoangiogenesis.

PubMed

Gauglhofer, Christine; Sagmeister, Sandra; Schrottmaier, Waltraud; Fischer, Carina; Rodgarkia-Dara, Chantal; Mohr, Thomas; Stättner, Stefan; Bichler, Christoph; Kandioler, Daniela; Wrba, Fritz; Schulte-Hermann, Rolf; Holzmann, Klaus; Grusch, Michael; Marian, Brigitte; Berger, Walter; Grasl-Kraupp, Bettina

2011-03-01

Fibroblast growth factors (FGFs) and their high-affinity receptors [fibroblast growth factor receptors (FGFRs)] contribute to autocrine and paracrine growth stimulation in several non-liver cancer entities. Here we report that at least one member of the FGF8 subfamily (FGF8, FGF17, and FGF18) was up-regulated in 59% of 34 human hepatocellular carcinoma (HCC) samples that we investigated. The levels of the corresponding receptors (FGFR2, FGFR3, and FGFR4) were also elevated in the great majority of the HCC cases. Overall, 82% of the HCC cases showed overexpression of at least one FGF and/or FGFR. The functional implications of the deregulated FGF/FGFR system were investigated by the simulation of an insufficient blood supply. When HCC-1.2, HepG2, or Hep3B cells were subjected to serum withdrawal or the hypoxia-mimetic drug deferoxamine mesylate, the expression of FGF8 subfamily members increased dramatically. In the serum-starved cells, the incidence of apoptosis was elevated, whereas the addition of FGF8, FGF17, or FGF18 impaired apoptosis, which was associated with phosphorylation of extracellular signal-regulated kinase 1/2 and ribosomal protein S6. In contrast, down-modulation of FGF18 by small interfering RNA (siRNA) significantly reduced the viability of the hepatocarcinoma cells. siRNA targeting FGF18 also impaired the cells' potential to form clones at a low cell density or in soft agar. With respect to the tumor microenvironment, FGF17 and FGF18 stimulated the growth of HCC-derived myofibroblasts, and FGF8, FGF17, and FGF18 induced the proliferation and tube formation of hepatic endothelial cells. FGF8, FGF17, and FGF18 are involved in autocrine and paracrine signaling in HCC and enhance the survival of tumor cells under stress conditions, malignant behavior, and neoangiogenesis. Thus, the FGF8 subfamily supports the development and progression of hepatocellular malignancy. Copyright © 2010 American Association for the Study of Liver Diseases.

Chronic lymphocytic leukemia.

PubMed

Kay, Neil E; Hamblin, Terry J; Jelinek, Diane F; Dewald, Gordon W; Byrd, John C; Farag, Sherif; Lucas, Margaret; Lin, Thomas

2002-01-01

This update of early stage B-cell chronic lymphocytic leukemia (B-CLL) embraces current information on the diagnosis, biology, and intervention required to more fully develop algorithms for management of this disease. Emphasis on early stage is based on the rapid advancement in our understanding of the disease parameters and our increasing ability to predict for a given early stage patient whether there is a need for more aggressive management. In Section I, Dr. Terry Hamblin addresses the nature of the disease, accurate diagnostic procedures, evidence for an early "preclinical" phase, the use of newer prognostic features to distinguish who will be likely to progress or not, and whether it is best to watch or treat early stage disease. In Section II, Dr. Neil Kay and colleagues address the biologic aspects of the disease and how they may relate to disease progression. Review of the newer insights into gene expression, recurring genetic defects, role of cytokines/autocrine pathways, and the interaction of the CLL B cell with the microenvironment are emphasized. The relationship of these events to both trigger disease progression and as opportunities for future therapeutic intervention even in early stage disease is also considered. In Section III, Dr. John Byrd and colleagues review the historical and now current approaches to management of the previously untreated progressive B-CLL patient. They discuss what decision tree could be used in the initial decision to treat a given patient. The use of single agents versus newer combination approaches such as chemoimmunotherapy are discussed here. In addition, the place of marrow transplant and some of the newer antibodies available for treatment of B-CLL are considered. Finally, a challenge to utilize our growing knowledge of the biology of B-CLL in the early stage B-CLL is proffered.

Endothelial dysfunction in metabolic diseases: role of oxidation and possible therapeutic employment of N-acetylcysteine.

PubMed

Masha, A; Martina, V

2014-01-01

Several metabolic diseases present a high cardiovascular mortality due to endothelial dysfunction consequences. In the last years of the past century, it has come to light that the endothelial cells, previously considered as inert in what regards an eventual secretion activity, play a pivotal role in regulating different aspects of the vascular function (endothelial function). It was clearly demonstrated that the endothelium acts as a real active organ, owning endocrine, paracrine and autocrine modulation activities by means of which it is able to regulate the vascular homeostasis. The present review will investigate the relationship between some metabolic diseases and the endothelial dysfunction and in particular the mechanisms underlying the effects of metabolic pathologies on the endothelium. Furthermore, it will consider the possible therapeutic employment of the N-acetilcysteine in such conditions.

Cellular control of connective tissue matrix tension.

PubMed

Langevin, Helene M; Nedergaard, Maiken; Howe, Alan K

2013-08-01

The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function, and cancer. Copyright © 2013 Wiley Periodicals, Inc.

Signalling molecules in the urothelium.

PubMed

Winder, Michael; Tobin, Gunnar; Zupančič, Daša; Romih, Rok

2014-01-01

The urothelium was long considered to be a silent barrier protecting the body from the toxic effects of urine. However, today a number of dynamic abilities of the urothelium are well recognized, including its ability to act as a sensor of the intravesical environment. During recent years several pathways of these urothelial abilities have been proposed and a major part of these pathways includes release of signalling molecules. It is now evident that the urothelium represents only one part of the sensory web. Urinary bladder signalling is finely tuned machinery of signalling molecules, acting in autocrine and paracrine manner, and their receptors are specifically distributed among different types of cells in the urinary bladder. In the present review the current knowledge of the formation, release, and signalling effects of urothelial acetylcholine, ATP, adenosine, and nitric oxide in health and disease is discussed.

Aging, Atherosclerosis, and IGF-1

PubMed Central

Higashi, Yusuke; Sukhanov, Sergiy; Anwar, Asif; Shai, Shaw-Yung

2012-01-01

Insulin-like growth factor 1 (IGF-1) is an endocrine and autocrine/paracrine growth factor that circulates at high levels in the plasma and is expressed in most cell types. IGF-1 has major effects on development, cell growth and differentiation, and tissue repair. Recent evidence indicates that IGF-1 reduces atherosclerosis burden and improves features of atherosclerotic plaque stability in animal models. Potential mechanisms for this atheroprotective effect include IGF-1–induced reduction in oxidative stress, cell apoptosis, proinflammatory signaling, and endothelial dysfunction. Aging is associated with increased vascular oxidative stress and vascular disease, suggesting that IGF-1 may exert salutary effects on vascular aging processes. In this review, we will provide a comprehensive update on IGF-1's ability to modulate vascular oxidative stress and to limit atherogenesis and the vascular complications of aging. PMID:22491965

Signalling Molecules in the Urothelium

PubMed Central

Winder, Michael; Tobin, Gunnar; Zupančič, Daša; Romih, Rok

2014-01-01

The urothelium was long considered to be a silent barrier protecting the body from the toxic effects of urine. However, today a number of dynamic abilities of the urothelium are well recognized, including its ability to act as a sensor of the intravesical environment. During recent years several pathways of these urothelial abilities have been proposed and a major part of these pathways includes release of signalling molecules. It is now evident that the urothelium represents only one part of the sensory web. Urinary bladder signalling is finely tuned machinery of signalling molecules, acting in autocrine and paracrine manner, and their receptors are specifically distributed among different types of cells in the urinary bladder. In the present review the current knowledge of the formation, release, and signalling effects of urothelial acetylcholine, ATP, adenosine, and nitric oxide in health and disease is discussed. PMID:25177686

Molecular Interaction of Bone Marrow Adipose Tissue with Energy Metabolism.

PubMed

Suchacki, Karla J; Cawthorn, William P

2018-01-01

The last decade has seen a resurgence in the study of bone marrow adipose tissue (BMAT) across diverse fields such as metabolism, haematopoiesis, skeletal biology and cancer. Herein, we review the most recent developments of BMAT research in both humans and rodents, including the distinct nature of BMAT; the autocrine, paracrine and endocrine interactions between BMAT and various tissues, both in physiological and pathological scenarios; how these interactions might impact energy metabolism; and the most recent technological advances to quantify BMAT. Though still dwarfed by research into white and brown adipose tissues, BMAT is now recognised as endocrine organ and is attracting increasing attention from biomedical researchers around the globe. We are beginning to learn the importance of BMAT both within and beyond the bone, allowing us to better appreciate the role of BMAT in normal physiology and disease.

Mechanism of action of chromogranin A on catecholamine release: molecular modeling of the catestatin region reveals a β-strand/loop/β-strand structure secured by hydrophobic interactions and predictive of activity

PubMed Central

Tsigelny, Igor; Mahata, Sushil K.; Taupenot, Laurent; Preece, Nicholas E.; Mahata, Manjula; Khan, Imran; Parmer, Robert J.; O’Connor, Daniel T.

2009-01-01

A novel fragment of chromogranin A, known as ‘catestatin’ (bovine chromogranin A344–364), inhibits catecholamine release from chromaffin cells and noradrenergic neurons by acting as a non-competitive nicotinic cholinergic antagonist, and may therefore constitute an endogenous autocrine feedback regulator of sympathoadrenal activity. To characterize how this activity depends on the peptide’s structure, we searched for common 3-dimensional motifs for this primary structure or its homologs. Catestatin’s primary structure bore significant (29–35.5% identity, general alignment score 44–57) sequence homology to fragment sequences within three homologs of known 3-dimensional structures, based on solved X-ray crystals: 8FAB, 1PKM, and 2IG2. Each of these sequences exists in nature as a β-strand/loop/β-strand structure, stabilized by hydrophobic interactions between the β-strands. The catestatin structure was stable during molecular dynamics simulations. The catestatin loop contains three Arg residues, whose electropositive side chains form the terminus of the structure, and give rise to substantial uncompensated charge asymmetry in the molecule. A hydrophobic moment plot revealed that catestatin is the only segment of chromogranin A predicted to contain amphiphilic β-strand. Circular dichroism in the far ultraviolet showed substantial (63%) β-sheet structure, especially in a hydrophobic environment. Alanine-substitution mutants of catestatin established a crucial role for the three central arginine residues in the loop (Arg351, Arg353, and Arg358), though not for two arginine residues in the strand region toward the amino-terminus. [125I]Catestatin bound to Torpedo membranes at a site other than the nicotinic agonist binding site. When the catestatin structure was ‘docked’ with the extracellular domain of the Torpedo nicotinic cholinergic receptor, it interacted principally with the β and δ subunits, in a relatively hydrophobic region of the cation pore extracellular orifice, and the complex of ligand and receptor largely occluded the cation pore, providing a structural basis for the non-competitive nicotinic cholinergic antagonist properties of the peptide. We conclude that a homology model of catestatin correctly predicts actual features of the peptide, both physical and biological. The model suggests particular spatial and charge features of the peptide which may serve as starting points in the development of non-peptide mimetics of this endogenous nicotinic cholinergic antagonist. PMID:9809795

Linking JNK Activity to the DNA Damage Response

PubMed Central

Picco, Vincent

2013-01-01

The activity of c-Jun N-terminal kinase (JNK) was initially described as ultraviolet- and oncogene-induced kinase activity on c-Jun. Shortly after this initial discovery, JNK activation was reported for a wider variety of DNA-damaging agents, including γ-irradiation and chemotherapeutic compounds. As the DNA damage response mechanisms were progressively uncovered, the mechanisms governing the activation of JNK upon genotoxic stresses became better understood. In particular, a recent set of papers links the physical breakage in DNA, the activation of the transcription factor NF-κB, the secretion of TNF-α, and an autocrine activation of the JNK pathway. In this review, we will focus on the pathway that is initiated by a physical break in the DNA helix, leading to JNK activation and the resultant cellular consequences. The implications of these findings will be discussed in the context of cancer therapy with DNA-damaging agents. PMID:24349633

Hematopoietic growth factors and human acute leukemia.

PubMed

Löwenberg, B; Touw, I

1988-10-22

The study of myelopoietic maturation arrest in acute myeloblastic leukemia (AML) has been eased by availability of the human recombinant hemopoietic growth factors, macrophage colony stimulating factor (M-CSF), granulocyte-(G-CSF), granulocyte-macrophage-(GM-CSF) and multilineage stimulating factor (IL-3). Nonphysiological expansion of the leukemic population is not due to escape from control by these factors. Proliferation in vitro of AML cells is dependent on the presence of one or several factors in most cases. The pattern of factor-dependency does not correlate with morphological criteria in individual cases, and may thus offer a new tool for classification of AML. Overproduction of undifferentiated cells is not due to abnormal expression of receptors for the stimulating factors acting at an immature level. Rather, autocrine secretion of early acting lymphokines maintains proliferation of the leukemic clone. When looking at causes of leukemic dysregulation, yet undefined inhibitors of differentiation probably are of equal importance as dysequilibrated stimulation by lymphokines.

Peripheral Serotonin: a New Player in Systemic Energy Homeostasis

PubMed Central

Namkung, Jun; Kim, Hail; Park, Sangkyu

2015-01-01

Whole body energy balance is achieved through the coordinated regulation of energy intake and energy expenditure in various tissues including liver, muscle and adipose tissues. A positive energy imbalance by excessive energy intake or insufficient energy expenditure results in obesity and related metabolic diseases. Although there have been many obesity treatment trials aimed at the reduction of energy intake, these strategies have achieved only limited success because of their associated adverse effects. An ancient neurotransmitter, serotonin is among those traditional pharmacological targets for anti-obesity treatment because it exhibits strong anorectic effect in the brain. However, recent studies suggest the new functions of peripheral serotonin in energy homeostasis ranging from the endocrine regulation by gut-derived serotonin to the autocrine/paracrine regulation by adipocyte-derived serotonin. Here, we discuss the role of serotonin in the regulation of energy homeostasis and introduce peripheral serotonin as a possible target for anti-obesity treatment. PMID:26628041

Skin, fascias, and scars: symptoms and systemic connections

PubMed Central

Bordoni, Bruno; Zanier, Emiliano

2014-01-01

Every element or cell in the human body produces substances that communicate and respond in an autocrine or paracrine mode, consequently affecting organs and structures that are seemingly far from each other. The same also applies to the skin. In fact, when the integrity of the skin has been altered, or when its healing process is disturbed, it becomes a source of symptoms that are not merely cutaneous. The skin is an organ, and similar to any other structure, it has different functions in addition to connections with the central and peripheral nervous system. This article examines pathological responses produced by scars, analyzing definitions and differences. At the same time, it considers the subcutaneous fascias, as this connective structure is altered when there is a discontinuous cutaneous surface. The consequence is an ample symptomatology, which is not limited to the body area where the scar is located, such as a postural or trigeminal disorder. PMID:24403836

Phospho-control of TGF-β superfamily signaling

PubMed Central

Wrighton, Katharine H; Lin, Xia; Feng, Xin-Hua

2010-01-01

Members of the transforming growth factor-β (TGF-β) family control a broad range of cellular responses in metazoan organisms via autocrine, paracrine, and endocrine modes. Thus, aberrant TGF-β signaling can play a key role in the pathogenesis of several diseases, including cancer. TGF-β signaling pathways are activated by a short phospho-cascade, from receptor phosphorylation to the subsequent phosphorylation and activation of downstream signal transducers called R-Smads. R-Smad phosphorylation state determines Smad complex assembly/disassembly, nuclear import/export, transcriptional activity and stability, and is thus the most critical event in TGF-β signaling. Dephosphorylation of R-Smads by specific phosphatases prevents or terminates TGF-β signaling, highlighting the need to consider Smad (de)phosphorylation as a tightly controlled and dynamic event. This article illustrates the essential roles of reversible phosphorylation in controlling the strength and duration of TGF-β signaling and the ensuing physiological responses. PMID:19114991

Systemic Nutrient and Stress Signaling via Myokines and Myometabolites.

PubMed

Rai, Mamta; Demontis, Fabio

2016-01-01

Homeostatic systems mount adaptive responses to meet the energy demands of the cell and to compensate for dysfunction in cellular compartments. Such surveillance systems are also active at the organismal level: Nutrient and stress sensing in one tissue can lead to changes in other tissues. Here, we review the emerging understanding of the role of skeletal muscle in regulating physiological homeostasis and disease progression in other tissues. Muscle-specific genetic interventions can induce systemic effects indirectly, via changes in the mass and metabolic demand of muscle, and directly, via the release of muscle-derived cytokines (myokines) and metabolites (myometabolites) in response to nutrients and stress. In turn, myokines and myometabolites signal to various target tissues in an autocrine, paracrine, and endocrine manner, thereby determining organismal resilience to aging, disease, and environmental challenges. We propose that tailoring muscle systemic signaling by modulating myokine and myometabolite levels may combat many degenerative diseases and delay aging.

Pleural innate response activator B cells protect against pneumonia via a GM-CSF-IgM axis

PubMed Central

Chousterman, Benjamin G.; Hilgendorf, Ingo; Robbins, Clinton S.; Theurl, Igor; Gerhardt, Louisa M.S.; Iwamoto, Yoshiko; Quach, Tam D.; Ali, Muhammad; Chen, John W.; Rothstein, Thomas L.; Nahrendorf, Matthias; Weissleder, Ralph

2014-01-01

Pneumonia is a major cause of mortality worldwide and a serious problem in critical care medicine, but the immunophysiological processes that confer either protection or morbidity are not completely understood. We show that in response to lung infection, B1a B cells migrate from the pleural space to the lung parenchyma to secrete polyreactive emergency immunoglobulin M (IgM). The process requires innate response activator (IRA) B cells, a transitional B1a-derived inflammatory subset which controls IgM production via autocrine granulocyte/macrophage colony-stimulating factor (GM-CSF) signaling. The strategic location of these cells, coupled with the capacity to produce GM-CSF–dependent IgM, ensures effective early frontline defense against bacteria invading the lungs. The study describes a previously unrecognized GM-CSF-IgM axis and positions IRA B cells as orchestrators of protective IgM immunity. PMID:24821911

Liposomal Packaging Generates Wnt Protein with In Vivo Biological Activity

PubMed Central

Zhao, Ludan; Kim, Jae-Beom; ten Berge, Derk; Ponnusamy, Karthik; Carre, A. Lyonel; Dudek, Henryk; Zachlederova, Marie; McElhaney, Michael; Brunton, Shirley; Gunzner, Janet; Callow, Marinella; Polakis, Paul; Costa, Mike; Zhang, Xiaoyan M.; Helms, Jill A.; Nusse, Roel

2008-01-01

Wnt signals exercise strong cell-biological and regenerative effects of considerable therapeutic value. There are, however, no specific Wnt agonists and no method for in vivo delivery of purified Wnt proteins. Wnts contain lipid adducts that are required for activity and we exploited this lipophilicity by packaging purified Wnt3a protein into lipid vesicles. Rather than being encapsulated, Wnts are tethered to the liposomal surface, where they enhance and sustain Wnt signaling in vitro. Molecules that effectively antagonize soluble Wnt3a protein but are ineffective against the Wnt3a signal presented by a cell in a paracrine or autocrine manner are also unable to block liposomal Wnt3a activity, suggesting that liposomal packaging mimics the biological state of active Wnts. When delivered subcutaneously, Wnt3a liposomes induce hair follicle neogenesis, demonstrating their robust biological activity in a regenerative context. PMID:18698373

Liposomal packaging generates Wnt protein with in vivo biological activity.

PubMed

Morrell, Nathan T; Leucht, Philipp; Zhao, Ludan; Kim, Jae-Beom; ten Berge, Derk; Ponnusamy, Karthik; Carre, A Lyonel; Dudek, Henryk; Zachlederova, Marie; McElhaney, Michael; Brunton, Shirley; Gunzner, Janet; Callow, Marinella; Polakis, Paul; Costa, Mike; Zhang, Xiaoyan M; Helms, Jill A; Nusse, Roel

2008-08-13

Wnt signals exercise strong cell-biological and regenerative effects of considerable therapeutic value. There are, however, no specific Wnt agonists and no method for in vivo delivery of purified Wnt proteins. Wnts contain lipid adducts that are required for activity and we exploited this lipophilicity by packaging purified Wnt3a protein into lipid vesicles. Rather than being encapsulated, Wnts are tethered to the liposomal surface, where they enhance and sustain Wnt signaling in vitro. Molecules that effectively antagonize soluble Wnt3a protein but are ineffective against the Wnt3a signal presented by a cell in a paracrine or autocrine manner are also unable to block liposomal Wnt3a activity, suggesting that liposomal packaging mimics the biological state of active Wnts. When delivered subcutaneously, Wnt3a liposomes induce hair follicle neogenesis, demonstrating their robust biological activity in a regenerative context.

Roles of insulin-like growth factors in metamorphic development of turbot (Scophthalmus maximus).

PubMed

Jia, Yudong

2018-01-31

Larval turbot (Scophthalmus maximus) undergo metamorphosis, a late post-embryonic developmental event that precedes juvenile transition. Insulin-like growth factors (IGFs) are important endocrine/autocrine/paracrine factors that provide essential signals to control of the embryonic and postnatal development of vertebrate species, including fish. Accumulating evidence suggests that IGFs are involved in regulating the metamorphic development of flatfish. This mini review focus on the functions of all known IGFs (IGF-I and IGF-II) during the metamorphic development of turbot. Information about IGFs and insulin-like growth factors binding proteins (IGFBPs) from other teleosts is also included in this review to provide an overview of IGFs functions in the metamorphic development of turbot. These findings may enhance our understanding of the potential roles of the IGFs system in controlling of flatfish metamorphosis and contributing to the improvement of broodstock management strategies for larval turbot. Copyright © 2018 Elsevier Inc. All rights reserved.

Currently used methods for identification and characterization of hemichannels.

PubMed

Schalper, Kurt A; Palacios-Prado, Nicolás; Orellana, Juan A; Sáez, Juan C

2008-05-01

Connexins and pannexins are vertebrate transmembrane proteins that form hexameric conduits termed hemichannels. Functional hemichannels allow the diffusional transport of ions and small molecules across the plasma membrane and serve as paracrine and autocrine communication pathways. During the last decade, interest in the hemichannel field increased substantially. Today, there is evidence for the existence of connexin hemichannels in vertebrate cells and bulk of information supports their function in diverse physiological and pathological responses. Controversy regarding the molecular identity of the hemichannel type mediating many responses arose recently with the identification of pannexin-based hemichannels. Here, the authors describe the most frequently used methods for studying hemichannels in living mammalian cells and focus on those with which they have more experience. Although the available in vitro evidence is substantial, further studies and possibly new experimental approaches are required to understand the role and properties of connexin and pannexin hemichannels in vivo.

Molecular Mechanisms of Gonadotropin-Releasing Hormone Signaling: Integrating Cyclic Nucleotides into the Network

PubMed Central

Perrett, Rebecca M.; McArdle, Craig A.

2013-01-01

Gonadotropin-releasing hormone (GnRH) is the primary regulator of mammalian reproductive function in both males and females. It acts via G-protein coupled receptors on gonadotropes to stimulate synthesis and secretion of the gonadotropin hormones luteinizing hormone and follicle-stimulating hormone. These receptors couple primarily via G-proteins of the Gq/ll family, driving activation of phospholipases C and mediating GnRH effects on gonadotropin synthesis and secretion. There is also good evidence that GnRH causes activation of other heterotrimeric G-proteins (Gs and Gi) with consequent effects on cyclic AMP production, as well as for effects on the soluble and particulate guanylyl cyclases that generate cGMP. Here we provide an overview of these pathways. We emphasize mechanisms underpinning pulsatile hormone signaling and the possible interplay of GnRH and autocrine or paracrine regulatory mechanisms in control of cyclic nucleotide signaling. PMID:24312080

Extracellular and Intracellular Cyclophilin A, Native and Post-Translationally Modified, Show Diverse and Specific Pathological Roles in Diseases.

PubMed

Xue, Chao; Sowden, Mark P; Berk, Bradford C

2018-05-01

CypA (cyclophilin A) is a ubiquitous and highly conserved protein with peptidyl prolyl isomerase activity. Because of its highly abundant level in the cytoplasm, most studies have focused on the roles of CypA as an intracellular protein. However, emerging evidence suggests an important role for extracellular CypA in the pathogenesis of several diseases through receptor (CD147 or other)-mediated autocrine and paracrine signaling pathways. In this review, we will discuss the shared and unique pathological roles of extracellular and intracellular CypA in human cardiovascular diseases. In addition, the evolving role of post-translational modifications of CypA in the pathogenesis of disease is discussed. Finally, recent studies with drugs specific for extracellular CypA show its importance in disease pathogenesis in several animal models and make extracellular CypA a new therapeutic target. © 2018 American Heart Association, Inc.

The Crossroads of Synaptic Growth Signaling, Membrane Traffic and Neurological Disease: Insights from Drosophila.

PubMed

Deshpande, Mugdha; Rodal, Avital A

2016-02-01

Neurons require target-derived autocrine and paracrine growth factors to maintain proper identity, innervation, homeostasis and survival. Neuronal growth factor signaling is highly dependent on membrane traffic, both for the packaging and release of the growth factors themselves, and for regulation of intracellular signaling by their transmembrane receptors. Here, we review recent findings from the Drosophila larval neuromuscular junction (NMJ) that illustrate how specific steps of intracellular traffic and inter-organelle interactions impinge on signaling, particularly in the bone morphogenic protein, Wingless and c-Jun-activated kinase pathways, regulating elaboration and stability of NMJ arbors, construction of synapses and synaptic transmission and homeostasis. These membrane trafficking and signaling pathways have been implicated in human motor neuron diseases including amyotrophic lateral sclerosis and hereditary spastic paraplegia, highlighting their importance for neuronal health and survival. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A high ratio of insulin-like growth factor II/insulin-like growth factor binding protein 2 messenger RNA as a marker for anaplasia in meningiomas.

PubMed

Nordqvist, A C; Peyrard, M; Pettersson, H; Mathiesen, T; Collins, V P; Dumanski, J P; Schalling, M

1997-07-01

Insulin-like growth factors (IGFs) I and II have been implicated as autocrine or paracrine growth promoters. These growth factors bind to specific receptors, and the response is modulated by interaction with IGF-binding proteins (IGFBPs). We observed a strong correlation between anaplastic/atypical histopathology and a high IGF-II/IGFBP-2 mRNA ratio in a set of 68 sporadic meningiomas. A strong correlation was also found between clinical outcome and IGF-II/IGFBP-2 ratio, whereas previously used histochemical markers were less correlated to outcome. We suggest that a high IGF-II/IGFBP-2 mRNA ratio may be a sign of biologically aggressive behavior in meningiomas that can influence treatment strategies. We propose that low IGFBP-2 levels in combination with increased levels of IGF-II would result in more free IGF-II and consequently greater stimulation of proliferation.

C/EBP beta regulation of the tumor necrosis factor alpha gene.

PubMed Central

Pope, R M; Leutz, A; Ness, S A

1994-01-01

Activated macrophages contribute to chronic inflammation by the secretion of cytokines and proteinases. Tumor necrosis factor alpha (TNF alpha) is particularly important in this process because of its ability to regulate other inflammatory mediators in an autocrine and paracrine fashion. The mechanism(s) responsible for the cell type-specific regulation of TNF alpha is not known. We present data to show that the expression of TNF alpha is regulated by the transcription factor C/EBP beta (NF-IL6). C/EBP beta activated the TNF alpha gene promoter in cotransfection assays and bound to it at a site which failed to bind the closely related protein C/EBP alpha. Finally, a dominant-negative version of C/EBP beta blocked TNF alpha promoter activation in myeloid cells. Our results implicate C/EBP beta as an important regulator of TNF alpha by myelomonocytic cells. Images PMID:7929820

Placenta accreta: diagnosis, management and the molecular biology of the morbidly adherent placenta.

PubMed

Goh, William A; Zalud, Ivica

2016-01-01

Placenta accreta is now the chief cause of postpartum hemorrhage resulting in maternal and neonatal morbidity. Prenatal diagnosis decreases blood loss at delivery and intra and post-partum complications. Ultrasound is critical for diagnosis and MRI is a complementary tool when the diagnosis is uncertain. Peripartum hysterectomy has been the standard of therapy but conservative management is increasingly being used. The etiology of accreta is due to a deficiency of maternal decidua resulting in placental invasion into the uterine myometrium. The molecular basis for the development of invasive placentation is yet to be elucidated but may involve abnormal paracrine/autocrine signaling between the deficient maternal decidua and the trophoblastic tissue. The interaction of hormones such as Relaxin which is abundant in maternal decidua and insulin-like 4, an insulin-like peptide found in placental trophoblastic tissue may play role in the formation of placenta accreta.

Placenta accreta: Diagnosis, management and the molecular biology of the morbidly adherent placenta

PubMed Central

Goh, William; Zalud, Ivica

2017-01-01

Placenta accreta is now the chief cause of postpartum hemorrhage resulting in maternal and neonatal morbidity. Prenatal diagnosis decreases blood loss at delivery and intra and post-partum complications. Ultrasound is critical for diagnosis and MRI is a complementary tool when the diagnosis is uncertain. Peripartum hysterectomy has been the standard of therapy but conservative management is increasingly being used. The etiology of accreta is due to a deficiency of maternal decidua resulting in placental invasion into the uterine myometrium. The molecular basis for the development of invasive placentation is yet to be elucidated but may involve abnormal paracrine/autocrine signaling between the deficient maternal decidua and the trophoblastic tissue. The interaction of hormones such as Relaxin which is abundant in maternal decidua and INSL4, an insulin like peptide found in placental trophoblastic tissue may play role in the formation of placenta accreta. PMID:26135782

Dual role of mitochondria in producing melatonin and driving GPCR signaling to block cytochrome c release.

PubMed

Suofu, Yalikun; Li, Wei; Jean-Alphonse, Frédéric G; Jia, Jiaoying; Khattar, Nicolas K; Li, Jiatong; Baranov, Sergei V; Leronni, Daniela; Mihalik, Amanda C; He, Yanqing; Cecon, Erika; Wehbi, Vanessa L; Kim, JinHo; Heath, Brianna E; Baranova, Oxana V; Wang, Xiaomin; Gable, Matthew J; Kretz, Eric S; Di Benedetto, Giulietta; Lezon, Timothy R; Ferrando, Lisa M; Larkin, Timothy M; Sullivan, Mara; Yablonska, Svitlana; Wang, Jingjing; Minnigh, M Beth; Guillaumet, Gérald; Suzenet, Franck; Richardson, R Mark; Poloyac, Samuel M; Stolz, Donna B; Jockers, Ralf; Witt-Enderby, Paula A; Carlisle, Diane L; Vilardaga, Jean-Pierre; Friedlander, Robert M

2017-09-19

G protein-coupled receptors (GPCRs) are classically characterized as cell-surface receptors transmitting extracellular signals into cells. Here we show that central components of a GPCR signaling system comprised of the melatonin type 1 receptor (MT 1 ), its associated G protein, and β-arrestins are on and within neuronal mitochondria. We discovered that the ligand melatonin is exclusively synthesized in the mitochondrial matrix and released by the organelle activating the mitochondrial MT 1 signal-transduction pathway inhibiting stress-mediated cytochrome c release and caspase activation. These findings coupled with our observation that mitochondrial MT 1 overexpression reduces ischemic brain injury in mice delineate a mitochondrial GPCR mechanism contributing to the neuroprotective action of melatonin. We propose a new term, "automitocrine," analogous to "autocrine" when a similar phenomenon occurs at the cellular level, to describe this unexpected intracellular organelle ligand-receptor pathway that opens a new research avenue investigating mitochondrial GPCR biology.

Acetylcholine is released from taste cells, enhancing taste signalling

PubMed Central

Dando, Robin; Roper, Stephen D

2012-01-01

Acetylcholine (ACh), a candidate neurotransmitter that has been implicated in taste buds, elicits calcium mobilization in Receptor (Type II) taste cells. Using RT-PCR analysis and pharmacological interventions, we demonstrate that the muscarinic acetylcholine receptor M3 mediates these actions. Applying ACh enhanced both taste-evoked Ca2+ responses and taste-evoked afferent neurotransmitter (ATP) secretion from taste Receptor cells. Blocking muscarinic receptors depressed taste-evoked responses in Receptor cells, suggesting that ACh is normally released from taste cells during taste stimulation. ACh biosensors confirmed that, indeed, taste Receptor cells secrete acetylcholine during gustatory stimulation. Genetic deletion of muscarinic receptors resulted in significantly diminished ATP secretion from taste buds. The data demonstrate a new role for acetylcholine as a taste bud transmitter. Our results imply specifically that ACh is an autocrine transmitter secreted by taste Receptor cells during gustatory stimulation, enhancing taste-evoked responses and afferent transmitter secretion. PMID:22570381

The Adult Drosophila Malpighian Tubules Are Maintained by Pluripotent Stem Cells

PubMed Central

Singh, Shree Ram; Liu, Wei; Hou, Steven X.

2007-01-01

Summary All animals must excrete the waste products of metabolism. Excretion is performed by the kidney in vertebrates and by the Malpighian tubules in Drosophila. The mammalian kidney has an inherent ability for recovery and regeneration following ischemic injury. Stem cells and progenitor cells have been proposed to be responsible for repair and regeneration of injured renal tissue. In Drosophila, the Malpighian tubules are thought to be very stable, and no stem cells have been identified. We have identified pluripotent stem cells in the region of lower tubules and ureters of the Malpighian tubules. Using lineage tracing and molecular marker labeling, we demonstrated that several differentiated cells in the Malpighian tubules arise from the stem cells and an autocrine JAK-STAT signaling regulates the stem cells' self-renewal. Identifying adult kidney stem cells in Drosophila may provide important clues for understanding mammalian kidney repair and regeneration during injury. PMID:18371350

Expression of transforming growth factor alpha and epidermal growth factor receptor messenger RNA in neoplastic and nonneoplastic human kidney tissue.

PubMed

Mydlo, J H; Michaeli, J; Cordon-Cardo, C; Goldenberg, A S; Heston, W D; Fair, W R

1989-06-15

Using Northern blot analysis, we have demonstrated that mRNA for transforming growth factor alpha (TGF-alpha) was expressed in five malignant kidney tissue specimens but was not detected in their autologous nonneoplastic homologues. In addition, the expression of epidermal growth factor (EGF) receptor mRNA in these malignant tissues was 2- to 3-fold greater than in nontransformed tissues. In two cases examined using immunohistochemistry, we were able to correlate the increased expression of the mRNA with an increase in protein expression. Since TGF-alpha is known to bind to the EGF receptor, the finding of an increased expression of both TGF-alpha and EGF receptor mRNA in kidney tumor tissue suggests that interaction between TGF-alpha and the EGF receptor may play a role in promoting transformation and/or proliferation of kidney neoplasms, perhaps by an autocrine mechanism.

A sequential EMT-MET mechanism drives the differentiation of human embryonic stem cells towards hepatocytes.

PubMed

Li, Qiuhong; Hutchins, Andrew P; Chen, Yong; Li, Shengbiao; Shan, Yongli; Liao, Baojian; Zheng, Dejin; Shi, Xi; Li, Yinxiong; Chan, Wai-Yee; Pan, Guangjin; Wei, Shicheng; Shu, Xiaodong; Pei, Duanqing

2017-05-03

Reprogramming has been shown to involve EMT-MET; however, its role in cell differentiation is unclear. We report here that in vitro differentiation of hESCs to hepatic lineage undergoes a sequential EMT-MET with an obligatory intermediate mesenchymal phase. Gene expression analysis reveals that Activin A-induced formation of definitive endoderm (DE) accompanies a synchronous EMT mediated by autocrine TGFβ signalling followed by a MET process. Pharmacological inhibition of TGFβ signalling blocks the EMT as well as DE formation. We then identify SNAI1 as the key EMT transcriptional factor required for the specification of DE. Genetic ablation of SNAI1 in hESCs does not affect the maintenance of pluripotency or neural differentiation, but completely disrupts the formation of DE. These results reveal a critical mesenchymal phase during the acquisition of DE, highlighting a role for sequential EMT-METs in both differentiation and reprogramming.

CD10/neutral endopeptidase 24.11 hydrolyzes bombesin-like peptides and regulates the growth of small cell carcinomas of the lung.

PubMed Central

Shipp, M A; Tarr, G E; Chen, C Y; Switzer, S N; Hersh, L B; Stein, H; Sunday, M E; Reinherz, E L

1991-01-01

Bombesin-like peptides are essential autocrine growth factors for many small cell carcinomas (SCCas) of the lung. Herein, we demonstrate that these malignant pulmonary neuroendocrine cells express low levels of the cell surface metalloendopeptidase CD10/neutral endopeptidase 24.11 (CD10/NEP, common acute lymphoblastic leukemia antigen) and that this enzyme hydrolyzes bombesin-like peptides. The growth of bombesin-like peptide-dependent SCC as is inhibited by CD10/NEP and potentiated by CD10/NEP inhibition. The results provide evidence that CD10/NEP is involved in the regulation of tumor cell proliferation. Since SCCa of the lung occurs almost exclusively in cigarette smokers and cigarette smoke inactivates CD10/NEP, decreased cell surface CD10/NEP enzymatic activity may be causally related to the development of SCCa of the lung. Images PMID:1660144

CD10/neutral endopeptidase 24.11 hydrolyzes bombesin-like peptides and regulates the growth of small cell carcinomas of the lung.

PubMed

Shipp, M A; Tarr, G E; Chen, C Y; Switzer, S N; Hersh, L B; Stein, H; Sunday, M E; Reinherz, E L

1991-12-01

Bombesin-like peptides are essential autocrine growth factors for many small cell carcinomas (SCCas) of the lung. Herein, we demonstrate that these malignant pulmonary neuroendocrine cells express low levels of the cell surface metalloendopeptidase CD10/neutral endopeptidase 24.11 (CD10/NEP, common acute lymphoblastic leukemia antigen) and that this enzyme hydrolyzes bombesin-like peptides. The growth of bombesin-like peptide-dependent SCC as is inhibited by CD10/NEP and potentiated by CD10/NEP inhibition. The results provide evidence that CD10/NEP is involved in the regulation of tumor cell proliferation. Since SCCa of the lung occurs almost exclusively in cigarette smokers and cigarette smoke inactivates CD10/NEP, decreased cell surface CD10/NEP enzymatic activity may be causally related to the development of SCCa of the lung.

Normal growth and development in the absence of hepatic insulin-like growth factor I

PubMed Central

Yakar, Shoshana; Liu, Jun-Li; Stannard, Bethel; Butler, Andrew; Accili, Domenici; Sauer, Brian; LeRoith, Derek

1999-01-01

The somatomedin hypothesis proposed that insulin-like growth factor I (IGF-I) was a hepatically derived circulating mediator of growth hormone and is a crucial factor for postnatal growth and development. To reassess this hypothesis, we have used the Cre/loxP recombination system to delete the igf1 gene exclusively in the liver. igf1 gene deletion in the liver abrogated expression of igf1 mRNA and caused a dramatic reduction in circulating IGF-I levels. However, growth as determined by body weight, body length, and femoral length did not differ from wild-type littermates. Although our model proves that hepatic IGF-I is indeed the major contributor to circulating IGF-I levels in mice it challenges the concept that circulating IGF-I is crucial for normal postnatal growth. Rather, our model provides direct evidence for the importance of the autocrine/paracrine role of IGF-I. PMID:10377413

TRANSCRIPTIONAL INHIBITION OF INTERLEUKIN-12 PROMOTER ACTIVITY IN LEISHMANIA SPP.-INFECTED MACROPHAGES

PubMed Central

Jayakumar, Asha; Widenmaier, Robyn; Ma, Xiaojing; McDowell, Mary Ann

2009-01-01

To establish and persist within a host, Leishmania spp. parasites delay the onset of cell-mediated immunity by suppressing interleukin-12 (IL-12) production from host macrophages. Although it is established that Leishmania spp.-infected macrophages have impaired IL-12 production, the mechanisms that account for this suppression remain to be completely elucidated. Using a luciferase reporter assay assessing IL-12 transcription, we report here that Leishmania major, Leishmania donovani, and Leishmania chagasi inhibit IL-12 transcription in response to interferon-gamma, lipopolysaccharide, and CD40 ligand and that Leishmania spp. lipophosphoglycan, phosphoglycans, and major surface protein are not necessary for inhibition. In addition, all the Leishmania spp. strains and life-cycle stages tested inhibited IL-12 promoter activity. Our data further reveal that autocrine-acting host factors play no role in the inhibitory response and that phagocytosis signaling is necessary for inhibition of IL-12. PMID:18372625

Regulatory Innate Lymphoid Cells Control Innate Intestinal Inflammation.

PubMed

Wang, Shuo; Xia, Pengyan; Chen, Yi; Qu, Yuan; Xiong, Zhen; Ye, Buqing; Du, Ying; Tian, Yong; Yin, Zhinan; Xu, Zhiheng; Fan, Zusen

2017-09-21

An emerging family of innate lymphoid cells (termed ILCs) has an essential role in the initiation and regulation of inflammation. However, it is still unclear how ILCs are regulated in the duration of intestinal inflammation. Here, we identify a regulatory subpopulation of ILCs (called ILCregs) that exists in the gut and harbors a unique gene identity that is distinct from that of ILCs or regulatory T cells (Tregs). During inflammatory stimulation, ILCregs can be induced in the intestine and suppress the activation of ILC1s and ILC3s via secretion of IL-10, leading to protection against innate intestinal inflammation. Moreover, TGF-β1 is induced by ILCregs during the innate intestinal inflammation, and autocrine TGF-β1 sustains the maintenance and expansion of ILCregs. Therefore, ILCregs play an inhibitory role in the innate immune response, favoring the resolution of intestinal inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterization and distribution of GHRH, PACAP, TRH, SST and IGF1 mRNAs in the green iguana.

PubMed

Ávila-Mendoza, José; Pérez-Rueda, Ernesto; Urban-Sosa, Valeria; Carranza, Martha; Martínez-Moreno, Carlos G; Luna, Maricela; Arámburo, Carlos

2018-01-01

The somatotropic axis (SA) regulates numerous aspects of vertebrate physiology such as development, growth, and metabolism and has influence on several tissues including neural, immune, reproductive and gastric tract. Growth hormone (GH) is a key component of SA, it is synthesized and released mainly by pituitary somatotrophs, although now it is known that virtually all tissues can express GH, which, in addition to its well-described endocrine roles, also has autocrine/paracrine/intracrine actions. In the pituitary, GH expression is regulated by several hypothalamic neuropeptides including GHRH, PACAP, TRH and SST. GH, in turn, regulates IGF1 synthesis in several target tissues, adding complexity to the system since GH effects can be exerted either directly or mediated by IGF1. In reptiles, little is known about the SA components and their functional interactions. The aim of this work was to characterize the mRNAs of the principal SA components in the green iguana and to develop the tools that allow the study of the structural and functional evolution of this system in reptiles. By employing RT-PCR and RACE, the cDNAs encoding for GHRH, PACAP, TRH, SST and IGF1 were amplified and sequenced. Results showed that these cDNAs coded for the corresponding protein precursors of 154, 170, 243, 113, and 131 amino acids, respectively. Of these, GHRH, PACAP, SST and IGF1 precursors exhibited a high structural conservation with respect to its counterparts in other vertebrates. On the other hand, iguana's TRH precursor showed 7 functional copies of mature TRH (pyr-QHP-NH 2 ), as compared to 4 and 6 copies of TRH in avian and mammalian proTRH sequences, respectively. It was found that in addition to its primary production site (brain for GHRH, PACAP, TRH and SST, and liver for IGF1), they were also expressed in other peripheral tissues, i.e. testes and ovaries expressed all the studied mRNAs, whereas TRH and IGF1 mRNAs were observed ubiquitously in all tissues considered. These results show that the main SA components in reptiles of the Squamata Order maintain a good structural conservation among vertebrate phylogeny, and suggest important physiological interactions (endocrine, autocrine and/or paracrine) between them due to their wide peripheral tissue expression. Copyright © 2017 Elsevier Inc. All rights reserved.

An autocrine ATP release mechanism regulates basal ciliary activity in airway epithelium.

PubMed

Droguett, Karla; Rios, Mariana; Carreño, Daniela V; Navarrete, Camilo; Fuentes, Christian; Villalón, Manuel; Barrera, Nelson P

2017-07-15

Extracellular ATP, in association with [Ca 2+ ] i regulation, is required to maintain basal ciliary beat frequency. Increasing extracellular ATP levels increases ciliary beating in airway epithelial cells, maintaining a sustained response by inducing the release of additional ATP. Extracellular ATP levels in the millimolar range, previously associated with pathophysiological conditions of the airway epithelium, produce a transient arrest of ciliary activity. The regulation of ciliary beat frequency is dependent on ATP release by hemichannels (connexin/pannexin) and P2X receptor activation, the blockage of which may even stop ciliary movement. The force exerted by cilia, measured by atomic force microscopy, is reduced following extracellular ATP hydrolysis. This result complements the current understanding of the ciliary beating regulatory mechanism, with special relevance to inflammatory diseases of the airway epithelium that affect mucociliary clearance. Extracellular nucleotides, including ATP, are locally released by the airway epithelium and stimulate ciliary activity in a [Ca 2+ ] i -dependent manner after mechanical stimulation of ciliated cells. However, it is unclear whether the ATP released is involved in regulating basal ciliary activity and mediating changes in ciliary activity in response to chemical stimulation. In the present study, we evaluated ciliary beat frequency (CBF) and ciliary beating forces in primary cultures from mouse tracheal epithelium, using videomicroscopy and atomic force microscopy (AFM), respectively. Extracellular ATP levels and [Ca 2+ ] i were measured by luminometric and fluorimetric assays, respectively. Uptake of ethidium bromide was measured to evaluate hemichannel functionality. We show that hydrolysis of constitutive extracellular ATP levels with apyrase (50 U ml -1 ) reduced basal CBF by 45% and ciliary force by 67%. The apyrase effect on CBF was potentiated by carbenoxolone, a hemichannel inhibitor, and oxidized ATP, an antagonist used to block P2X7 receptors, which reduced basal CBF by 85%. Additionally, increasing extracellular ATP levels (0.1-100 μm) increased CBF, maintaining a sustained response that was suppressed in the presence of carbenoxolone. We also show that high levels of ATP (1 mm), associated with inflammatory conditions, lowered basal CBF by reducing [Ca 2+ ] i and hemichannel functionality. In summary, we provide evidence indicating that airway epithelium ATP release is the molecular autocrine mechanism regulating basal ciliary activity and is also the mediator of the ciliary response to chemical stimulation. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Interleukin-8 (IL-8) over-production and autocrine cell activation are key factors in monomethylarsonous acid [MMA(III)]-induced malignant transformation of urothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Escudero-Lourdes, C., E-mail: cescuder@uaslp.mx; Wu, T.; Camarillo, J.M.

2012-01-01

The association between chronic human exposure to arsenicals and bladder cancer development is well recognized; however, the underlying molecular mechanisms have not been fully determined. We propose that inflammatory responses can play a pathogenic role in arsenic-related bladder carcinogenesis. In previous studies, it was demonstrated that chronic exposure to 50 nM monomethylarsenous acid [MMA(III)] leads to malignant transformation of an immortalized model of urothelial cells (UROtsa), with only 3 mo of exposure necessary to trigger the transformation-related changes. In the three-month window of exposure, the cells over-expressed pro-inflammatory cytokines (IL-1β, IL-6 and IL-8), consistent with the sustained activation of NFKβmore » and AP1/c-jun, ERK2, and STAT3. IL-8 was over-expressed within hours after exposure to MMA(III), and sustained over-expression was observed during chronic exposure. In this study, we profiled IL-8 expression in UROtsa cells exposed to 50 nM MMA(III) for 1 to 5 mo. IL-8 expression was increased mainly in cells after 3 mo MMA(III) exposure, and its production was also found increased in tumors derived from these cells after heterotransplantation in SCID mice. UROtsa cells do express both receptors, CXCR1 and CXCR2, suggesting that autocrine cell activation could be important in cell transformation. Supporting this observation and consistent with IL-8 over-expression, CXCR1 internalization was significantly increased after three months of exposure to MMA(III). The expression of MMP-9, cyclin D1, bcl-2, and VGEF was significantly increased in cells exposed to MMA(III) for 3 mo, but these mitogen-activated kinases were significantly decreased after IL-8 gene silencing, together with a decrease in cell proliferation rate and in anchorage-independent colony formation. These results suggest a relevant role of IL-8 in MMA(III)-induced UROtsa cell transformation. -- Highlights: ► IL-8 is over-expressed in human MMA(III)-exposed urothelial cells. ► Internal CXCR1 and tumor progression markers are also increased. ► IL-8 silencing decreased malignant transformation markers in MMA(III)-exposed cells.« less

Brain-derived neurotrophic factor (BDNF) -TrKB signaling modulates cancer-endothelial cells interaction and affects the outcomes of triple negative breast cancer

PubMed Central

Tsai, Yi-Fang; Hsu, Chih-Yi; Yang, Muh-Hwa; Shyr, Yi-Ming

2017-01-01

Aims There is good evidence that the tumor microenvironment plays an important role in cancer metastasis and progression. Our previous studies have shown that brain-derived neurotrophic factor (BDNF) participates in the process of metastasis and in the migration of cancer cells. The aim of this study was to investigate the role of BDNF on the tumor cell microenvironment, namely, the cancer cell-endothelial cell interaction of TNBC cells. Methods We conducted oligoneucleotide microarray analysis of potential biomarkers that are able to differentiate recurrent TNBC from non-recurrent TNBC. The MDA-MB-231 and human endothelial HUVEC lines were used for this study and our approaches included functional studies, such as migration assay, as well as Western blot and real-time PCR analysis of migration and angiogenic signaling. In addition, we analyzed the survival outcome of TNBC breast cancer patients according to their expression level of BDNF using clinical samples. Results The results demonstrated that BDNF was able to bring about autocrinal (MDA-MB-231) and paracrinal (HUVECs) regulation of BDNF-TrkB gene expression and this affected cell migratory activity. The BDNF-induced migratory activity was blocked by inhibitors of ERK, PI3K and TrkB when MDA-MB-231 cells were examined, but only an inhibitor of ERK blocked this activity when HUVEC cells were used. Furthermore, decreased migratory activity was found for △BDNF and △TrkB cell lines. Ingenuity pathway analysis (IPA) of MDA-MB-231 cells showed that BDNF is a key factor that is able to regulate a network made up of metalloproteases and calmodulin. Protein expression levels in a tissue array of tumor slices were found to be correlated with patient prognosis and the results showed that there was significant correlation of TrkB expression, but not of BDNF. expressionwith patient DFS and OS. Conclusion Our study demonstrates that up-regulation of the BDNF signaling pathway seems tobe involved in the mechanism associated with early recurrence in triple negative breast cancer cell. In addition, BDNF can function in either an autocrine or a paracrine manner to increase the migration ability of both MDA-MB-231 cells and HUVEC cells. Finally, overexpression of TrkB, but not of BDNF, is significantly associated with a poor survival outcome for TNBC patients. PMID:28604807

Brain-derived neurotrophic factor (BDNF) -TrKB signaling modulates cancer-endothelial cells interaction and affects the outcomes of triple negative breast cancer.

PubMed

Tsai, Yi-Fang; Tseng, Ling-Ming; Hsu, Chih-Yi; Yang, Muh-Hwa; Chiu, Jen-Hwey; Shyr, Yi-Ming

2017-01-01

There is good evidence that the tumor microenvironment plays an important role in cancer metastasis and progression. Our previous studies have shown that brain-derived neurotrophic factor (BDNF) participates in the process of metastasis and in the migration of cancer cells. The aim of this study was to investigate the role of BDNF on the tumor cell microenvironment, namely, the cancer cell-endothelial cell interaction of TNBC cells. We conducted oligoneucleotide microarray analysis of potential biomarkers that are able to differentiate recurrent TNBC from non-recurrent TNBC. The MDA-MB-231 and human endothelial HUVEC lines were used for this study and our approaches included functional studies, such as migration assay, as well as Western blot and real-time PCR analysis of migration and angiogenic signaling. In addition, we analyzed the survival outcome of TNBC breast cancer patients according to their expression level of BDNF using clinical samples. The results demonstrated that BDNF was able to bring about autocrinal (MDA-MB-231) and paracrinal (HUVECs) regulation of BDNF-TrkB gene expression and this affected cell migratory activity. The BDNF-induced migratory activity was blocked by inhibitors of ERK, PI3K and TrkB when MDA-MB-231 cells were examined, but only an inhibitor of ERK blocked this activity when HUVEC cells were used. Furthermore, decreased migratory activity was found for △BDNF and △TrkB cell lines. Ingenuity pathway analysis (IPA) of MDA-MB-231 cells showed that BDNF is a key factor that is able to regulate a network made up of metalloproteases and calmodulin. Protein expression levels in a tissue array of tumor slices were found to be correlated with patient prognosis and the results showed that there was significant correlation of TrkB expression, but not of BDNF. expressionwith patient DFS and OS. Our study demonstrates that up-regulation of the BDNF signaling pathway seems tobe involved in the mechanism associated with early recurrence in triple negative breast cancer cell. In addition, BDNF can function in either an autocrine or a paracrine manner to increase the migration ability of both MDA-MB-231 cells and HUVEC cells. Finally, overexpression of TrkB, but not of BDNF, is significantly associated with a poor survival outcome for TNBC patients.

KIT Signaling Promotes Growth of Colon Xenograft Tumors in Mice and Is Up-Regulated in a Subset of Human Colon Cancers.

PubMed

Chen, Evan C; Karl, Taylor A; Kalisky, Tomer; Gupta, Santosh K; O'Brien, Catherine A; Longacre, Teri A; van de Rijn, Matt; Quake, Stephen R; Clarke, Michael F; Rothenberg, Michael E

2015-09-01

Receptor tyrosine kinase (RTK) inhibitors have advanced colon cancer treatment. We investigated the role of the RTK KIT in development of human colon cancer. An array of 137 patient-derived colon tumors and their associated xenografts were analyzed by immunohistochemistry to measure levels of KIT and its ligand KITLG. KIT and/or KITLG was stably knocked down by expression of small hairpin RNAs from lentiviral vectors in DLD1, HT29, LS174T, and COLO320 DM colon cancer cell lines, and in UM-COLON#8 and POP77 xenografts; cells transduced with only vector were used as controls. Cells were analyzed by real-time quantitative reverse transcription polymerase chain reaction, single-cell gene expression analysis, flow cytometry, and immunohistochemical, immunoblot, and functional assays. Xenograft tumors were grown from control and KIT-knockdown DLD1 and UM-COLON#8 cells in immunocompromised mice and compared. Some mice were given the RTK inhibitor imatinib after injection of cancer cells; tumor growth was measured based on bioluminescence. We assessed tumorigenicity using limiting dilution analysis. KIT and KITLG were expressed heterogeneously by a subset of human colon tumors. Knockdown of KIT decreased proliferation of colon cancer cell lines and growth of xenograft tumors in mice compared with control cells. KIT knockdown cells had increased expression of enterocyte markers, decreased expression of cycling genes, and, unexpectedly, increased expression of LGR5 associated genes. No activating mutations in KIT were detected in DLD1, POP77, or UM-COLON#8 cells. However, KITLG-knockdown DLD1 cells formed smaller xenograft tumors than control cells. Gene expression analysis of single CD44(+) cells indicated that KIT can promote growth via KITLG autocrine and/or paracrine signaling. Imatinib inhibited growth of KIT(+) colon cancer organoids in culture and growth of xenograft tumors in mice. Cancer cells with endogenous KIT expression were more tumorigenic in mice. KIT and KITLG are expressed by a subset of human colon tumors. KIT signaling promotes growth of colon cancer cells and organoids in culture and xenograft tumors in mice via its ligand, KITLG, in an autocrine or paracrine manner. Patients with KIT-expressing colon tumors can benefit from KIT RTK inhibitors. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

The inhibition of FGF receptor 1 activity mediates sorafenib antiproliferative effects in human malignant pleural mesothelioma tumor-initiating cells.

PubMed

Pattarozzi, Alessandra; Carra, Elisa; Favoni, Roberto E; Würth, Roberto; Marubbi, Daniela; Filiberti, Rosa Angela; Mutti, Luciano; Florio, Tullio; Barbieri, Federica; Daga, Antonio

2017-05-25

Malignant pleural mesothelioma is an aggressive cancer, characterized by rapid progression and high mortality. Persistence of tumor-initiating cells (TICs, or cancer stem cells) after cytotoxic drug treatment is responsible for tumor relapse, and represents one of the main reasons for the poor prognosis of mesothelioma. In fact, identification of the molecules affecting TIC viability is still a significant challenge. TIC-enriched cultures were obtained from 10 human malignant pleural mesotheliomas and cultured in vitro. Three fully characterized tumorigenic cultures, named MM1, MM3, and MM4, were selected and used to assess antiproliferative effects of the multi-kinase inhibitor sorafenib. Cell viability was investigated by MTT assay, and cell cycle analysis as well as induction of apoptosis were determined by flow cytometry. Western blotting was performed to reveal the modulation of protein expression and the phosphorylation status of pathways associated with sorafenib treatment. We analyzed the molecular mechanisms of the antiproliferative effects of sorafenib in mesothelioma TIC cultures. Sorafenib inhibited cell cycle progression in all cultures, but only in MM3 and MM4 cells was this effect associated with Mcl-1-dependent apoptosis. To investigate the mechanisms of sorafenib-mediated antiproliferative activity, TICs were treated with epidermal growth factor (EGF) or basic fibroblast growth factor (bFGF) causing, in MM3 and MM4 cells, MEK, ERK1/2, Akt, and STAT3 phosphorylation. These effects were abolished by sorafenib only in bFGF-treated cells, while a modest inhibition occurred after EGF stimulation, suggesting that sorafenib effects are mainly due to FGF receptor (FGFR) inhibition. Indeed, FGFR1 phosphorylation was inhibited by sorafenib. Moreover, in MM1 cells, which release high levels of bFGF and showed autocrine activation of FGFR1 and constitutive phosphorylation/activation of MEK-ERK1/2, sorafenib induced a more effective antiproliferative response, confirming that the main target of the drug is the inhibition of FGFR1 activity. These results suggest that, in malignant pleural mesothelioma TICs, bFGF signaling is the main target of the antiproliferative response of sorafenib, acting directly on the FGFR1 activation. Patients with constitutive FGFR1 activation via an autocrine loop may be more sensitive to sorafenib treatment and the analysis of this possibility warrants further clinical investigation.

Co-Expression of α9β1 Integrin and VEGF-D Confers Lymphatic Metastatic Ability to a Human Breast Cancer Cell Line MDA-MB-468LN

PubMed Central

Majumder, Mousumi; Rodriguez-Torres, Mauricio; Torres-Garcia, Jose; Wiebe, Ryan; Timoshenko, Alexander V.; Bhattacharjee, Rabindra N.; Chambers, Ann F.; Lala, Peeyush K.

2012-01-01

Introduction and Objectives Lymphatic metastasis is a common occurrence in human breast cancer, mechanisms remaining poorly understood. MDA-MB-468LN (468LN), a variant of the MDA-MB-468GFP (468GFP) human breast cancer cell line, produces extensive lymphatic metastasis in nude mice. 468LN cells differentially express α9β1 integrin, a receptor for lymphangiogenic factors VEGF-C/-D. We explored whether (1) differential production of VEGF-C/-D by 468LN cells provides an autocrine stimulus for cellular motility by interacting with α9β1 and a paracrine stimulus for lymphangiogenesis in vitro as measured with capillary-like tube formation by human lymphatic endothelial cells (HMVEC-dLy); (2) differential expression of α9 also promotes cellular motility/invasiveness by interacting with macrophage derived factors; (3) stable knock-down of VEGF-D or α9 in 468LN cells abrogates lymphangiogenesis and lymphatic metastasis in vivo in nude mice. Results A comparison of expression of cyclo-oxygenase (COX)-2 (a VEGF-C/-D inducer), VEGF-C/-D and their receptors revealed little COX-2 expression by either cells. However, 468LN cells showed differential VEGF-D and α9β1 expression, VEGF-D secretion, proliferative, migratory/invasive capacities, latter functions being stimulated further with VEGF-D. The requirement of α9β1 for native and VEGF-D-stimulated proliferation, migration and Erk activation was demonstrated by treating with α9β1 blocking antibody or knock-down of α9. An autocrine role of VEGF-D in migration was shown by its impairment by silencing VEGF-D and restoration with VEGF-D. 468LN cells and their soluble products stimulated tube formation, migration/invasiveness of HMVEC-dLy cell in a VEGF-D dependent manner as indicated by the loss of stimulation by silencing VEGF-D in 468LN cells. Furthermore, 468LN cells showed α9-dependent stimulation of migration/invasiveness by macrophage products. Finally, capacity for intra-tumoral lymphangiogenesis and lymphatic metastasis in nude mice was completely abrogated by stable knock-down of either VEGF-D or α9 in 468LN cells. Conclusion Differential capacity for VEGF-D production and α9β1 integrin expression by 468LN cells jointly contributed to their lymphatic metastatic phenotype. PMID:22545097

The Differentiation of Human Adipose-Derived Stem Cells towards a Urothelium-Like Phenotype In Vitro and the Dynamic Temporal Changes of Related Cytokines by Both Paracrine and Autocrine Signal Regulation

PubMed Central

Zhou, Zhe; Zhang, Ke; Zhou, Juan; Zhao, Yang; Wang, Zhong; Lu, Mu-jun

2014-01-01

Purpose To investigate the differentiation ability of human adipose-derived stem cells (ASCs) towards urothelium-like cells in vitro and the dynamic changes of related cytokines and cytokine receptors in the culture medium. Materials and Methods The ASCs were induced using both conditioned media (CM) and the transwell co-culture system with an immortalized urothelium cell line (SV-HUC-1,HUC) for 21 days. Protein and mRNA expression of the mature urothelium specific markers uroplakin-IA (UP-1A) and uroplakin-II (UP-II) were detected by immunofluorescence and quantitative real-time PCR, respectively. Array detection was used to screen 41 cytokines and receptors in the upper medium of urothelium, non-induced ASCs and urothelium-induced ASCs at three time points, early (12 hours), intermediate (7 days) and late (21 days). Results After induction for 7 days, the ASCs grown in both CM and transwell co-culture system expressed uroplakin-IA (13.54±2.00%; 17.28±1.84%) and uroplakin-II (19.49±1.73%; 13.98±1.47%). After induction for 21 days, ASCs grown in co-culture had significantly increased expression of uroplakin-IA (48.03±1.25%; 49.57±2.85%) and uroplakin-II (45.38±2.50%; 46.58±1.95%). In the upper medium of urothelium, 28 cytokines and 8 cytokine receptors had significantly higher expression than the counterpart of non-induced ASCs. After 7 days induction, the expression of 22 cytokines and 8 cytokine receptors was significantly elevated in the upper medium of induced ASCs compared to non-induced ASCs. At the early and intermediate time points, ASCs secreted high levels of relative cytokines and soluble receptors, but their expressions decreased significantly at the late time point. Conclusion The adipose-derived stem cells have the potential to be differentiated into urothelium-like cells in vitro by both CM and transwell co-culture system with mature urothelium. Numerous cytokines and receptors were involved in the differentiation process with dynamic temporal changes by both paracrine and autocrine signal regulation. Further studies should be carried out to determine the detailed mechanism of cytokines and receptors and to enhance the urothelium differentiation efficiency of ASCs. PMID:24752317

The differentiation of human adipose-derived stem cells towards a urothelium-like phenotype in vitro and the dynamic temporal changes of related cytokines by both paracrine and autocrine signal regulation.

PubMed

Zhang, Ming; Xu, Ming-Xi; Zhou, Zhe; Zhang, Ke; Zhou, Juan; Zhao, Yang; Wang, Zhong; Lu, Mu-Jun

2014-01-01

To investigate the differentiation ability of human adipose-derived stem cells (ASCs) towards urothelium-like cells in vitro and the dynamic changes of related cytokines and cytokine receptors in the culture medium. The ASCs were induced using both conditioned media (CM) and the transwell co-culture system with an immortalized urothelium cell line (SV-HUC-1,HUC) for 21 days. Protein and mRNA expression of the mature urothelium specific markers uroplakin-IA (UP-1A) and uroplakin-II (UP-II) were detected by immunofluorescence and quantitative real-time PCR, respectively. Array detection was used to screen 41 cytokines and receptors in the upper medium of urothelium, non-induced ASCs and urothelium-induced ASCs at three time points, early (12 hours), intermediate (7 days) and late (21 days). After induction for 7 days, the ASCs grown in both CM and transwell co-culture system expressed uroplakin-IA (13.54±2.00%; 17.28±1.84%) and uroplakin-II (19.49±1.73%; 13.98±1.47%). After induction for 21 days, ASCs grown in co-culture had significantly increased expression of uroplakin-IA (48.03±1.25%; 49.57±2.85%) and uroplakin-II (45.38±2.50%; 46.58±1.95%). In the upper medium of urothelium, 28 cytokines and 8 cytokine receptors had significantly higher expression than the counterpart of non-induced ASCs. After 7 days induction, the expression of 22 cytokines and 8 cytokine receptors was significantly elevated in the upper medium of induced ASCs compared to non-induced ASCs. At the early and intermediate time points, ASCs secreted high levels of relative cytokines and soluble receptors, but their expressions decreased significantly at the late time point. The adipose-derived stem cells have the potential to be differentiated into urothelium-like cells in vitro by both CM and transwell co-culture system with mature urothelium. Numerous cytokines and receptors were involved in the differentiation process with dynamic temporal changes by both paracrine and autocrine signal regulation. Further studies should be carried out to determine the detailed mechanism of cytokines and receptors and to enhance the urothelium differentiation efficiency of ASCs.

IAP Antagonists Enhance Apoptotic Response to Enzalutamide in Castration-Resistant Prostate Cancer Cells via Autocrine TNF-α Signaling.

PubMed

Pilling, Amanda B; Hwang, Ok; Boudreault, Alain; Laurent, Alain; Hwang, Clara

2017-06-01

Castration-resistant prostate cancer (CRPC) remains incurable and identifying effective treatments continues to present a clinical challenge. Although treatment with enzalutamide, a second generation androgen receptor (AR) antagonist, prolongs survival in prostate cancer patients, responses can be limited by intrinsic resistance or acquired resistance. A potential mechanism of resistance to androgen axis inhibition is evasion of apoptosis. Inhibitor of apoptosis proteins (IAPs) are found to be overexpressed in prostate cancer and function to block apoptosis and promote survival signaling. Novel, small-molecule IAP antagonists, such as AEG40995, are emerging as a strategy to induce apoptosis and increase therapeutic response in cancer. Human prostate cancer cell lines LNCaP and C4-2 were treated with enzalutamide with or without addition of IAP antagonist AEG40995 and proliferation and survival were determined by MTS and clonogenic assay. Western blot was used to evaluate IAP protein expression changes and PARP-1 cleavage was assessed as indication of apoptosis. Flow cytometry was performed to analyze apoptosis in treated cells. Caspase activity was determined by luminescence assay. Quantitative real-time PCR and immunometric ELISA was used to assess TNF-α (transcript and protein levels, respectively) in response to treatment. In this study, we demonstrate that IAP antagonist AEG40995 exhibits minimal effects on prostate cancer cell proliferation or survival, but rapidly degrades cIAP1 protein. Combination treatment with enzalutamide demonstrates that AEG40995 increases apoptosis and reduces proliferation and clonogenic survival in cell line models of prostate cancer. Mechanistically, we demonstrate that apoptosis in response to enzalutamide and IAP antagonist requires activation of caspase-8, suggesting extrinsic/death receptor apoptosis signaling. Assessment of TNF-α in response to combination treatment with enzalutamide and AEG40995 reveals increased mRNA expression and autocrine protein secretion. Blocking TNF-α signaling abrogates the apoptotic response demonstrating that TNF-α plays a critical role in executing cell death in response to this drug combination. These findings suggest that IAP antagonists can increase sensitivity and amplify the caspase-mediated apoptotic response to enzalutamide through TNF-α signaling mechanisms. Combination with an IAP antagonist increases enzalutamide sensitivity, lowers the apoptotic threshold and may combat drug resistance in patients with prostate cancer. Prostate 77:866-877, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Ghrelin O-acyltransferase (GOAT) is expressed in prostate cancer tissues and cell lines and expression is differentially regulated in vitro by ghrelin.

PubMed

Seim, Inge; Jeffery, Penny L; de Amorim, Laura; Walpole, Carina M; Fung, Jenny; Whiteside, Eliza J; Lourie, Rohan; Herington, Adrian C; Chopin, Lisa K

2013-07-23

Ghrelin is a 28 amino acid peptide hormone that is expressed in the stomach and a range of peripheral tissues, where it frequently acts as an autocrine/paracrine growth factor. Ghrelin is modified by a unique acylation required for it to activate its cognate receptor, the growth hormone secretagogue receptor (GHSR), which mediates many of the actions of ghrelin. Recently, the enzyme responsible for adding the fatty acid residue (octanoyl/acyl group) to the third amino acid of ghrelin, GOAT (ghrelin O-acyltransferase), was identified. We used cell culture, quantitative real-time reverse transcription (RT)-PCR and immunohistochemistry to demonstrate the expression of GOAT in prostate cancer cell lines and tissues from patients. Real-time RT-PCR was used to demonstrate the expression of prohormone convertase (PC)1/3, PC2 and furin in prostate cancer cell lines. Prostate-derived cell lines were treated with ghrelin and desacyl ghrelin and the effect on GOAT expression was measured using quantitative RT-PCR. We have demonstrated that GOAT mRNA and protein are expressed in the normal prostate and human prostate cancer tissue samples. The RWPE-1 and RWPE-2 normal prostate-derived cell lines and the LNCaP, DU145, and PC3 prostate cancer cell lines express GOAT and at least one other enzyme that is necessary to produce mature, acylated ghrelin from proghrelin (PC1/3, PC2 or furin). Finally, ghrelin, but not desacyl ghrelin (unacylated ghrelin), can directly regulate the expression of GOAT in the RWPE-1 normal prostate derived cell line and the PC3 prostate cancer cell line. Ghrelin treatment (100nM) for 6 hours significantly decreased GOAT mRNA expression two-fold (P < 0.05) in the PC3 prostate cancer cell line, however, ghrelin did not regulate GOAT expression in the DU145 and LNCaP prostate cancer cell lines. This study demonstrates that GOAT is expressed in prostate cancer specimens and cell lines. Ghrelin regulates GOAT expression, however, this is likely to be cell-type specific. The expression of GOAT in prostate cancer supports the hypothesis that the ghrelin axis has autocrine/paracrine roles. We propose that the RWPE-1 prostate cell line and the PC3 prostate cancer cell line may be useful for investigating GOAT regulation and function.

KIT Signaling Promotes Growth of Colon Xenograft Tumors in Mice and is Upregulated in a Subset of Human Colon Cancers

PubMed Central

Chen, Evan C.; Karl, Taylor A.; Kalisky, Tomer; Gupta, Santosh K.; O’Brien, Catherine A.; Longacre, Teri A.; van de Rijn, Matt; Quake, Stephen R.; Clarke, Michael F.; Rothenberg, Michael E.

2015-01-01

Background & Aims Receptor tyrosine kinase (RTK) inhibitors have advanced colon cancer treatment. We investigated the role of the RTK KIT in development of human colon cancer. Methods An array of 137 patient-derived colon tumors and their associated xenografts were analyzed by immunohistochemistry to measure levels of KIT and its ligand KITLG. KIT and/or KITLG was stably knocked down by expression of small hairpin RNAs from lentiviral vectors in DLD1, HT29, LS174T, and COLO320 colon cancer cell lines, and in UM-COLON#8 and POP77 xenografts; cells transduced with only vector were used as controls. Cells were analyzed by real-time quantitative reverse transcription PCR, single-cell gene expression analysis, flow cytometry, and immunohistochemical, immunoblot, and functional assays. Xenograft tumors were grown from control and KIT-knockdown DLD1 and UM-COLON#8 cells in immunocompromised mice and compared. Some mice were given the RTK inhibitor imatinib following injection of cancer cells; tumor growth was measured based on bioluminescence. We assessed tumorigenicity using limiting dilution analysis. Results KIT and KITLG were expressed heterogeneously by a subset of human colon tumors. Knockdown of KIT decreased proliferation of colon cancer cell lines and growth of xenograft tumors in mice, compared with control cells. KIT knockdown cells had increased expression of enterocyte markers, decreased expression of cycling genes, and, unexpectedly, increased expression of LGR5-associated genes. No activating mutations in KIT were detected in DLD1, POP77, or UM-COLON#8 cell lines. However, KITLG-knockdown DLD1 cells formed smaller xenograft tumors than control cells. Gene expression analysis of single CD44+ cells indicated that KIT may promote growth via KITLG autocrine and/or paracrine signaling. Imatinib inhibited growth of KIT+ colon cancer organoids in culture and growth of xenograft tumors in mice. Cancer cells with endogenous KIT expression were more tumorigenic in mice. Conclusions KIT and KITLG are expressed by a subset of human colon tumors. KIT signaling promotes growth of colon cancer cells and organoids in culture and xenograft tumors in mice via its ligand, KITLG, in an autocrine or paracrine manner. Patients with KIT-expressing colon tumors may benefit from KIT RTK inhibitors. PMID:26026391

Role of insulin-like growth factor-I in the regulation of skeletal muscle adaptation to increased loading

NASA Technical Reports Server (NTRS)

Adams, G. R.

1998-01-01

Adaptations in muscle mass stimulated by changes in muscle loading state entail alternations in the synthesis and degradation of myofiber proteins and the modulation of myonuclear number such that the ratio between the number of myonuclei and the size of the myofibers remains relatively constant. As depicted schematically in Figure 2.6, the literature regarding the role of IGF-in mediating muscle adaptation to alterations in loading state suggests the following conclusions: During periods of increased loading, myofibers upregulate the expression and secretion of IGF-I. Acting as an autocrine and/or paracrine growth factor, IGF-I stimulates myofiber anabolic processes. Acting as a paracrine growth factor, IGF-I also stimulates adjacent satellite cells to enter the cell cycle and proliferate. Continued myofiber production of IGF-I stimulates some satellite cells to differentiate and then fuse with myofibers, thus providing additional myonuclei in order to maintain or reestablish the myonucleus to myofiber size ratios of the enlarged myofibers.

Mutant mouse models and their contribution to our knowledge of corpus luteum development, function and regression.

PubMed

Henkes, Luiz E; Davis, John S; Rueda, Bo R

2003-11-10

The corpus luteum is a unique organ, which is transitory in nature. The development, maintenance and regression of the corpus luteum are regulated by endocrine, paracrine and autocrine signaling events. Defining the specific mediators of luteal development, maintenance and regression has been difficult and often perplexing due to the complexity that stems from the variety of cell types that make up the luteal tissue. Moreover, some regulators may serve dual functions as a luteotropic and luteolytic agent depending on the temporal and spatial environment in which they are expressed. As a result, some confusion is present in the interpretation of in vitro and in vivo studies. More recently investigators have utilized mutant mouse models to define the functional significance of specific gene products. The goal of this mini-review is to identify and discuss mutant mouse models that have luteal anomalies, which may provide some clues as to the significance of specific regulators of corpus luteum function.

Spatial focalization of pheromone/MAPK signaling triggers commitment to cell–cell fusion

PubMed Central

Merlini, Laura

2016-01-01

Cell fusion is universal in eukaryotes for fertilization and development, but what signals this process is unknown. Here, we show in Schizosaccharomyces pombe that fusion does not require a dedicated signal but is triggered by spatial focalization of the same pheromone–GPCR (G-protein-coupled receptor)–MAPK signaling cascade that drives earlier mating events. Autocrine cells expressing the receptor for their own pheromone trigger fusion attempts independently of cell–cell contact by concentrating pheromone release at the fusion focus, a dynamic actin aster underlying the secretion of cell wall hydrolases. Pheromone receptor and MAPK cascade are similarly enriched at the fusion focus, concomitant with fusion commitment in wild-type mating pairs. This focalization promotes cell fusion by immobilizing the fusion focus, thus driving local cell wall dissolution. We propose that fusion commitment is imposed by a local increase in MAPK concentration at the fusion focus, driven by a positive feedback between fusion focus formation and focalization of pheromone release and perception. PMID:27798845

Chromatin remodelling and autocrine TNFα are required for optimal interleukin-6 expression in activated human neutrophils.

PubMed

Zimmermann, Maili; Aguilera, Francisco Bianchetto; Castellucci, Monica; Rossato, Marzia; Costa, Sara; Lunardi, Claudio; Ostuni, Renato; Girolomoni, Giampiero; Natoli, Gioacchino; Bazzoni, Flavia; Tamassia, Nicola; Cassatella, Marco A

2015-01-23

Controversy currently exists about the ability of human neutrophils to produce IL-6. Here, we show that the chromatin organization of the IL-6 genomic locus in human neutrophils is constitutively kept in an inactive configuration. However, we also show that upon exposure to stimuli that trigger chromatin remodelling at the IL-6 locus, such as ligands for TLR8 or, less efficiently, TLR4, highly purified neutrophils express and secrete IL-6. In TLR8-activated neutrophils, but not monocytes, IL-6 expression is preceded by the induction of a latent enhancer located 14 kb upstream of the IL-6 transcriptional start site. In addition, IL-6 induction is potentiated by endogenous TNFα, which prolongs the synthesis of the IκBζ co-activator and sustains C/EBPβ recruitment and histone acetylation at IL-6 regulatory regions. Altogether, these data clarify controversial literature on the ability of human neutrophils to generate IL-6 and uncover chromatin-dependent layers of regulation of IL-6 in these cells.

Human Beta Cells Produce and Release Serotonin to Inhibit Glucagon Secretion from Alpha Cells.

PubMed

Almaça, Joana; Molina, Judith; Menegaz, Danusa; Pronin, Alexey N; Tamayo, Alejandro; Slepak, Vladlen; Berggren, Per-Olof; Caicedo, Alejandro

2016-12-20

In the pancreatic islet, serotonin is an autocrine signal increasing beta cell mass during metabolic challenges such as those associated with pregnancy or high-fat diet. It is still unclear whether serotonin is relevant for regular islet physiology and hormone secretion. Here, we show that human beta cells produce and secrete serotonin when stimulated with increases in glucose concentration. Serotonin secretion from beta cells decreases cyclic AMP (cAMP) levels in neighboring alpha cells via 5-HT 1F receptors and inhibits glucagon secretion. Without serotonergic input, alpha cells lose their ability to regulate glucagon secretion in response to changes in glucose concentration, suggesting that diminished serotonergic control of alpha cells can cause glucose blindness and the uncontrolled glucagon secretion associated with diabetes. Supporting this model, pharmacological activation of 5-HT 1F receptors reduces glucagon secretion and has hypoglycemic effects in diabetic mice. Thus, modulation of serotonin signaling in the islet represents a drug intervention opportunity. Published by Elsevier Inc.

Metabolic changes associated with tumor metastasis, part 1: tumor pH, glycolysis and the pentose phosphate pathway.

PubMed

Payen, Valéry L; Porporato, Paolo E; Baselet, Bjorn; Sonveaux, Pierre

2016-04-01

Metabolic adaptations are intimately associated with changes in cell behavior. Cancers are characterized by a high metabolic plasticity resulting from mutations and the selection of metabolic phenotypes conferring growth and invasive advantages. While metabolic plasticity allows cancer cells to cope with various microenvironmental situations that can be encountered in a primary tumor, there is increasing evidence that metabolism is also a major driver of cancer metastasis. Rather than a general switch promoting metastasis as a whole, a succession of metabolic adaptations is more likely needed to promote different steps of the metastatic process. This review addresses the contribution of pH, glycolysis and the pentose phosphate pathway, and a companion paper summarizes current knowledge regarding the contribution of mitochondria, lipids and amino acid metabolism. Extracellular acidification, intracellular alkalinization, the glycolytic enzyme phosphoglucose isomerase acting as an autocrine cytokine, lactate and the pentose phosphate pathway are emerging as important factors controlling cancer metastasis.

Screening Active Compounds from Garcinia Species Native to China Reveals Novel Compounds Targeting the STAT/JAK Signaling Pathway

PubMed Central

Xu, Linfeng; Lao, Yuanzhi; Zhao, Yanhui; Qin, Jian; Fu, Wenwei; Zhang, Yingjia; Xu, Hongxi

2015-01-01

Natural compounds from medicinal plants are important resources for drug development. In a panel of human tumor cells, we screened a library of the natural products from Garcinia species which have anticancer potential to identify new potential therapeutic leads and discovered that caged xanthones were highly effective at suppressing multiple cancer cell lines. Their anticancer activities mainly depended on apoptosis pathways. For compounds in sensitive cancer line, their mechanisms of mode of action were evaluated. 33-Hydroxyepigambogic acid and 35-hydroxyepigambogic acid exhibited about 1 μM IC50 values against JAK2/JAK3 kinases and less than 1 μM IC50 values against NCI-H1650 cell which autocrined IL-6. Thus these two compounds provided a new antitumor molecular scaffold. Our report describes 33-hydroxyepigambogic acid and 35-hydroxyepigambogic acid that inhibited NCI-H1650 cell growth by suppressing constitutive STAT3 activation via direct inhibition of JAK kinase activity. PMID:26090459

Minireview: Dopaminergic Regulation of Insulin Secretion from the Pancreatic Islet

PubMed Central

Ustione, Alessandro

2013-01-01

Exogenous dopamine inhibits insulin secretion from pancreatic β-cells, but the lack of dopaminergic neurons in pancreatic islets has led to controversy regarding the importance of this effect. Recent data, however, suggest a plausible physiologic role for dopamine in the regulation of insulin secretion. We review the literature underlying our current understanding of dopaminergic signaling that can down-regulate glucose-stimulated insulin secretion from pancreatic islets. In this negative feedback loop, dopamine is synthesized in the β-cells from circulating l-dopa, serves as an autocrine signal that is cosecreted with insulin, and causes a tonic inhibition on glucose-stimulated insulin secretion. On the whole animal scale, l-dopa is produced by cells in the gastrointestinal tract, and its concentration in the blood plasma increases following a mixed meal. By reviewing the outcome of certain types of bariatric surgery that result in rapid amelioration of glucose tolerance, we hypothesize that dopamine serves as an “antiincretin” signal that counterbalances the stimulatory effect of glucagon-like peptide 1. PMID:23744894

The Living Scar – Cardiac Fibroblasts and the Injured Heart

PubMed Central

Rog-Zielinska, Eva A; Norris, Russell A; Kohl, Peter; Markwald, Roger

2015-01-01

Cardiac scars, often perceived as “dead” tissue, are very much alive, with heterocellular activity ensuring the maintenance of structural and mechanical integrity following heart injury. To form a scar, non-myocytes such as fibroblasts, proliferate and are recruited from intra- and extra-cardiac sources. Fibroblasts perform important autocrine and paracrine signalling functions. They also establish mechanical and, as is increasingly evident, electrical junctions with other cells. While fibroblasts were previously thought to act simply as electrical insulators, they may be electrically connected among themselves and, under certain circumstances, to other cells, including cardiomyocytes. A better understanding of these interactions will help target scar structure and function and facilitate the development of novel therapies aimed at modifying scar properties for patient benefit. This review explores available insight and recent concepts on fibroblast integration in the heart, and highlights potential avenues for harnessing their roles to optimise scar function following heart injury such as infarction, and therapeutic interventions such as ablation. PMID:26776094

Fibrinogen-like protein 1, a hepatocyte derived protein is an acute phase reactant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Zhilin; Ukomadu, Chinweike

2008-01-25

Fibrinogen-like protein 1 (FGL1) is a hepatocyte derived protein that is upregulated in regenerating rodent livers following partial hepatectomy. It has been implicated as a mitogen for liver cell proliferation. In this study, we show that recombinant human IL-6 induces FGL1 expression in Hep G2 cells in a pattern similar to those of acute phase reactants. Following induction of acute inflammation in rats by subcutaneous injection of turpentine oil, serum FGL1 levels are also enhanced. Although, a recent report suggests that FGL1 associates almost exclusively with the fibrin matrix, we report here that approximately 20% of the total plasma FGL1more » remains free. The enhancement of FGL1 levels in vitro by IL-6 and its induction after turpentine oil injection suggest that it is an acute phase reactant. Its presence in bound and free forms in the blood also implies biological roles that extend beyond the proposed autocrine effect it has on hepatocytes during regeneration.« less

Mechanical load induces sarcoplasmic wounding and FGF release in differentiated human skeletal muscle cultures

NASA Technical Reports Server (NTRS)

Clarke, M. S.; Feeback, D. L.

1996-01-01

The transduction mechanism (or mechanisms) responsible for converting a mechanical load into a skeletal muscle growth response are unclear. In this study we have used a mechanically active tissue culture model of differentiated human skeletal muscle cells to investigate the relationship between mechanical load, sarcolemma wounding, fibroblast growth factor release, and skeletal muscle cell growth. Using the Flexcell Strain Unit we demonstrate that as mechanical load increases, so too does the amount of sarcolemma wounding. A similar relationship was also observed between the level of mechanical load inflicted on the cells and the amount of bFGF (FGF2) released into the surrounding medium. In addition, we demonstrate that the muscle cell growth response induced by chronic mechanical loading in culture can be inhibited by the presence of an antibody capable of neutralizing the biological activity of FGF. This study provides direct evidence that mechanically induced, sarcolemma wound-mediated FGF release is an important autocrine mechanism for transducing the stimulus of mechanical load into a skeletal muscle growth response.

Colon cancer stem cells dictate tumor growth and resist cell death by production of interleukin-4.

PubMed

Todaro, Matilde; Alea, Mileidys Perez; Di Stefano, Anna B; Cammareri, Patrizia; Vermeulen, Louis; Iovino, Flora; Tripodo, Claudio; Russo, Antonio; Gulotta, Gaspare; Medema, Jan Paul; Stassi, Giorgio

2007-10-11

A novel paradigm in tumor biology suggests that cancer growth is driven by stem-like cells within a tumor. Here, we describe the identification and characterization of such cells from colon carcinomas using the stem cell marker CD133 that accounts around 2% of the cells in human colon cancer. The CD133(+) cells grow in vitro as undifferentiated tumor spheroids, and they are both necessary and sufficient to initiate tumor growth in immunodeficient mice. Xenografts resemble the original human tumor maintaining the rare subpopulation of tumorigenic CD133(+) cells. Further analysis revealed that the CD133(+) cells produce and utilize IL-4 to protect themselves from apoptosis. Consistently, treatment with IL-4Ralpha antagonist or anti-IL-4 neutralizing antibody strongly enhances the antitumor efficacy of standard chemotherapeutic drugs through selective sensitization of CD133(+) cells. Our data suggest that colon tumor growth is dictated by stem-like cells that are treatment resistant due to the autocrine production of IL-4.

Osteoimmunology: the study of the relationship between the immune system and bone tissue.

PubMed

Arboleya, Luis; Castañeda, Santos

2013-01-01

Bone tissue is a highly regulated structure, which plays an essential role in various physiological functions. Through autocrine and paracrine mechanisms, bone tissue is involved in hematopoiesis, influencing the fate of hematopoietic stem cells. There are a number of molecules shared by bone cells and immune system cells indicating that there are multiple connections between the immune system and bone tissue. In order to pool all the knowledge concerning both systems, a new discipline known under the term «osteoimmunology» has been developed. Their progress in recent years has been exponential and allowed us to connect and increase our knowledge in areas not seemingly related such as rheumatoid erosion, postmenopausal osteoporosis, bone metastases or periodontal disease. In this review, we have tried to summarize the most important advances that have occurred in the last decade, especially in those areas of interest related to rheumatology. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Identification and preclinical characterization of AZ-23, a novel, selective, and orally bioavailable inhibitor of the Trk kinase pathway.

PubMed

Thress, Kenneth; Macintyre, Terry; Wang, Haiyun; Whitston, Dave; Liu, Zhong-Ying; Hoffmann, Ethan; Wang, Tao; Brown, Jeffrey L; Webster, Kevin; Omer, Charles; Zage, Peter E; Zeng, Lizhi; Zweidler-McKay, Patrick A

2009-07-01

Tropomyosin-related kinases (TrkA, TrkB, and TrkC) are receptor tyrosine kinases that, along with their ligands, the neurotrophins, are involved in neuronal cell growth, development, and survival. The Trk-neurotrophin pathway may also play a role in tumorigenesis through oncogenic fusions, mutations, and autocrine signaling, prompting the development of novel Trk inhibitors as agents for cancer therapy. This report describes the identification of AZ-23, a novel, potent, and selective Trk kinase inhibitor. In vitro studies with AZ-23 showed improved selectivity over previous compounds and inhibition of Trk kinase activity in cells at low nanomolar concentrations. AZ-23 showed in vivo TrkA kinase inhibition and efficacy in mice following oral administration in a TrkA-driven allograft model and significant tumor growth inhibition in a Trk-expressing xenograft model of neuroblastoma. AZ-23 represents a potent and selective Trk kinase inhibitor from a novel series with the potential for use as a treatment for cancer.

Lysophosphatidic acids, cyclic phosphatidic acids and autotaxin as promising targets in therapies of cancer and other diseases.

PubMed

Gendaszewska-Darmach, Edyta

2008-01-01

Lysophospholipids have long been recognized as membrane phospholipid metabolites, but only recently lysophosphatidic acids (LPA) have been demonstrated to act on specific G protein-coupled receptors. The widespread expression of LPA receptors and coupling to several classes of G proteins allow LPA-dependent regulation of numerous processes, such as vascular development, neurogenesis, wound healing, immunity, and cancerogenesis. Lysophosphatidic acids have been found to induce many of the hallmarks of cancer including cellular processes such as proliferation, survival, migration, invasion, and neovascularization. Furthermore, autotaxin (ATX), the main enzyme converting lysophosphatidylcholine into LPA was identified as a tumor cell autocrine motility factor. On the other hand, cyclic phosphatidic acids (naturally occurring analogs of LPA generated by ATX) have anti-proliferative activity and inhibit tumor cell invasion and metastasis. Research achievements of the past decade suggest implementation of preclinical and clinical evaluation of LPA and its analogs, LPA receptors, as well as autotaxin as potential therapeutic targets.

Orexin A/Hypocretin Modulates Leptin Receptor-Mediated Signaling by Allosteric Modulations Mediated by the Ghrelin GHS-R1A Receptor in Hypothalamic Neurons.

PubMed

Medrano, Mireia; Aguinaga, David; Reyes-Resina, Irene; Canela, Enric I; Mallol, Josefa; Navarro, Gemma; Franco, Rafael

2018-06-01

The hypothalamus is a key integrator of nutrient-seeking signals in the form of hormones and metabolites originated in both the central nervous system and the periphery. The main autocrine and paracrine target of orexinergic-related hormones such as leptin, orexin/hypocretin, and ghrelin are neuropeptide Y neurons located in the arcuate nucleus of the hypothalamus. The aim of this study was to investigate the expression and the molecular and functional relationships between leptin, orexin/hypocretin and ghrelin receptors. Biophysical studies in a heterologous system showed physical interactions between them, with potential formation of heterotrimeric complexes. Functional assays showed robust allosteric interactions particularly different when the three receptors are expressed together. Further biochemical and pharmacological assays provided evidence of heterotrimer functional expression in primary cultures of hypothalamic neurons. These findings constitute evidence of close relationships in the action of the three hormones already starting at the receptor level in hypothalamic cells.

Endocrinology of parturition

PubMed Central

Kota, Sunil K.; Gayatri, Kotni; Jammula, Sruti; Kota, Siva K.; Krishna, S. V. S.; Meher, Lalit K.; Modi, Kirtikumar D.

2013-01-01

The myometrium must remain relatively quiescent during pregnancy to accommodate growth and development of the feto-placental unit, and then must transform into a highly coordinated, strongly contracting organ at the time of labour for successful expulsion of the new born. The control of timing of labour is complex involving interactions between mother, fetus and the placenta. The timely onset of labour and delivery is an important determinant of perinatal outcome. Both preterm birth (delivery before 37 week of gestation) and post term pregnancy (pregnancy continuing beyond 42 weeks) are both associated with a significant increase in perinatal morbidity and mortality. There are multiple paracrine/autocrine events, fetal hormonal changes and overlapping maternal/fetal control mechanisms for the triggering of parturition in women. Our current article reviews the mechanisms for uterine distension and reduced contractions during pregnancy and the parturition cascade responsible for the timely and spontaneous onset of labour at term. It also discusses the mechanisms of preterm labour and post term pregnancy and the clinical implications thereof. PMID:23776853

hCG, the wonder of today's science

PubMed Central

2012-01-01

Background hCG is a wonder. Firstly, because hCG is such an extreme molecule. hCG is the most acidic glycoprotein containing the highest proportion of sugars. Secondly, hCG exists in 5 common forms. Finally, it has so many functions ranging from control of human pregnancy to human cancer. This review examines these molecules in detail. Content These 5 molecules, hCG, sulfated hCG, hyperglycosylated hCG, hCG free beta and hyperglycosylated free beta are produced by placental syncytiotrophoblast cells and pituitary gonadotrope cells (group 1), and by placental cytotrophoblast cells and human malignancies (group 2). Group 1 molecules are both hormones that act on the hCG/LH receptor. These molecules are central to human menstrual cycle and human pregnancy. Group 2 molecules are autocrines, that act by antagonizing a TGF beta receptor. These molecules are critical to all advanced malignancies. Conclusions The hCG groups are molecules critical to both the molecules of pregnancy or human life, and to the advancement of cancer, or human death. PMID:22455390

A Myc-driven self-reinforcing regulatory network maintains mouse embryonic stem cell identity

PubMed Central

Fagnocchi, Luca; Cherubini, Alessandro; Hatsuda, Hiroshi; Fasciani, Alessandra; Mazzoleni, Stefania; Poli, Vittoria; Berno, Valeria; Rossi, Riccardo L.; Reinbold, Rolland; Endele, Max; Schroeder, Timm; Rocchigiani, Marina; Szkarłat, Żaneta; Oliviero, Salvatore; Dalton, Stephen; Zippo, Alessio

2016-01-01

Stem cell identity depends on the integration of extrinsic and intrinsic signals, which directly influence the maintenance of their epigenetic state. Although Myc transcription factors play a major role in stem cell self-renewal and pluripotency, their integration with signalling pathways and epigenetic regulators remains poorly defined. We addressed this point by profiling the gene expression and epigenetic pattern in ESCs whose growth depends on conditional Myc activity. Here we show that Myc potentiates the Wnt/β-catenin signalling pathway, which cooperates with the transcriptional regulatory network in sustaining ESC self-renewal. Myc activation results in the transcriptional repression of Wnt antagonists through the direct recruitment of PRC2 on these targets. The consequent potentiation of the autocrine Wnt/β-catenin signalling induces the transcriptional activation of the endogenous Myc family members, which in turn activates a Myc-driven self-reinforcing circuit. Thus, our data unravel a Myc-dependent self-propagating epigenetic memory in the maintenance of ESC self-renewal capacity. PMID:27301576

Role for herpes simplex virus 1 ICP27 in the inhibition of type I interferon signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Karen E.; Song, Byeongwoon; Knipe, David M.

2008-05-10

Host cells respond to viral infection by many mechanisms, including the production of type I interferons which act in a paracrine and autocrine manner to induce the expression of antiviral interferon-stimulated genes (ISGs). Viruses have evolved means to inhibit interferon signaling to avoid induction of the innate immune response. Herpes simplex virus 1 (HSV-1) has several mechanisms to inhibit type I interferon production, the activities of ISGs, and the interferon signaling pathway itself. We report that the inhibition of the Jak/STAT pathway by HSV-1 requires viral gene expression and that viral immediate-early protein ICP27 plays a role in downregulating STAT-1more » phosphorylation and in preventing the accumulation of STAT-1 in the nucleus. We also show that expression of ICP27 by transfection causes an inhibition of IFN-induced STAT-1 nuclear accumulation. Therefore, ICP27 is necessary and sufficient for at least some of the effects of HSV infection on STAT-1.« less

A drug repositioning approach identifies tricyclic antidepressants as inhibitors of small cell lung cancer and other neuroendocrine tumors

PubMed Central

Jahchan, Nadine S; Dudley, Joel T; Mazur, Pawel K; Flores, Natasha; Yang, Dian; Palmerton, Alec; Zmoos, Anne-Flore; Vaka, Dedeepya; Tran, Kim QT; Zhou, Margaret; Krasinska, Karolina; Riess, Jonathan W; Neal, Joel W; Khatri, Purvesh; Park, Kwon S; Butte, Atul J; Sage, Julien

2013-01-01

Small cell lung cancer (SCLC) is an aggressive neuroendocrine subtype of lung cancer with high mortality. We used a systematic drug-repositioning bioinformatics approach querying a large compendium of gene expression profiles to identify candidate FDA-approved drugs to treat SCLC. We found that tricyclic antidepressants and related molecules potently induce apoptosis in both chemonaïve and chemoresistant SCLC cells in culture, in mouse and human SCLC tumors transplanted into immunocompromised mice, and in endogenous tumors from a mouse model for human SCLC. The candidate drugs activate stress pathways and induce cell death in SCLC cells, at least in part by disrupting autocrine survival signals involving neurotransmitters and their G protein-coupled receptors. The candidate drugs inhibit the growth of other neuroendocrine tumors, including pancreatic neuroendocrine tumors and Merkel cell carcinoma. These experiments identify novel targeted strategies that can be rapidly evaluated in patients with neuroendocrine tumors through the repurposing of approved drugs. PMID:24078773

IL-4 mRNA Is Downregulated in the Liver of Pancreatic Cancer Patients Suffering from Cachexia.

PubMed

Prokopchuk, Olga; Steinacker, Jürgen M; Nitsche, Ulrich; Otto, Stephanie; Bachmann, Jeannine; Schubert, Elaine C; Friess, Helmut; Martignoni, Marc E

2017-01-01

Interleukin-4 (IL-4) together with interleukin-13 (IL-13) play an important role in inflammation and wound repair, and are known to be upregulated in human skeletal muscle after strenuous physical exercise. Additionally, these cytokines may act as autocrine growth factors in pancreatic cancer cells. We hypothesize that IL-4, IL-13, and their corresponding receptors are involved in mechanism of cancer cachexia. Tissue samples from human skeletal muscle, white fat, liver, healthy pancreas, and pancreatic ductal adenocarcinoma were analyzed by quantitative real-time polymerase chain reaction for mRNA expression levels of IL-4, IL-13, IL-4 receptor α, and IL-13 receptor α1. We demonstrate for the first time that liver IL-4 mRNA is downregulated in vivo in patients with pancreatic cancer and cachexia. Additionally, IL-4 mRNA in the liver inversely correlated with musculus psoas thickness. We speculate that suppression of IL-4 is involved in cancer cachexia, although the exact mechanisms have to be further elucidated.

A Myc-driven self-reinforcing regulatory network maintains mouse embryonic stem cell identity.

PubMed

Fagnocchi, Luca; Cherubini, Alessandro; Hatsuda, Hiroshi; Fasciani, Alessandra; Mazzoleni, Stefania; Poli, Vittoria; Berno, Valeria; Rossi, Riccardo L; Reinbold, Rolland; Endele, Max; Schroeder, Timm; Rocchigiani, Marina; Szkarłat, Żaneta; Oliviero, Salvatore; Dalton, Stephen; Zippo, Alessio

2016-06-15

Stem cell identity depends on the integration of extrinsic and intrinsic signals, which directly influence the maintenance of their epigenetic state. Although Myc transcription factors play a major role in stem cell self-renewal and pluripotency, their integration with signalling pathways and epigenetic regulators remains poorly defined. We addressed this point by profiling the gene expression and epigenetic pattern in ESCs whose growth depends on conditional Myc activity. Here we show that Myc potentiates the Wnt/β-catenin signalling pathway, which cooperates with the transcriptional regulatory network in sustaining ESC self-renewal. Myc activation results in the transcriptional repression of Wnt antagonists through the direct recruitment of PRC2 on these targets. The consequent potentiation of the autocrine Wnt/β-catenin signalling induces the transcriptional activation of the endogenous Myc family members, which in turn activates a Myc-driven self-reinforcing circuit. Thus, our data unravel a Myc-dependent self-propagating epigenetic memory in the maintenance of ESC self-renewal capacity.

T helper 1 immunity requires complement-driven NLRP3 inflammasome activity in CD4+ T cells

PubMed Central

Spolski, Rosanne; Robertson, Avril A. B.; Klos, Andreas; Rheinheimer, Claudia; Dutow, Pavel; Woodruff, Trent M.; Yu, Zu Xi; O'Neill, Luke A.; Coll, Rebecca C.; Sher, Alan; Leonard, Warren J.; Köhl, Jörg; Monk, Pete; Cooper, Matthew A.; Arno, Matthew; Afzali, Behdad; Lachmann, Helen J.; Cope, Andrew P.; Mayer-Barber, Katrin D.; Kemper, Claudia

2016-01-01

The NLRP3 inflammasome controls interleukin-1β maturation in antigen-presenting cells, but a direct role for NLRP3 in human adaptive immune cells has not been described. We found that the NLRP3 inflammasome assembles in human CD4+ T cells and initiates caspase-1–dependent interleukin-1β secretion, thereby promoting interferon-γ production and T helper 1 (TH1) differentiation in an autocrine fashion. NLRP3 assembly requires intracellular C5 activation and stimulation of C5a receptor 1 (C5aR1), which is negatively regulated by surface-expressed C5aR2. Aberrant NLRP3 activity in T cells affects inflammatory responses in human autoinflammatory disease and in mouse models of inflammation and infection. Our results demonstrate that NLRP3 inflammasome activity is not confined to “innate immune cells” but is an integral component of normal adaptive TH1 responses. PMID:27313051

T helper 1 immunity requires complement-driven NLRP3 inflammasome activity in CD4⁺ T cells.

PubMed

Arbore, Giuseppina; West, Erin E; Spolski, Rosanne; Robertson, Avril A B; Klos, Andreas; Rheinheimer, Claudia; Dutow, Pavel; Woodruff, Trent M; Yu, Zu Xi; O'Neill, Luke A; Coll, Rebecca C; Sher, Alan; Leonard, Warren J; Köhl, Jörg; Monk, Pete; Cooper, Matthew A; Arno, Matthew; Afzali, Behdad; Lachmann, Helen J; Cope, Andrew P; Mayer-Barber, Katrin D; Kemper, Claudia

2016-06-17

The NLRP3 inflammasome controls interleukin-1β maturation in antigen-presenting cells, but a direct role for NLRP3 in human adaptive immune cells has not been described. We found that the NLRP3 inflammasome assembles in human CD4(+) T cells and initiates caspase-1-dependent interleukin-1β secretion, thereby promoting interferon-γ production and T helper 1 (T(H)1) differentiation in an autocrine fashion. NLRP3 assembly requires intracellular C5 activation and stimulation of C5a receptor 1 (C5aR1), which is negatively regulated by surface-expressed C5aR2. Aberrant NLRP3 activity in T cells affects inflammatory responses in human autoinflammatory disease and in mouse models of inflammation and infection. Our results demonstrate that NLRP3 inflammasome activity is not confined to "innate immune cells" but is an integral component of normal adaptive T(H)1 responses. Copyright © 2016, American Association for the Advancement of Science.

Multifaceted Leptin network: the molecular connection between obesity and breast cancer

PubMed Central

Saxena, Neeraj K.; Sharma, Dipali

2016-01-01

High plasma levels of leptin, a major adipocytokine produced by adipocytes, are correlated with increased fat mass in obese state. Leptin is emerging as a key candidate molecule linking obesity with breast cancer. Acting via endocrine, paracrine, and autocrine manner, leptin impacts various stages of breast tumorigenesis from initiation and primary tumor growth to metastatic progression. Leptin also modulates the tumor microenvironment mainly through supporting migration of endothelial cells, neo-angiogenesis and sustaining recruitment of macrophage and monocytes. Various studies have shown that hyperactive leptin-signaling network leads to concurrent activation of multiple oncogenic pathways resulting in enhanced proliferation, decreased apoptosis, acquisition of mesenchymal phenotype, potentiated migration and enhanced invasion potential of tumor cells. Furthermore, the capability of leptin to interact with other molecular effectors of obese state including, estrogen, IGF-1, insulin, VEGF and inflammatory cytokines further increases its impact on breast tumor progression in obese state. This article presents an overview of the studies investigating the involvement of leptin in breast cancer. PMID:24214584

The molecular profile of microglia under the influence of glioma

PubMed Central

Li, Wei; Graeber, Manuel B.

2012-01-01

Microglia, which contribute substantially to the tumor mass of glioblastoma, have been shown to play an important role in glioma growth and invasion. While a large number of experimental studies on functional attributes of microglia in glioma provide evidence for their tumor-supporting roles, there also exist hints in support of their anti-tumor properties. Microglial activities during glioma progression seem multifaceted. They have been attributed to the receptors expressed on the microglia surface, to glioma-derived molecules that have an effect on microglia, and to the molecules released by microglia in response to their environment under glioma control, which can have autocrine effects. In this paper, the microglia and glioma literature is reviewed. We provide a synopsis of the molecular profile of microglia under the influence of glioma in order to help establish a rational basis for their potential therapeutic use. The ability of microglia precursors to cross the blood–brain barrier makes them an attractive target for the development of novel cell-based treatments of malignant glioma. PMID:22573310

Taste buds as peripheral chemosensory processors

PubMed Central

Roper, Stephen D.

2012-01-01

Taste buds are peripheral chemosensory organs situated in the oral cavity. Each taste bud consists of a community of 50–100 cells that interact synaptically during gustatory stimulation. At least three distinct cell types are found in mammalian taste buds – Type I cells, Receptor (Type II) cells, and Presynaptic (Type III) cells. Type I cells appear to be glial-like cells. Receptor cells express G protein-coupled taste receptors for sweet, bitter, or umami compounds. Presynaptic cells transduce acid stimuli (sour taste). Cells that sense salt (NaCl) taste have not yet been confidently identified in terms of these cell types. During gustatory stimulation, taste bud cells secrete synaptic, autocrine, and paracrine transmitters. These transmitters include ATP, acetylcholine (ACh), serotonin (5-HT), norepinephrine (NE), and GABA. Glutamate is an efferent transmitter that stimulates Presynaptic cells to release 5-HT. This chapter discusses these transmitters, which cells release them, the postsynaptic targets for the transmitters, and how cell–cell communication shapes taste bud signaling via these transmitters. PMID:23261954

Taste buds as peripheral chemosensory processors.

PubMed

Roper, Stephen D

2013-01-01

Taste buds are peripheral chemosensory organs situated in the oral cavity. Each taste bud consists of a community of 50-100 cells that interact synaptically during gustatory stimulation. At least three distinct cell types are found in mammalian taste buds - Type I cells, Receptor (Type II) cells, and Presynaptic (Type III) cells. Type I cells appear to be glial-like cells. Receptor cells express G protein-coupled taste receptors for sweet, bitter, or umami compounds. Presynaptic cells transduce acid stimuli (sour taste). Cells that sense salt (NaCl) taste have not yet been confidently identified in terms of these cell types. During gustatory stimulation, taste bud cells secrete synaptic, autocrine, and paracrine transmitters. These transmitters include ATP, acetylcholine (ACh), serotonin (5-HT), norepinephrine (NE), and GABA. Glutamate is an efferent transmitter that stimulates Presynaptic cells to release 5-HT. This chapter discusses these transmitters, which cells release them, the postsynaptic targets for the transmitters, and how cell-cell communication shapes taste bud signaling via these transmitters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Update on the Mechanisms of Liver Regeneration.

PubMed

Preziosi, Morgan E; Monga, Satdarshan P

2017-05-01

Liver possesses many critical functions such as synthesis, detoxification, and metabolism. It continually receives nutrient-rich blood from gut, which incidentally is also toxin-rich. That may be why liver is uniquely bestowed with a capacity to regenerate. A commonly studied procedure to understand the cellular and molecular basis of liver regeneration is that of surgical resection. Removal of two-thirds of the liver in rodents or patients instigates alterations in hepatic homeostasis, which are sensed by the deficient organ to drive the restoration process. Although the exact mechanisms that initiate regeneration are unknown, alterations in hemodynamics and metabolism have been suspected as important effectors. Key signaling pathways are activated that drive cell proliferation in various hepatic cell types through autocrine and paracrine mechanisms. Once the prehepatectomy mass is regained, the process of regeneration is adequately terminated. This review highlights recent discoveries in the cellular and molecular basis of liver regeneration. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Endometrial proteins: a reappraisal.

PubMed

Seppälä, M; Julkunen, M; Riittinen, L; Koistinen, R

1992-06-01

Uterine factors influence reproduction at the macro-anatomy level, and the effects of hormonal steroids on endometrial morphology are well recognized in the histopathological diagnosis of dysfunctional bleeding and infertility. During the past decade, attention has been paid to endometrial protein synthesis and secretion with respect to endocrine stimuli and implantation, and to the paracrine/autocrine effects of endometrial peptide growth factors, their binding proteins and other factors. The emphasis of this presentation is on protein secretion of the secretory endometrium, in which progesterone plays a pivotal role. Insulin-like growth factors have receptors on the endometrium, and IGF-binding proteins, stimulated by progesterone, modulate the effects of IGFs locally. Also other protein products of the secretory endometrium have been reviewed in this communication, with special emphasis on studies of a progesterone-associated endometrial protein which has many names in the literature, such as PEP, PP14, alpha 2-PEG and AUP. Extensive studies are ongoing in many laboratories to elucidate the regulation, function, interplay at tissue and cellular levels, and clinical significance of these proteins.

Physical effects at the cellular level under altered gravity conditions

NASA Technical Reports Server (NTRS)

Todd, Paul

1992-01-01

Several modifications of differentiated functions of animal cells cultivated in vitro have been reported when cultures have been exposed to increased or decreased inertial acceleration fields by centrifugation, clinorotation, and orbital space flight. Variables modified by clinorotation conditions include inertial acceleration, convection, hydrostatic pressure, sedimentation, and shear stress, which also affect transport processes in the extracellular chemical environment. Autocrine, paracrine and endocrine substances, to which cells are responsive via specific receptors, are usually transported in vitro (and possibly in certain embryos) by convection and in vivo by a circulatory system or ciliary action. Increased inertial acceleration increases convective flow, while microgravity nearly abolishes it. In the latter case the extracellular transport of macromolecules is governed by diffusion. By making certain assumptions it is possible to calculate the Peclet number, the ratio of convective transport to diffusive transport. Some, but not all, responses of cells in vitro to modified inertial environments could be manifestations of modified extracellular convective flow.

Stereotyped responses of Drosophila peptidergic neuronal ensemble depend on downstream neuromodulators

PubMed Central

Mena, Wilson; Diegelmann, Sören; Wegener, Christian; Ewer, John

2016-01-01

Neuropeptides play a key role in the regulation of behaviors and physiological responses including alertness, social recognition, and hunger, yet, their mechanism of action is poorly understood. Here, we focus on the endocrine control ecdysis behavior, which is used by arthropods to shed their cuticle at the end of every molt. Ecdysis is triggered by ETH (Ecdysis triggering hormone), and we show that the response of peptidergic neurons that produce CCAP (crustacean cardioactive peptide), which are key targets of ETH and control the onset of ecdysis behavior, depends fundamentally on the actions of neuropeptides produced by other direct targets of ETH and released in a broad paracrine manner within the CNS; by autocrine influences from the CCAP neurons themselves; and by inhibitory actions mediated by GABA. Our findings provide insights into how this critical insect behavior is controlled and general principles for understanding how neuropeptides organize neuronal activity and behaviors. DOI: http://dx.doi.org/10.7554/eLife.19686.001 PMID:27976997

Cell-To-Cell Communication in Bilateral Macronodular Adrenal Hyperplasia Causing Hypercortisolism

PubMed Central

Lefebvre, Hervé; Duparc, Céline; Prévost, Gaëtan; Bertherat, Jérôme; Louiset, Estelle

2015-01-01

It has been well established that, in the human adrenal gland, cortisol secretion is not only controlled by circulating corticotropin but is also influenced by a wide variety of bioactive signals, including conventional neurotransmitters and neuropeptides, released within the cortex by various cell types such as chromaffin cells, neurons, cells of the immune system, adipocytes, and endothelial cells. These different types of cells are present in bilateral macronodular adrenal hyperplasia (BMAH), a rare etiology of primary adrenal Cushing’s syndrome, where they appear intermingled with adrenocortical cells in the hyperplastic cortex. In addition, the genetic events, which cause the disease, favor abnormal adrenal differentiation that results in illicit expression of paracrine regulatory factors and their receptors in adrenocortical cells. All these defects constitute the molecular basis for aberrant autocrine/paracrine regulatory mechanisms, which are likely to play a role in the pathophysiology of BMAH-associated hypercortisolism. The present review summarizes the current knowledge on this topic as well as the therapeutic perspectives offered by this new pathophysiological concept. PMID:25941513

PUMA amplifies necroptosis signaling by activating cytosolic DNA sensors

PubMed Central

Tong, Jingshan; Yang, Liheng; Wei, Liang; Stolz, Donna B.; Yu, Jian; Zhang, Jianke; Zhang, Lin

2018-01-01

Necroptosis, a form of regulated necrotic cell death, is governed by RIP1/RIP3-mediated activation of MLKL. However, the signaling process leading to necroptotic death remains to be elucidated. In this study, we found that PUMA, a proapoptotic BH3-only Bcl-2 family member, is transcriptionally activated in an RIP3/MLKL-dependent manner following induction of necroptosis. The induction of PUMA, which is mediated by autocrine TNF-α and enhanced NF-κB activity, contributes to necroptotic death in RIP3-expressing cells with caspases inhibited. On induction, PUMA promotes the cytosolic release of mitochondrial DNA and activation of the DNA sensors DAI/Zbp1 and STING, leading to enhanced RIP3 and MLKL phosphorylation in a positive feedback loop. Furthermore, deletion of PUMA partially rescues necroptosis-mediated developmental defects in FADD-deficient embryos. Collectively, our results reveal a signal amplification mechanism mediated by PUMA and cytosolic DNA sensors that is involved in TNF-driven necroptotic death in vitro and in vivo. PMID:29581256

Calcium-activated butyrylcholinesterase in human skin protects acetylcholinesterase against suicide inhibition by neurotoxic organophosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schallreuter, Karin U.; Institute for Pigmentary Disorders in Association with EM Arndt University of Greifswald; University of Bradford

The human epidermis holds an autocrine acetylcholine production and degradation including functioning membrane integrated and cytosolic butyrylcholinesterase (BuchE). Here we show that BuchE activities increase 9-fold in the presence of calcium (0.5 x 10{sup -3}M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. {sup 45}Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H{sub 2}O{sub 2}-mediated oxidation. Moreover, we confirmed the faster hydrolysis by calcium-activated BuchE using the neurotoxic organophosphate O-ethyl-O-(4-nitrophenyl)-phenylphosphonothioate (EPN). Considering the large size of the human skin with 1.8 m{sup 2} surfacemore » area with its calcium gradient in the 10{sup -3}M range, our results implicate calcium-activated BuchE as a major protective mechanism against suicide inhibition of AchE by organophosphates in this non-neuronal tissue.« less

Cardiogenic programming of human pluripotent stem cells by dose-controlled activation of EOMES.

PubMed

Pfeiffer, Martin J; Quaranta, Roberto; Piccini, Ilaria; Fell, Jakob; Rao, Jyoti; Röpke, Albrecht; Seebohm, Guiscard; Greber, Boris

2018-01-30

Master cell fate determinants are thought to induce specific cell lineages in gastrulation by orchestrating entire gene programs. The T-box transcription factor EOMES (eomesodermin) is crucially required for the development of the heart-yet it is equally important for endoderm specification suggesting that it may act in a context-dependent manner. Here, we define an unrecognized interplay between EOMES and the WNT signaling pathway in controlling cardiac induction by using loss and gain-of-function approaches in human embryonic stem cells. Dose-dependent EOMES induction alone can fully replace a cocktail of signaling molecules otherwise essential for the specification of cardiogenic mesoderm. Highly efficient cardiomyocyte programming by EOMES mechanistically involves autocrine activation of canonical WNT signaling via the WNT3 ligand, which necessitates a shutdown of this axis at a subsequent stage. Our findings provide insights into human germ layer induction and bear biotechnological potential for the robust production of cardiomyocytes from engineered stem cells.

5-Lipoxygenase Pathway, Dendritic Cells, and Adaptive Immunity

PubMed Central

Hedi, Harizi

2004-01-01

5-lipoxygenase (5-LO) pathway is the major source of potent proinflammatory leukotrienes (LTs) issued from the metabolism of arachidonic acid (AA), and best known for their roles in the pathogenesis of asthma. These lipid mediators are mainly released from myeloid cells and may act as physiological autocrine and paracrine signalling molecules, and play a central role in regulating the interaction between innate and adaptive immunity. The biological actions of LTs including their immunoregulatory and proinflammatory effects are mediated through extracellular specific G-protein-coupled receptors. Despite their role in inflammatory cells, such as neutrophils and macrophages, LTs may have important effects on dendritic cells (DC)-mediated adaptive immunity. Several lines of evidence show that DC not only are important source of LTs, but also become targets of their actions by producing other lipid mediators and proinflammatory molecules. This review focuses on advances in 5-LO pathway biology, the production of LTs from DC and their role on various cells of immune system and in adaptive immunity. PMID:15240920

PMA Induces SnoN Proteolysis and CD61 Expression through an Autocrine Mechanism

PubMed Central

Li, Chonghua; Peart, Natoya; Xuan, Zhenyu; Lewis, Dorothy E; Xia, Yang; Jin, Jianping

2014-01-01

Phorbol-12-myristate-13-acetate, also called PMA, is a small molecule that activates protein kinase C and functions to differentiate hematologic lineage cells. However, the mechanism of PMA-induced cellular differentiation is not fully understood. We found that PMA triggers global enhancement of protein ubiquitination in K562, a myelogenous leukemia cell line and one of the enhanced-ubiquitination targets is SnoN, an inhibitor of the Smad signaling pathway. Our data indicated that PMA stimulated the production of Activin A, a cytokine of the TGF-β family. Activin A then activated the phosphorylation of both Smad2 and Smad3. In consequence, SnoN is ubiquitinated by the APCCdh1 ubiquitin ligase with the help of phosphorylated Smad2. Furthermore, we found that SnoN proteolysis is important for the expression of CD61, a marker of megakaryocyte. These results indicate that protein ubiquitination promotes megakaryopoiesis via degrading SnoN, an inhibitor of CD61 expression, strengths the roles of ubiquitination in cellular differentiation. PMID:24637302

Physiological and physiopathological aspects of connexins and communicating gap junctions in spermatogenesis

PubMed Central

Pointis, Georges; Gilleron, Jérome; Carette, Diane; Segretain, Dominique

2010-01-01

Spermatogenesis is a highly regulated process of germ cell proliferation and differentiation, starting from spermatogonia to spermatocytes and giving rise to spermatids, the future spermatozoa. In addition to endocrine regulation, testicular cell–cell interactions are essential for spermatogenesis. This precise control is mediated through paracrine/autocrine pathways, direct intercellular contacts and through intercellular communication channels, consisting of gap junctions and their constitutive proteins, the connexins. Gap junctions are localized between adjacent Leydig cells, between Sertoli cells and between Sertoli cells and specific germ cells. This review focuses on the distribution of connexins within the seminiferous epithelium, their participation in gap junction channel formation, the control of their expression and the physiological relevance of these junctions in both the Sertoli–Sertoli cell functional synchronization and the Sertoli–germ cell dialogue. In this review, we also discuss the potential implication of disrupted connexin in testis cancer, since impaired expression of connexin has been described as a typical feature of tumoral proliferation. PMID:20403873

Cytokines and pulmonary fibrosis.

PubMed Central

Gauldie, J.; Jordana, M.; Cox, G.

1993-01-01

Chronically inflamed and fibrotic tissue of the respiratory tract can be shown to actively express the genes and products of a number of powerful growth and differentiating factors. The initial activation of lung inflammatory cells, including alveolar macrophages, is presumed to result in the release of early acting cytokines such as IL-1 and TNF. Subsequent activation and possible phenotype alteration of the structural cells results in release of other growth factors and accumulation of blood derived inflammatory cells. These cells, once they have entered the tissue and become further activated, may begin to release their own autocrine factors and "feed back" some of the similar signals to the tissue cells in a paracrine manner, further inducing differentiation and phenotype change. These internal tissue cell and cytokine cascades could account for the chronic nature of the inflammation. Therapeutic intervention must therefore take into account the inflammatory component as well as the nature of the cytokines and structural cells involved in the propagation of the disease. PMID:8236078

Regulation of CaV2 calcium channels by G protein coupled receptors

PubMed Central

Zamponi, Gerald W.; Currie, Kevin P.M.

2012-01-01

Voltage gated calcium channels (Ca2+ channels) are key mediators of depolarization induced calcium influx into excitable cells, and thereby play pivotal roles in a wide array of physiological responses. This review focuses on the inhibition of CaV2 (N- and P/Q-type) Ca2+-channels by G protein coupled receptors (GPCRs), which exerts important autocrine/paracrine control over synaptic transmission and neuroendocrine secretion. Voltage-dependent inhibition is the most widespread mechanism, and involves direct binding of the G protein βγ dimer (Gβγ) to the α1 subunit of CaV2 channels. GPCRs can also recruit several other distinct mechanisms including phosphorylation, lipid signaling pathways, and channel trafficking that result in voltage-independent inhibition. Current knowledge of Gβγ-mediated inhibition is reviewed, including the molecular interactions involved, determinants of voltage-dependence, and crosstalk with other cell signaling pathways. A summary of recent developments in understanding the voltage-independent mechanisms prominent in sympathetic and sensory neurons is also included. PMID:23063655

Axonal GABAA receptors.

PubMed

Trigo, Federico F; Marty, Alain; Stell, Brandon M

2008-09-01

Type A GABA receptors (GABA(A)Rs) are well established as the main inhibitory receptors in the mature mammalian forebrain. In recent years, evidence has accumulated showing that GABA(A)Rs are prevalent not only in the somatodendritic compartment of CNS neurons, but also in their axonal compartment. Evidence for axonal GABA(A)Rs includes new immunohistochemical and immunogold data: direct recording from single axonal terminals; and effects of local applications of GABA(A)R modulators on action potential generation, on axonal calcium signalling, and on neurotransmitter release. Strikingly, whereas presynaptic GABA(A)Rs have long been considered inhibitory, the new studies in the mammalian brain mostly indicate an excitatory action. Depending on the neuron that is under study, axonal GABA(A)Rs can be activated by ambient GABA, by GABA spillover, or by an autocrine action, to increase either action potential firing and/or transmitter release. In certain neurons, the excitatory effects of axonal GABA(A)Rs persist into adulthood. Altogether, axonal GABA(A)Rs appear as potent neuronal modulators of the mammalian CNS.

Downregulation of Ras C-terminal processing by JNK inhibition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mouri, Wataru; Department of Neurosurgery, Yamagata University School of Medicine, Yamagata 990-9585; Biology Division, National Cancer Center Research Institute, Tokyo 104-0045

2008-06-27

After translation, Ras proteins undergo a series of modifications at their C-termini. This post-translational C-terminal processing is essential for Ras to become functional, but it remains unknown whether and how Ras C-terminal processing is regulated. Here we show that the C-terminal processing and subsequent plasma membrane localization of H-Ras as well as the activation of the downstream signaling pathways by H-Ras are prevented by JNK inhibition. Conversely, JNK activation by ultraviolet irradiation resulted in promotion of C-terminal processing of H-Ras. Furthermore, increased cell density promoted C-terminal processing of H-Ras most likely through an autocrine/paracrine mechanism, which was also blocked undermore » JNK-inhibited condition. Ras C-terminal processing was sensitive to JNK inhibition in the case of H- and N-Ras but not K-Ras, and in a variety of cell types. Thus, our results suggest for the first time that Ras C-terminal processing is a regulated mechanism in which JNK is involved.« less

Corneal endothelial autocrine trophic factor VIP in a mechanism-based strategy to enhance human donor cornea preservation for transplantation.

PubMed

Koh, Shay-Whey Margaret

2012-02-01

Vasoactive intestinal peptide (VIP) and ciliary neurotrophic factor (CNTF) are identified as autocrines of human corneal endothelial (CE) cells working in concert to maintain the differentiated state and promote the survival of the corneal endothelium. From VIP gene knockdown study, endogenous VIP is shown to maintain the level of the differentiation marker, the adhesion molecule N-cadherin, CE cell size, shape, and retention, in situ in the human donor corneoscleral explants. Exogenous VIP protects the corneal endothelium against the killing effect of oxidative stress, in part by upholding ATP levels in CE cells dying of oxidative stress-induced injury, allowing them to die of an apoptotic death instead of an acute necrotic one. The switch from the acute necrosis to the programmed cell death (apoptosis) may have allowed the injured CE cell to be rescued by the VIP-upregulated pathways, including those of Bcl-2 and N-cadherin, and resulted in long-term CE cell survival. The endogenous VIP in CE cells is upregulated by CNTF, which is released by CE cells surviving the oxidative stress. The CNTF receptor (CNTFRα) is expressed in CE cells in human donor corneoscleral explant and gradually becomes lost during corneal storage. VIP treatment (10(-8) M, 37 °C, 30 min) prior to storage of freshly dissected human donor corneoscleral explants increases their CE cell CNTFRα level and responsiveness to CNTF in upregulating the gap junctional protein connexin-43 expression. VIP treatment of both fresh and preserved corneoscleral explants reduces CE damage in the corneoscleral explants and in the corneal buttons trephined from them. CE cell loss is a critical risk factor in corneal graft failure at any time in the life of the graft, which can be as late as 5-10 years after an initially successful transplant. A new procedure, Descemet's stripping automated endothelial keratoplasty (DSAEK), which is superior to the traditional full thickness transplantation in many aspects, nevertheless subjects the corneal endothelium to extensive mechanical forces, resulting in even more pronounced CE cell loss than the traditional technique. Whereas it is known that cells transduce mechanical stress through N-cadherin, stimulation of the N-cadherin pathway increases the anti-apoptotic protein Bcl-2 expression. Since N-cadherin and Bcl-2 in the corneal endothelium are both upregulated by VIP, we aim to strengthen the CE sheet by VIP treatments of the corneoscleral explants for full thickness traditional corneal transplantation and pre-cut corneas for DSAEK. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ghrelin O-acyltransferase (GOAT) is expressed in prostate cancer tissues and cell lines and expression is differentially regulated in vitro by ghrelin

PubMed Central

2013-01-01

Background Ghrelin is a 28 amino acid peptide hormone that is expressed in the stomach and a range of peripheral tissues, where it frequently acts as an autocrine/paracrine growth factor. Ghrelin is modified by a unique acylation required for it to activate its cognate receptor, the growth hormone secretagogue receptor (GHSR), which mediates many of the actions of ghrelin. Recently, the enzyme responsible for adding the fatty acid residue (octanoyl/acyl group) to the third amino acid of ghrelin, GOAT (ghrelin O-acyltransferase), was identified. Methods We used cell culture, quantitative real-time reverse transcription (RT)-PCR and immunohistochemistry to demonstrate the expression of GOAT in prostate cancer cell lines and tissues from patients. Real-time RT-PCR was used to demonstrate the expression of prohormone convertase (PC)1/3, PC2 and furin in prostate cancer cell lines. Prostate-derived cell lines were treated with ghrelin and desacyl ghrelin and the effect on GOAT expression was measured using quantitative RT-PCR. Results We have demonstrated that GOAT mRNA and protein are expressed in the normal prostate and human prostate cancer tissue samples. The RWPE-1 and RWPE-2 normal prostate-derived cell lines and the LNCaP, DU145, and PC3 prostate cancer cell lines express GOAT and at least one other enzyme that is necessary to produce mature, acylated ghrelin from proghrelin (PC1/3, PC2 or furin). Finally, ghrelin, but not desacyl ghrelin (unacylated ghrelin), can directly regulate the expression of GOAT in the RWPE-1 normal prostate derived cell line and the PC3 prostate cancer cell line. Ghrelin treatment (100nM) for 6 hours significantly decreased GOAT mRNA expression two-fold (P < 0.05) in the PC3 prostate cancer cell line, however, ghrelin did not regulate GOAT expression in the DU145 and LNCaP prostate cancer cell lines. Conclusions This study demonstrates that GOAT is expressed in prostate cancer specimens and cell lines. Ghrelin regulates GOAT expression, however, this is likely to be cell-type specific. The expression of GOAT in prostate cancer supports the hypothesis that the ghrelin axis has autocrine/paracrine roles. We propose that the RWPE-1 prostate cell line and the PC3 prostate cancer cell line may be useful for investigating GOAT regulation and function. PMID:23879975

The synthetic peptide P111-136 derived from the C-terminal domain of heparin affin regulatory peptide inhibits tumour growth of prostate cancer PC-3 cells

PubMed Central

2011-01-01

Background Heparin affin regulatory peptide (HARP), also called pleiotrophin, is a heparin-binding, secreted factor that is overexpressed in several tumours and associated to tumour growth, angiogenesis and metastasis. The C-terminus part of HARP composed of amino acids 111 to 136 is particularly involved in its biological activities and we previously established that a synthetic peptide composed of the same amino acids (P111-136) was capable of inhibiting the biological activities of HARP. Here we evaluate the ability of P111-136 to inhibit in vitro and in vivo the growth of a human tumour cell line PC-3 which possess an HARP autocrine loop. Methods A total lysate of PC-3 cells was incubated with biotinylated P111-136 and pulled down for the presence of the HARP receptors in Western blot. In vitro, the P111-136 effect on HARP autocrine loop in PC-3 cells was determined by colony formation in soft agar. In vivo, PC-3 cells were inoculated in the flank of athymic nude mice. Animals were treated with P111-136 (5 mg/kg/day) for 25 days. Tumour volume was evaluated during the treatment. After the animal sacrifice, the tumour apoptosis and associated angiogenesis were evaluated by immunohistochemistry. In vivo anti-angiogenic effect was confirmed using a mouse Matrigel™ plug assay. Results Using pull down experiments, we identified the HARP receptors RPTPβ/ζ, ALK and nucleolin as P111-136 binding proteins. In vitro, P111-136 inhibits dose-dependently PC-3 cell colony formation. Treatment with P111-136 inhibits significantly the PC-3 tumour growth in the xenograft model as well as tumour angiogenesis. The angiostatic effect of P111-136 on HARP was also confirmed using an in vivo Matrigel™ plug assay in mice Conclusions Our results demonstrate that P111-136 strongly inhibits the mitogenic effect of HARP on in vitro and in vivo growth of PC-3 cells. This inhibition could be linked to a direct or indirect binding of this peptide to the HARP receptors (ALK, RPTPβ/ζ, nucleolin). In vivo, the P111-136 treatment significantly inhibits both the PC-3 tumour growth and the associated angiogenesis. Thus, P111-136 may be considered as an interesting pharmacological tool to interfere with tumour growth that has now to be evaluated in other cancer types. PMID:21624116

Nesfatin-1-regulated oxytocinergic signaling in the paraventricular nucleus causes anorexia through a leptin-independent melanocortin pathway.

PubMed

Maejima, Yuko; Sedbazar, Udval; Suyama, Shigetomo; Kohno, Daisuke; Onaka, Tatsushi; Takano, Eisuke; Yoshida, Natsu; Koike, Masato; Uchiyama, Yasuo; Fujiwara, Ken; Yashiro, Takashi; Horvath, Tamas L; Dietrich, Marcelo O; Tanaka, Shigeyasu; Dezaki, Katsuya; Oh-I, Shinsuke; Hashimoto, Koushi; Shimizu, Hiroyuki; Nakata, Masanori; Mori, Masatomo; Yada, Toshihiko

2009-11-01

The hypothalamic paraventricular nucleus (PVN) functions as a center to integrate various neuronal activities for regulating feeding behavior. Nesfatin-1, a recently discovered anorectic molecule, is localized in the PVN. However, the anorectic neural pathway of nesfatin-1 remains unknown. Here we show that central injection of nesfatin-1 activates the PVN and brain stem nucleus tractus solitarius (NTS). In the PVN, nesfatin-1 targets both magnocellular and parvocellular oxytocin neurons and nesfatin-1 neurons themselves and stimulates oxytocin release. Immunoelectron micrographs reveal nesfatin-1 specifically in the secretory vesicles of PVN neurons, and immunoneutralization against endogenous nesfatin-1 suppresses oxytocin release in the PVN, suggesting paracrine/autocrine actions of nesfatin-1. Nesfatin-1-induced anorexia is abolished by an oxytocin receptor antagonist. Moreover, oxytocin terminals are closely associated with and oxytocin activates pro-opiomelanocortin neurons in the NTS. Oxytocin induces melanocortin-dependent anorexia in leptin-resistant Zucker-fatty rats. The present results reveal the nesfatin-1-operative oxytocinergic signaling in the PVN that triggers leptin-independent melanocortin-mediated anorexia.

Tumor Microenvironment Modulation via Gold Nanoparticles Targeting Malicious Exosomes: Implications for Cancer Diagnostics and Therapy

PubMed Central

Roma-Rodrigues, Catarina; Raposo, Luís R.; Cabral, Rita; Paradinha, Fabiana; Baptista, Pedro V.; Fernandes, Alexandra R.

2017-01-01

Exosomes are nanovesicles formed in the endosomal pathway with an important role in paracrine and autocrine cell communication. Exosomes secreted by cancer cells, malicious exosomes, have important roles in tumor microenvironment maturation and cancer progression. The knowledge of the role of exosomes in tumorigenesis prompted a new era in cancer diagnostics and therapy, taking advantage of the use of circulating exosomes as tumor biomarkers due to their stability in body fluids and targeting malignant exosomes’ release and/or uptake to inhibit or delay tumor development. In recent years, nanotechnology has paved the way for the development of a plethora of new diagnostic and therapeutic platforms, fostering theranostics. The unique physical and chemical properties of gold nanoparticles (AuNPs) make them suitable vehicles to pursuit this goal. AuNPs’ properties such as ease of synthesis with the desired shape and size, high surface:volume ratio, and the possibility of engineering their surface as desired, potentiate AuNPs’ role in nanotheranostics, allowing the use of the same formulation for exosome detection and restraining the effect of malicious exosomes in cancer progression. PMID:28098821

G protein-coupled receptor kinase 2 positively regulates epithelial cell migration

PubMed Central

Penela, Petronila; Ribas, Catalina; Aymerich, Ivette; Eijkelkamp, Niels; Barreiro, Olga; Heijnen, Cobi J; Kavelaars, Annemieke; Sánchez-Madrid, Francisco; Mayor, Federico

2008-01-01

Cell migration requires integration of signals arising from both the extracellular matrix and messengers acting through G protein-coupled receptors (GPCRs). We find that increased levels of G protein-coupled receptor kinase 2 (GRK2), a key player in GPCR regulation, potentiate migration of epithelial cells towards fibronectin, whereas such process is decreased in embryonic fibroblasts from hemizygous GRK2 mice or upon knockdown of GRK2 expression. Interestingly, the GRK2 effect on fibronectin-mediated cell migration involves the paracrine/autocrine activation of a sphingosine-1-phosphate (S1P) Gi-coupled GPCR. GRK2 positively modulates the activity of the Rac/PAK/MEK/ERK pathway in response to adhesion and S1P by a mechanism involving the phosphorylation-dependent, dynamic interaction of GRK2 with GIT1, a key scaffolding protein in cell migration processes. Furthermore, decreased GRK2 levels in hemizygous mice result in delayed wound healing rate in vivo, consistent with a physiological role of GRK2 as a regulator of coordinated integrin and GPCR-directed epithelial cell migration. PMID:18369319

Effects of ANP receptor antagonists on ANP secretion from adult rat cultured atrial myocytes.

PubMed

Nachshon, S; Zamir, O; Matsuda, Y; Zamir, N

1995-03-01

Atrial natriuretic peptide (ANP) is a hormone-secreted predominantly by atrial myocytes. ANP exerts many of its actions via activation of the particulate guanylyl cyclase receptor ANPR-A and the formation of guanosine 3',5'-cyclic monophosphate (cGMP), which serves as a second messenger in the target cells. Using membrane-permeable cGMP analogues (8-bromo-cGMP and dibutyryl- cGMP), we first tested the hypothesis that ANP secretion by adult rat cultured atrial myocytes can be modulated through the second messenger cGMP. Second, we examined the effects of two competitive ANPR-A receptor antagonists, namely HS-142-1 and anantin, on cGMP formation and ANP secretion from cultured atrial myocytes. Cultured atrial myocytes secreted large quantities of immunoreactive (ir) ANP under basal conditions. We found that cGMP analogues inhibited basal irANP secretion from cultured atrial myocytes, whereas HS-142-1 and anantin had stimulating effects. HS-142-1 and anantin reduced cGMP formation in cultured atrial myocytes at basal conditions. These results suggest an autoregulatory mechanism of ANP secretion by atrial myocytes in an autocrine/paracrine fashion.

Endocannabinoids and the Immune System in Health and Disease.

PubMed

Cabral, Guy A; Ferreira, Gabriela A; Jamerson, Melissa J

2015-01-01

Endocannabinoids are bioactive lipids that have the potential to signal through cannabinoid receptors to modulate the functional activities of a variety of immune cells. Their activation of these seven-transmembranal, G protein-coupled receptors sets in motion a series of signal transductional events that converge at the transcriptional level to regulate cell migration and the production of cytokines and chemokines. There is a large body of data that supports a functional relevance for 2-arachidonoylglycerol (2-AG) as acting through the cannabinoid receptor type 2 (CB2R) to inhibit migratory activities for a diverse array of immune cell types. However, unequivocal data that supports a functional linkage of anandamide (AEA) to a cannabinoid receptor in immune modulation remains to be obtained. Endocannabinoids, as typical bioactive lipids, have a short half-life and appear to act in an autocrine and paracrine fashion. Their immediate effective action on immune function may be at localized sites in the periphery and within the central nervous system. It is speculated that endocannabinoids play an important role in maintaining the overall "fine-tuning" of the immune homeostatic balance within the host.

Growth hormone and Pit-1 expression in bovine fetal lymphoid cells.

PubMed

Chen, H T; Schuler, L A; Schultz, R D

1997-11-01

Bovine fetal lymphoid cells were examined for growth hormone (GH) and the transcription factor Pit-1/GHF-1 mRNA. GH and Pit-1/GHF-1 transcripts were detected in thymocytes and splenocytes from fetuses at 60, 90, 120, and 270 d of gestation using reverse transcription-polymerase chain reaction (RT-PCR). Northern analysis indicated that the lymphoid GH mRNA was approximately 350 nucleotides larger than in the pituitary. RT-PCR analysis demonstrated that the coding regions as well as 3' untranslated region of the lymphocyte GH and pituitary transcripts were the same. Analysis of the 5'-untranslated region of the lymphocyte GH mRNA showed that transcription began upstream from the start site in the pituitary gland, suggesting differences in regulation in these tissues. Fetal thymocytes and splenocytes expressed Pit-1/GHF-1 mRNA; however, they contained only the 2.5-kb transcript. The GH and Pit-1/GHF-1 mRNA in fetal lymphoid cells supports the hypothesis that lymphocyte-derived GH may function as an autocrine and/or paracrine factor during the development and maturation of the bovine fetal immune system.

Implications of adiponectin in linking metabolism to testicular function.

PubMed

Martin, Luc J

2014-05-01

Obesity is a major health problem, contributing to the development of various diseases with aging. In humans, obesity has been associated with reduced testosterone production and subfertility. Adipose tissue is an important source of hormones having influences on both metabolism and reproduction. Among them, the production and secretion of adiponectin is inversely correlated to the severity of obesity. The purpose of this review of literature is to present the current state of knowledge on adiponectin research to determine whether this hormone affects reproduction in men. Surprisingly, evidences show negative influences of adiponectin on GnRH secretion from the hypothalamus, LH and FSH secretion from the pituitary and testosterone at the testicular level. Thus far, the involvement of adiponectin in the influence of metabolism on reproduction in men is limited. However, adiponectin and its receptors are expressed by different cell types of the male gonad, including Leydig cells, spermatozoa, and epididymis. In addition, actions of adiponectin at the testicular level have been shown to promote spermatogenesis and sperm maturation. Therefore, autocrine/paracrine actions of adiponectin in the testis may contribute to support male reproductive function.

The Endocannabinoid System and Spermatogenesis

PubMed Central

Grimaldi, Paola; Di Giacomo, Daniele; Geremia, Raffaele

2013-01-01

Spermatogenesis is a complex process in which male germ cells undergo a mitotic phase followed by meiosis and by a morphogenetic process to form mature spermatozoa. Spermatogenesis is under the control of gonadotropins, steroid hormones and it is modulated by a complex network of autocrine and paracrine factors. These modulators ensure the correct progression of germ cell differentiation to form mature spermatozoa. Recently, it has been pointed out the relevance of endocannabinoids as critical modulators of male reproduction. Endocannabinoids are natural lipids able to bind to cannabinoid receptors and whose levels are regulated by specific biosynthetic and degradative enzymes. Together with their receptors and metabolic enzymes, they form the “endocannabinoid system” (ECS). In male reproductive tracts, they affect Sertoli cell activities, Leydig cell proliferation, germ cell differentiation, sperm motility, capacitation, and acrosome reaction. The ECS interferes with the pituitary-gonadal axis, and an intricate crosstalk between ECS and steroid hormones has been highlighted. This mini-review will focus on the involvement of the ECS in the control of spermatogenesis and on the interaction between ECS and steroid hormones. PMID:24379805

Polyubiquitylation of AMF requires cooperation between the gp78 and TRIM25 ubiquitin ligases.

PubMed

Wang, Ying; Ha, Seung-Wook; Zhang, Tianpeng; Kho, Dhong-Hyo; Raz, Avraham; Xie, Youming

2014-04-30

gp78 is a ubiquitin ligase that plays a vital role in endoplasmic reticulum (ER)-associated degradation (ERAD). Here we report that autocrine motility factor (AMF), also known as phosphoglucose isomerase (PGI), is a novel substrate of gp78. We show that polyubiquitylation of AMF requires cooperative interaction between gp78 and the ubiquitin ligase TRIM25 (tripartite motif-containing protein 25). While TRIM25 mediates the initial round of ubiquitylation, gp78 catalyzes polyubiquitylation of AMF. The E4-like activity of gp78 was illustrated by an in vitro polyubiquitylation assay using Ub-DHFR as a model substrate. We further demonstrate that TRIM25 ubiquitylates gp78 and that overexpression of TRIM25 accelerates the degradation of gp78. Our data suggest that TRIM25 not only cooperates with gp78 in polyubiquitylation of AMF but also gauges the steady-state level of gp78. This study uncovers a previously unknown functional link between gp78 and TRIM25 and provides mechanistic insight into gp78-mediated protein ubiquitylation.

Polyubiquitylation of AMF requires cooperation between the gp78 and TRIM25 ubiquitin ligases

PubMed Central

Kho, Dhong-Hyo; Raz, Avraham; Xie, Youming

2014-01-01

gp78 is a ubiquitin ligase that plays a vital role in endoplasmic reticulum (ER)-associated degradation (ERAD). Here we report that autocrine motility factor (AMF), also known as phosphoglucose isomerase (PGI), is a novel substrate of gp78. We show that polyubiquitylation of AMF requires cooperative interaction between gp78 and the ubiquitin ligase TRIM25 (tripartite motif-containing protein 25). While TRIM25 mediates the initial round of ubiquitylation, gp78 catalyzes polyubiquitylation of AMF. The E4-like activity of gp78 was illustrated by an in vitro polyubiquitylation assay using Ub-DHFR as a model substrate. We further demonstrate that TRIM25 ubiquitylates gp78 and that overexpression of TRIM25 accelerates the degradation of gp78. Our data suggest that TRIM25 not only cooperates with gp78 in polyubiquitylation of AMF but also gauges the steady-state level of gp78. This study uncovers a previously unknown functional link between gp78 and TRIM25 and provides mechanistic insight into gp78-mediated protein ubiquitylation. PMID:24810856

Biology and biotechnology of follicle development.

PubMed

Palma, Gustavo Adolfo; Argañaraz, Martin Eduardo; Barrera, Antonio Daniel; Rodler, Daniela; Mutto, Adrian Ángel; Sinowatz, Fred

2012-01-01

Growth and development of ovarian follicles require a series of coordinated events that induce morphological and functional changes within the follicle, leading to cell differentiation and oocyte development. The preantral early antral follicle transition is the stage of follicular development during which gonadotropin dependence is obtained and the progression into growing or atresia of the follicle is made. Follicular growth during this period is tightly regulated by oocyte-granulosatheca cell interactions. A cluster of early expressed genes is required for normal folliculogenesis. Granulosa cell factors stimulate the recruitment of theca cells from cortical stromal cells. Thecal factors promote granulosa cell proliferation and suppress granulosa cell apoptosis. Cell-cell and cell-extracellular matrix interactions influence the production of growth factors in the different follicular compartments (oocyte, granulosa, and theca cells). Several autocrine and paracrine factors are involved in follicular growth and differentiation; their activity is present even at the time of ovulation, decreasing the gap junction communication, and stimulating the theca cell proliferation. In addition, the identification of the factors that promote follicular growth from the preantral stage to the small antral stage may provide important information for the identification for assisted reproduction techniques.

Toll-like Receptor 2: A Novel Therapeutic Target for Ischemic White Matter Injury and Oligodendrocyte Death

PubMed Central

Choi, Jun Young

2017-01-01

Despite paramount clinical significance of white matter stroke, there is a paucity of researches on the pathomechanism of ischemic white matter damage and accompanying oligodendrocyte (OL) death. Therefore, a large gap exists between clinical needs and laboratory researches in this disease entity. Recent works have started to elucidate cellular and molecular basis of white matter injury under ischemic stress. In this paper, we briefly introduce white matter stroke from a clinical point of view and review pathophysiology of ischemic white matter injury characterized by OL death and demyelination. We present a series of evidence that Toll-like receptor 2 (TLR2), one of the membranous pattern recognition receptors, plays a cell-autonomous protective role in ischemic OL death and ensuing demyelination. Moreover, we also discuss our recent findings that its endogenous ligand, high-mobility group box 1 (HMGB1), is released from dying OLs and exerts autocrine trophic effects on OLs and myelin sheath under ischemic condition. We propose that modulation of TLR2 and its endogenous ligand HMGB1 can be a novel therapeutic target for ischemic white matter disease. PMID:28912641

The physiology of a local renin-angiotensin system in the pancreas.

PubMed

Leung, Po Sing

2007-04-01

The systemic renin-angiotensin system (RAS) plays an important role in regulating blood pressure, electrolyte and fluid homeostasis. However, local RASs also exist in diverse tissues and organs, where they play a multitude of autocrine, paracrine and intracrine physiological roles. The existence of a local RAS is now recognized in pancreatic acinar, islet, duct, endothelial and stellate cells, the expression of which is modulated in response to physiological and pathophysiological stimuli such as hypoxia, pancreatitis, islet transplantation, hyperglycaemia, and diabetes mellitus. This pancreatic RAS has been proposed to have important endocrine and exocrine roles in the pancreas, regulating local blood flow, duct cell sodium bicarbonate secretion, acinar cell digestive enzyme secretion, islet beta-cell (pro)insulin biosynthesis, and thus, glucose-stimulated insulin release, delta-cell somatostatin secretion, and pancreatic cell proliferation and differentiation. It may further mediate oxidative stress-induced cell inflammation, apoptosis and fibrosis. Further exploration of this system would probably offer new insights into the pathogenesis of pancreatitis, diabetes, cystic fibrosis and pancreatic cancer formation. New therapeutic targets and strategies might thus be suggested.

The physiology of a local renin–angiotensin system in the pancreas

PubMed Central

Leung, Po Sing

2007-01-01

The systemic renin–angiotensin system (RAS) plays an important role in regulating blood pressure, electrolyte and fluid homeostasis. However, local RASs also exist in diverse tissues and organs, where they play a multitude of autocrine, paracrine and intracrine physiological roles. The existence of a local RAS is now recognized in pancreatic acinar, islet, duct, endothelial and stellate cells, the expression of which is modulated in response to physiological and pathophysiological stimuli such as hypoxia, pancreatitis, islet transplantation, hyperglycaemia, and diabetes mellitus. This pancreatic RAS has been proposed to have important endocrine and exocrine roles in the pancreas, regulating local blood flow, duct cell sodium bicarbonate secretion, acinar cell digestive enzyme secretion, islet beta-cell (pro)insulin biosynthesis, and thus, glucose-stimulated insulin release, delta-cell somatostatin secretion, and pancreatic cell proliferation and differentiation. It may further mediate oxidative stress-induced cell inflammation, apoptosis and fibrosis. Further exploration of this system would probably offer new insights into the pathogenesis of pancreatitis, diabetes, cystic fibrosis and pancreatic cancer formation. New therapeutic targets and strategies might thus be suggested. PMID:17218353

Protein B61 as a new growth factor: expression of B61 and up-regulation of its receptor epithelial cell kinase during melanoma progression.

PubMed

Easty, D J; Guthrie, B A; Maung, K; Farr, C J; Lindberg, R A; Toso, R J; Herlyn, M; Bennett, D C

1995-06-15

Epithelial cell kinase (ECK) is a receptor protein tyrosine kinase, the role of which in melanoma biology is unclear. Here we studied the role of ECK during melanoma progression. ECK mRNA was overexpressed in virtually all melanoma lines tested, and levels were significantly higher in cell lines from distant metastases than primary melanomas; melanocytes were negative. Gene amplification was not detected in melanomas. Levels of ECK protein corresponded well with mRNA levels. B61 or LERK-1, recently identified as an ECK ligand, stimulated the growth of ECK-expressing melanoma cell lines, its first identified biological activity. Melanoma chemotaxis and chemoinvasion were not affected by B61. Growth of normal melanocytes was not affected. mRNA for B61 was detected in both melanoma cell lines and normal melanocytes. B61 was also identified by Western blotting and ECK binding activity with the use of a BIAcore binding assay in melanoma cell-conditioned media. These results suggest that B61 is an autocrine growth factor for melanomas but not normal melanocytes.

cDNA cloning of an intracellular form of the human interleukin 1 receptor antagonist associated with epithelium.

PubMed Central

Haskill, S; Martin, G; Van Le, L; Morris, J; Peace, A; Bigler, C F; Jaffe, G J; Hammerberg, C; Sporn, S A; Fong, S

1991-01-01

A cDNA encoding a receptor antagonist of interleukin 1 (IL-1ra), secreted from human monocytes, has recently been isolated and sequenced [Eisenberg, S. P., Evans, R. J., Arend, W. P., Verderber, E., Brewer, M. T., Hannum, C. H. & Thompson, R. C. (1990) Nature (London) 343, 341-346]. We have identified another version of this IL-1ra, which is predominantly expressed in epithelial cells. This IL-1ra lacks a leader sequence and, thus, is probably intracellular. Both proteins are derived from the same gene through use of an alternative transcriptional start site and internal splice-acceptor site. Expression of intracellular IL-1ra cDNA in COS cells demonstrated that the intracellular product specifically inhibited exogenous interleukin 1-dependent responses. Keratinocytes were shown to contain significant amounts of nonsecreted IL-1ra protein. Constitutive expression of the intracellular IL-1ra may be an intracellular defensive mechanism in exposed epithelial cells and/or may serve to regulate autocrine interleukin 1-mediated pathways of differentiation. Images PMID:1827201

The Epidermal Growth Factor Receptor Promotes Glomerular Injury and Renal Failure in Rapidly Progressive Crescentic Glomerulonephritis; the Identification of Possible Therapy

PubMed Central

Bollée, Guillaume; Flamant, Martin; Schordan, Sandra; Fligny, Cécile; Rumpel, Elisabeth; Milon, Marine; Schordan, Eric; Sabaa, Nathalie; Vandermeersch, Sophie; Galaup, Ariane; Rodenas, Anita; Casal, Ibrahim; Sunnarborg, Susan W; Salant, David J; Kopp, Jeffrey B.; Threadgill, David W; Quaggin, Susan E; Dussaule, Jean-Claude; Germain, Stéphane; Mesnard, Laurent; Endlich, Karlhans; Boucheix, Claude; Belenfant, Xavier; Callard, Patrice; Endlich, Nicole; Tharaux, Pierre-Louis

2011-01-01

Rapidly progressive glomerulonephritis (RPGN) is a clinical a morphological expression of severe glomerular injury. Glomerular injury manifests as a proliferative histological pattern (“crescents”) with accumulation of T cells and macrophages, and proliferation of intrinsic glomerular cells. We show de novo induction of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in intrinsic glomerular epithelial cells (podocytes) from both mice and humans with RPGN. HB-EGF induction increases phosphorylation of the EGFR/ErbB1 receptor in mice with RPGN. In HB-EGF-deficient mice, EGFR activation in glomeruli is absent and the course of RPGN is improved. Autocrine HB-EGF induces a phenotypic switch in podocytes in vitro. Conditional deletion of the Egfr gene from podocytes of mice alleviates the severity of RPGN. Pharmacological blockade of EGFR also improves the course of RPGN, even when started 4 days after the induction of experimental RPGN. This suggests that targeting the HB-EGF/EGFR pathway could also be beneficial for treatment of human RPGN. PMID:21946538

Interleukins 1alpha and 1beta secreted by some melanoma cell lines strongly reduce expression of MITF-M and melanocyte differentiation antigens.

PubMed

Kholmanskikh, Olga; van Baren, Nicolas; Brasseur, Francis; Ottaviani, Sabrina; Vanacker, Julie; Arts, Nathalie; van der Bruggen, Pierre; Coulie, Pierre; De Plaen, Etienne

2010-10-01

We report that melanoma cell lines expressing the interleukin-1 receptor exhibit 4- to 10-fold lower levels of mRNA of microphthalmia-associated transcription factor (MITF-M) when treated with interleukin-1beta. This effect is NF-kappaB and JNK-dependent. MITF-M regulates the expression of melanocyte differentiation genes such as MLANA, tyrosinase and gp100, which encode antigens recognized on melanoma cells by autologous cytolytic T lymphocytes. Accordingly, treating some melanoma cells with IL-1beta reduced by 40-100% their ability to activate such antimelanoma cytolytic T lymphocytes. Finally, we observed large amounts of biologically active IL-1alpha or IL-1beta secreted by two melanoma cell lines that did not express MITF-M, suggesting an autocrine MITF-M downregulation. We estimate that approximately 13% of melanoma cell lines are MITF-M-negative and secrete IL-1 cytokines. These results indicate that the repression of melanocyte-differentiation genes by IL-1 produced by stromal cells or by tumor cells themselves may represent an additional mechanism of melanoma immune escape.

Epithelial–Mesenchymal Interactions as a Working Concept for Oral Mucosa Regeneration

PubMed Central

Liu, Jiarong

2011-01-01

Oral mucosa consists of two tissue layers, the superficial epithelium and the underlying lamina propria. Together, oral mucosa functions as a barrier against exogenous substances and pathogens. In development, interactions of stem/progenitor cells of the epithelium and mesenchyme are crucial to the morphogenesis of oral mucosa. Previous work in oral mucosa regeneration has yielded important clues for several meritorious proof-of-concept approaches. Tissue engineering offers a broad array of novel tools for oral mucosa regeneration with reduced donor site trauma and accelerated clinical translation. However, the developmental concept of epithelial–mesenchymal interactions (EMIs) is rarely considered in oral mucosa regeneration. EMIs in postnatal oral mucosa regeneration likely will not be a simple recapitulation of prenatal oral mucosa development. Biomaterial scaffolds play an indispensible role for oral mucosa regeneration and should provide a conducive environment for pivotal EMIs. Autocrine and paracrine factors, either exogenously delivered or innately produced, have rarely been and should be harnessed to promote oral mucosa regeneration. This review focuses on a working concept of epithelial and mesenchymal interactions in oral mucosa regeneration. PMID:21062224

Unsupported platinum nanoparticles as effective sensors of neurotransmitters and possible drug curriers

NASA Astrophysics Data System (ADS)

Tąta, Agnieszka; Gralec, Barbara; Proniewicz, Edyta

2018-03-01

Herein, surface-enhanced Raman scattering (SERS) activity of positively charged unsupported platinum nanoparticles (PtNPs) with ∼12 nm size and narrow size distribution, in an aqueous solution, towards neurotransmitters was monitored at 785 nm excitation wavelength. The pure PtNPs were synthetized by polyol method. Their morphology and structure were checked by scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD) measurements. As a neurotransmitter bombesin (BN), which exhibits autocrine effect on the growth of normal and tumour tissues, and its fragments from the C-terminal end: BN13-14, BN12-14, BN11-14, BN10-14, BN9-14, and BN8-14 (X-14 fragments of the BN amino acid sequence) were chosen. The collected spectra were interpreted and discussed. This is to determine the adsorption mode of bombesin onto the PtNPs surface and changes in this mode as a result of the bombesin backbone shortening from the N-terminal end. This is important from the point of using PtNPs as potential BN carrier into the cancerous tissue and antitumor drug.

Thalidomide prevents formation of multinucleated giant cells (Langhans-type cells) from cultured monocytes: possible pharmaceutical applications for granulomatous disorders.

PubMed

Yasui, K; Yashiro, M; Nagaoka, Y; Manki, A; Wada, T; Tsuge, M; Kondo, Y; Morishima, T

2009-01-01

Thalidomide is an effective drug for chronic inflammatory diseases, but the mechanism underlying its immunomodulatory action remains uncertain. Thalidomide has been reported to clinically improve chronic inflammatory granulomatous disorders. In such disorders, the granulomas consist of epithelioid cells, scattered lymphocytes and multinucleated giant cells (MNGC; Langhans-type cells). The present experimental approach permitted the reproduction of MNGC formation from peripheral blood monocytes and examination of thalidomides effect on it. MNGC can be effectively generated from monocytes cultured in the presence of interleukin-4 (IL-4) and macrophage colony-stimulating factor(M-CSF) for 14 days. Thalidomide can inhibit the formation of MNGC in a dose-dependent manner. MNGC formation was partly inhibited by the presence of neutralizing TNF-alpha antibody in the responses induced by IL-4 and M-CSF. Autocrinal TNF-alpha production and modulation of cadhelin expression to regulate cell adhesion might be involved in this inhibitory action of thalidomide. Our results support thalidomides clinical efficacy in the treatment of chronic granulomatous disorders (granulomatosis).

Natural Killer Cells Control Tumor Growth by Sensing a Growth Factor.

PubMed

Barrow, Alexander D; Edeling, Melissa A; Trifonov, Vladimir; Luo, Jingqin; Goyal, Piyush; Bohl, Benjamin; Bando, Jennifer K; Kim, Albert H; Walker, John; Andahazy, Mary; Bugatti, Mattia; Melocchi, Laura; Vermi, William; Fremont, Daved H; Cox, Sarah; Cella, Marina; Schmedt, Christian; Colonna, Marco

2018-01-25

Many tumors produce platelet-derived growth factor (PDGF)-DD, which promotes cellular proliferation, epithelial-mesenchymal transition, stromal reaction, and angiogenesis through autocrine and paracrine PDGFRβ signaling. By screening a secretome library, we found that the human immunoreceptor NKp44, encoded by NCR2 and expressed on natural killer (NK) cells and innate lymphoid cells, recognizes PDGF-DD. PDGF-DD engagement of NKp44 triggered NK cell secretion of interferon gamma (IFN)-γ and tumor necrosis factor alpha (TNF-α) that induced tumor cell growth arrest. A distinctive transcriptional signature of PDGF-DD-induced cytokines and the downregulation of tumor cell-cycle genes correlated with NCR2 expression and greater survival in glioblastoma. NKp44 expression in mouse NK cells controlled the dissemination of tumors expressing PDGF-DD more effectively than control mice, an effect enhanced by blockade of the inhibitory receptor CD96 or CpG-oligonucleotide treatment. Thus, while cancer cell production of PDGF-DD supports tumor growth and stromal reaction, it concomitantly activates innate immune responses to tumor expansion. Copyright © 2017 Elsevier Inc. All rights reserved.

Synaptic and paracrine mechanisms at carotid body arterial chemoreceptors

PubMed Central

Nurse, Colin A

2014-01-01

Mammalian carotid bodies are the main peripheral arterial chemoreceptors, strategically located at the bifurcation of the common carotid artery. When stimulated these receptors initiate compensatory respiratory and cardiovascular reflexes to maintain homeostasis. Thus, in response to low oxygen (hypoxia) or increased CO2/H+ (acid hypercapnia), chemoreceptor type I cells depolarize and release excitatory neurotransmitters, such as ATP, which stimulate postsynaptic P2X2/3 receptors on afferent nerve terminals. The afferent discharge is shaped by autocrine and paracrine mechanisms involving both excitatory and inhibitory neuromodulators such as adenosine, serotonin (5-HT), GABA and dopamine. Recent evidence suggests that paracrine activation of P2Y2 receptors on adjacent glia-like type II cells may help boost the ATP signal via the opening of pannexin-1 channels. The presence of an inhibitory efferent innervation, mediated by release of nitric oxide, provides additional control of the afferent discharge. The broad array of neuromodulators and their receptors appears to endow the carotid body with a remarkable plasticity, most apparent during natural and pathophysiological conditions associated with chronic sustained and intermittent hypoxia. PMID:24665097

Synaptic communication and signal processing among sensory cells in taste buds.

PubMed

Chaudhari, Nirupa

2014-08-15

Taste buds (sensory structures embedded in oral epithelium) show a remarkable diversity of transmitters synthesized and secreted locally. The known transmitters accumulate in a cell type selective manner, with 5-HT and noradrenaline being limited to presynaptic cells, GABA being synthesized in both presynaptic and glial-like cells, and acetylcholine and ATP used for signalling by receptor cells. Each of these transmitters participates in local negative or positive feedback circuits that target particular cell types. Overall, the role of ATP is the best elucidated. ATP serves as a principal afferent transmitter, and also is the key trigger for autocrine positive feedback and paracrine circuits that result in potentiation (via adenosine) or inhibition (via GABA or 5-HT). While many of the cellular receptors and mechanisms for these circuits are known, their impact on sensory detection and perception remains to be elaborated in most instances. This brief review examines what is known, and some of the open questions and controversies surrounding the transmitters and circuits of the taste periphery. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

A murine model of acute myeloid leukemia with Evi1 overexpression and autocrine stimulation by an intracellular form of GM-CSF in DA-3 cells.

PubMed

Cardona, Maria E; Simonson, Oscar E; Oprea, Iulian I; Moreno, Pedro M D; Silva-Lara, Maria F; Mohamed, Abdalla J; Christensson, Birger; Gahrton, Gösta; Dilber, M Sirac; Smith, C I Edvard; Arteaga, H Jose

2016-01-01

The poor treatment response of acute myeloid leukemia (AML) overexpressing high-risk oncogenes such as EVI1, demands specific animal models for new treatment evaluations. Evi1 is a common site of activating integrations in murine leukemia virus (MLV)-induced AML and in retroviral and lentiviral gene-modified HCS. Still, a model of overt AML induced by Evi1 has not been generated. Cell lines from MLV-induced AML are growth factor-dependent and non-transplantable. Hence, for the leukemia maintenance in the infected animals, a growth factor source such as chronic immune response has been suggested. We have investigated whether these leukemias are transplantable if provided with growth factors. We show that the Evi1(+)DA-3 cells modified to express an intracellular form of GM-CSF, acquired growth factor independence and transplantability and caused an overt leukemia in syngeneic hosts, without increasing serum GM-CSF levels. We propose this as a general approach for modeling different forms of high-risk human AML using similar cell lines.

Inhibin at 90: From Discovery to Clinical Application, a Historical Review

PubMed Central

Makanji, Yogeshwar; Zhu, Jie; Mishra, Rama; Holmquist, Chris; Wong, Winifred P. S.; Schwartz, Neena B.; Mayo, Kelly E.

2014-01-01

When it was initially discovered in 1923, inhibin was characterized as a hypophysiotropic hormone that acts on pituitary cells to regulate pituitary hormone secretion. Ninety years later, what we know about inhibin stretches far beyond its well-established capacity to inhibit activin signaling and suppress pituitary FSH production. Inhibin is one of the major reproductive hormones involved in the regulation of folliculogenesis and steroidogenesis. Although the physiological role of inhibin as an activin antagonist in other organ systems is not as well defined as it is in the pituitary-gonadal axis, inhibin also modulates biological processes in other organs through paracrine, autocrine, and/or endocrine mechanisms. Inhibin and components of its signaling pathway are expressed in many organs. Diagnostically, inhibin is used for prenatal screening of Down syndrome as part of the quadruple test and as a biochemical marker in the assessment of ovarian reserve. In this review, we provide a comprehensive summary of our current understanding of the biological role of inhibin, its relationship with activin, its signaling mechanisms, and its potential value as a diagnostic marker for reproductive function and pregnancy-associated conditions. PMID:25051334

[Neuroendocrine immunomodulation].

PubMed

Uchakin, P N; Uchakina, O N; Tobin, B V; Ershov, F I

2007-01-01

Close interaction between the immune and nervous systems is well documented. The ability of immunocompetent cells to express receptors to neuroendocrine mediators as well as secrete many of them is proved. The current literature suggests that the hormones of the hypothalamic-pituitary-adrenal and the hypothalamic-pituitary-gonodal axes play the most significant role in the regulation of immune responsiveness. On the other hand, the immune system communicates with the CNS directly through the cytokines that are able to cross the blood-brain barrier, or directly via the nervus vagus, as well as via secondary messengers. Receptors to a number of cytokines have been found in the nervous tissue. Moreover, glial cells are able to secrete cytokines in the amount significant enough for at least autocrine action. In this article, the authors review the role of the "major" stress hormones such as cortisol, DHEA, growth hormone in the regulation of immune response, as well as neuro- and psychotropic properties of two major groups of cytokines that support cell-mediated (Type 1) and humoral (Type 2) immune reactions. This review emphasizes neuro-endocrine-immune interactions in response to infection both under laboratory and clinical conditions.

Enforced expression of KDR receptor promotes proliferation, survival and megakaryocytic differentiation of TF1 progenitor cell line.

PubMed

Coppola, S; Narciso, L; Feccia, T; Bonci, D; Calabrò, L; Morsilli, O; Gabbianelli, M; De Maria, R; Testa, U; Peschle, C

2006-01-01

Vascular endothelial growth factor (VEGF) receptor-2/kinase insert domain-containing receptor (KDR) is expressed in primitive hematopoietic cells, in megakaryocytes and platelets. In primitive hematopoiesis KDR mediates cell survival via autocrine VEGF, while its effect on cell growth and differentiation has not been elucidated. We induced enforced KDR expression in the granulocyte macrophage-colony-stimulating factor (GM-CSF)-dependent TF1 progenitor cell line (TF1-KDR), treated the cells with VEGF and analyzed their response. In GM-CSF-deprived cells, VEGF induces cell proliferation and protection against apoptosis, followed by enhanced expression of megakaryocytic (MK) markers. Combined with GM-CSF, VEGF induces a mild proliferative stimulus, followed by cell adherence, accumulation in G0/G1, massive MK differentiation and Fas-mediated apoptosis. Accordingly, we observed that MK-differentiating cells, derived from hematopoietic progenitors, produce VEGF, express KDR, inhibition of which reduces MK differentiation, indicating a key role of KDR in megakaryopoiesis. In conclusion, TF1-KDR cells provide a reliable model to investigate the biochemical and molecular mechanisms underlying hematopoietic progenitor proliferation, survival and MK differentiation.

Leptin activates STAT and ERK2 pathways and induces gastric cancer cell proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pai, Rama; Lin Cal; Tran, Teresa

2005-06-17

Although leptin is known to induce proliferative response in gastric cancer cells, the mechanism(s) underlying this action remains poorly understood. Here, we provide evidence that leptin-induced gastric cancer cell proliferation involves activation of STAT and ERK2 signaling pathways. Leptin-induced STAT3 phosphorylation is independent of ERK2 activation. Leptin increases SHP2 phosphorylation and enhances binding of Grb2 to SHP2. Inhibition of SHP2 expression with siRNA but not SHP2 phosphatase activity abolished leptin-induced ERK2 activation. While JAK inhibition with AG490 significantly reduced leptin-induced ERK2, STAT3 phosphorylation, and cell proliferation, SHP2 inhibition only partially reduced cancer cell proliferation. Immunostaining of gastric cancer tissues displayedmore » local overexpression of leptin and its receptor indicating that leptin might be produced and act locally in a paracrine or autocrine manner. These findings indicate that leptin promotes cancer growth by activating multiple signaling pathways and therefore blocking its action at the receptor level could be a rational therapeutic strategy.« less

Toll-like receptor-mediated inhibition of Gas6 and ProS expression facilitates inflammatory cytokine production in mouse macrophages

PubMed Central

Deng, Tingting; Zhang, Yue; Chen, Qiaoyuan; Yan, Keqin; Han, Daishu

2012-01-01

Activation of Toll-like receptors (TLRs) triggers rapid inflammatory cytokine production in various cell types. The exogenous product of growth-arrest-specific gene 6 (Gas6) and Protein S (ProS) inhibit the TLR-triggered inflammatory responses through the activation of Tyro3, Axl and Mer (TAM) receptors. However, regulation of the Gas6/ProS-TAM system remains largely unknown. In the current study, mouse macrophages are shown to constitutively express Gas6 and ProS, which synergistically suppress the basal and TLR-triggered production of inflammatory cytokines, including those of tumour necrosis factor-α, interleukin-6 and interleukin-1β, by the macrophages in an autocrine manner. Notably, TLR signalling markedly decreases Gas6 and ProS expression in macrophages through the activation of the nuclear factor-κB. Further, the down-regulation of Gas6 and ProS by TLR signalling facilitates the TLR-mediated inflammatory cytokine production in mouse macrophages. These results describe a self-regulatory mechanism of TLR signalling through the suppression of Gas6 and ProS expression. PMID:22043818

TGF-β Signaling in Dopaminergic Neurons Regulates Dendritic Growth, Excitatory-Inhibitory Synaptic Balance, and Reversal Learning.

PubMed

Luo, Sarah X; Timbang, Leah; Kim, Jae-Ick; Shang, Yulei; Sandoval, Kadellyn; Tang, Amy A; Whistler, Jennifer L; Ding, Jun B; Huang, Eric J

2016-12-20

Neural circuits involving midbrain dopaminergic (DA) neurons regulate reward and goal-directed behaviors. Although local GABAergic input is known to modulate DA circuits, the mechanism that controls excitatory/inhibitory synaptic balance in DA neurons remains unclear. Here, we show that DA neurons use autocrine transforming growth factor β (TGF-β) signaling to promote the growth of axons and dendrites. Surprisingly, removing TGF-β type II receptor in DA neurons also disrupts the balance in TGF-β1 expression in DA neurons and neighboring GABAergic neurons, which increases inhibitory input, reduces excitatory synaptic input, and alters phasic firing patterns in DA neurons. Mice lacking TGF-β signaling in DA neurons are hyperactive and exhibit inflexibility in relinquishing learned behaviors and re-establishing new stimulus-reward associations. These results support a role for TGF-β in regulating the delicate balance of excitatory/inhibitory synaptic input in local microcircuits involving DA and GABAergic neurons and its potential contributions to neuropsychiatric disorders. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Tumor Microenvironment Modulation via Gold Nanoparticles Targeting Malicious Exosomes: Implications for Cancer Diagnostics and Therapy.

PubMed

Roma-Rodrigues, Catarina; Raposo, Luís R; Cabral, Rita; Paradinha, Fabiana; Baptista, Pedro V; Fernandes, Alexandra R

2017-01-14

Exosomes are nanovesicles formed in the endosomal pathway with an important role in paracrine and autocrine cell communication. Exosomes secreted by cancer cells, malicious exosomes, have important roles in tumor microenvironment maturation and cancer progression. The knowledge of the role of exosomes in tumorigenesis prompted a new era in cancer diagnostics and therapy, taking advantage of the use of circulating exosomes as tumor biomarkers due to their stability in body fluids and targeting malignant exosomes' release and/or uptake to inhibit or delay tumor development. In recent years, nanotechnology has paved the way for the development of a plethora of new diagnostic and therapeutic platforms, fostering theranostics. The unique physical and chemical properties of gold nanoparticles (AuNPs) make them suitable vehicles to pursuit this goal. AuNPs' properties such as ease of synthesis with the desired shape and size, high surface:volume ratio, and the possibility of engineering their surface as desired, potentiate AuNPs' role in nanotheranostics, allowing the use of the same formulation for exosome detection and restraining the effect of malicious exosomes in cancer progression.

The cholinergic anti-inflammatory pathway: An innovative treatment strategy for neurological diseases.

PubMed

Han, Bin; Li, Xiuping; Hao, Junwei

2017-06-01

Acetylcholine (ACh), as a classical neurotransmitter, regulates the neuronal network in response to internal and external stimuli. In recent decades, the biology of ACh has been endowed with unparalleled new insights, especially with respect to cholinergic anti-inflammatory properties in non-neuronal cells. In fact, a mechanism frequently referred to as the "cholinergic anti-inflammatory pathway" has been termed to describe interactions between the central nervous system (CNS) and the immune system via vagus nerve. As well documented, immune cells express choline acetyltransferase, a direct synthetase for ACh, and other corresponding cholinergic components. Alternatively, the ACh released from immune cells or cholinergic neurons modulates immune function in an autocrine/paracrine manner by acting on its receptors. Moreover, muscarinic or nicotinic ACh receptors on various immune cells and CNS glial cells administer the work of their respective agonists, causing functional and biochemical changes. In this review, we focus on the anti-inflammatory benefits of non-neuronal and neuronal ACh as a means of providing new insights into treating inflammation-related neurological diseases, as exemplified by those described herein. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anaplastic lymphoma kinase: role in cancer pathogenesis and small-molecule inhibitor development for therapy

PubMed Central

Webb, Thomas R; Slavish, Jake; George, Rani E; Look, A Thomas; Xue, Liquan; Jiang, Qin; Cui, Xiaoli; Rentrop, Walter B; Morris, Stephan W

2009-01-01

Anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase in the insulin receptor superfamily, was initially identified in constitutively activated oncogenic fusion forms – the most common being nucleophosmin-ALK – in anaplastic large-cell lymphomas, and subsequent studies have identified ALK fusions in diffuse large B-cell lymphomas, systemic histiocytosis, inflammatory myofibroblastic tumors, esophageal squamous cell carcinomas and non-small-cell lung carcinomas. More recently, genomic DNA amplification and protein overexpression, as well as activating point mutations, of ALK have been described in neuroblastomas. In addition to those cancers for which a causative role for aberrant ALK activity is well validated, more circumstantial links implicate the full-length, normal ALK receptor in the genesis of other malignancies – including glioblastoma and breast cancer – via a mechanism of receptor activation involving autocrine and/or paracrine growth loops with the reported ALK ligands, pleiotrophin and midkine. This review summarizes normal ALK biology, the confirmed and putative roles of ALK in the development of human cancers and efforts to target ALK using small-molecule kinase inhibitors. PMID:19275511

The Role of Paracrine and Autocrine Signaling in the Early Phase of Adipogenic Differentiation of Adipose-derived Stem Cells

PubMed Central

Hemmingsen, Mette; Vedel, Søren; Skafte-Pedersen, Peder; Sabourin, David; Collas, Philippe; Bruus, Henrik; Dufva, Martin

2013-01-01

Introduction High cell density is known to enhance adipogenic differentiation of mesenchymal stem cells, suggesting secretion of signaling factors or cell-contact-mediated signaling. By employing microfluidic biochip technology, we have been able to separate these two processes and study the secretion pathways. Methods and results Adipogenic differentiation of human adipose-derived stem cells (ASCs) cultured in a microfluidic system was investigated under perfusion conditions with an adipogenic medium or an adipogenic medium supplemented with supernatant from differentiating ASCs (conditioned medium). Conditioned medium increased adipogenic differentiation compared to adipogenic medium with respect to accumulation of lipid-filled vacuoles and gene expression of key adipogenic markers (C/EBPα, C/EBPβ, C/EBPδ, PPARγ, LPL and adiponectin). The positive effects of conditioned medium were observed early in the differentiation process. Conclusions Using different cell densities and microfluidic perfusion cell cultures to suppress the effects of cell-released factors, we have demonstrated the significant role played by auto- or paracrine signaling in adipocyte differentiation. The cell-released factor(s) were shown to act in the recruitment phase of the differentiation process. PMID:23723991

Evidence of substance P autocrine circuitry that involves TNF-α, IL-6, and PGE2 in endogenous pyrogen-induced fever.

PubMed

Brito, Haissa Oliveira; Barbosa, Felipe L; Reis, Renata Cristiane Dos; Fraga, Daniel; Borges, Beatriz S; Franco, Celia R C; Zampronio, Aleksander Roberto

2016-04-15

Substance P (SP) is involved in fever that is induced by lipopolysaccharide (LPS) but not by interleukin-1β or macrophage inflammatory protein-1α. Intracerebroventricular (i.c.v.) administration of the neurokinin-1 (NK1) receptor antagonist SR140333B in rats reduced fever that was induced by an i.c.v. injection of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), corticotropin-releasing factor (CRF), endothelin-1 (ET-1), and morphine (MOR). Furthermore, an i.c.v. injection of SP induced a febrile response that was inhibited by indomethacin concomitant with an increase in PGE2 levels in cerebrospinal fluid. Lipopolysaccharide and PGE2 caused higher expression and internalization of NK1 receptors in the hypothalamus which were prevented by SR140333B. These data suggest that SP is an important mediator of fever, in which it induces a prostaglandin-dependent response and is released after TNF-α, IL-6, PGE2, CRF, endogenous opioids, and ET-1. Copyright © 2016 Elsevier B.V. All rights reserved.

Gut Melatonin in Vertebrates: Chronobiology and Physiology.

PubMed

Mukherjee, Sourav; Maitra, Saumen Kumar

2015-01-01

Melatonin, following discovery in the bovine pineal gland, has been detected in several extra-pineal sources including gastrointestinal tract or gut. Arylalkylamine N-acetyltransferase (AANAT) is the key regulator of its biosynthesis. Melatonin in pineal is rhythmically produced with a nocturnal peak in synchronization with environmental light-dark cycle. A recent study on carp reported first that melatonin levels and intensity of a ~23 kDa AANAT protein in each gut segment also exhibit significant daily variations but, unlike pineal, show a peak at midday in all seasons. Extensive experimental studies ruled out direct role of light-dark conditions in determining temporal pattern of gut melatoninergic system in carp, and opened up possible role of environmental non-photic cue(s) as its synchronizer. Based on mammalian findings, physiological significance of gut-derived melatonin also appears unique because its actions at local levels sharing paracrine and/or autocrine functions have been emphasized. The purpose of this mini review is to summarize the existing data on the chronobiology and physiology of gut melatonin and to emphasize their relation with the same hormone derived in the pineal in vertebrates including fish.

The roles of vascular endothelial growth factor in bone repair and regeneration

PubMed Central

Hu, Kai; Olsen, Bjorn R.

2016-01-01

Vascular endothelial growth factor-A (VEGF) is one of the most important growth factors for regulation of vascular development and angiogenesis. Since bone is a highly vascularized organ and angiogenesis plays an important role in osteogenesis, VEGF also influences skeletal development and postnatal bone repair. Compromised bone repair and regeneration in many patients can be attributed to impaired blood supply; thus, modulation of VEGF levels in bones represents a potential strategy for treating compromised bone repair and improving bone regeneration. This review (i) summarizes the roles of VEGF at different stages of bone repair, including the phases of inflammation, endochondral ossification, intramembranous ossification during callus formation and bone remodeling; (ii) discusses different mechanisms underlying the effects of VEGF on osteoblast function, including paracrine, autocrine and intracrine signaling during bone repair; (iii) summarizes the role of VEGF in the bone regenerative procedure, distraction osteogenesis; and (iv) reviews evidence for the effects of VEGF in the context of repair and regeneration techniques involving the use of scaffolds, skeletal stem cells and growth factors. PMID:27353702

Being a Neural Stem Cell: A Matter of Character But Defined by the Microenvironment.

PubMed

Andreopoulou, Evangelia; Arampatzis, Asterios; Patsoni, Melina; Kazanis, Ilias

2017-01-01

The cells that build the nervous system, either this is a small network of ganglia or a complicated primate brain, are called neural stem and progenitor cells. Even though the very primitive and the very recent neural stem cells (NSCs) share common basic characteristics that are hard-wired within their character, such as the expression of transcription factors of the SoxB family, their capacity to give rise to extremely different neural tissues depends significantly on instructions from the microenvironment. In this chapter we explore the nature of the NSC microenvironment, looking through evolution, embryonic development, maturity and even disease. Experimental work undertaken over the last 20 years has revealed exciting insight into the NSC microcosmos. NSCs are very capable in producing their own extracellular matrix and in regulating their behaviour in an autocrine and paracrine manner. Nevertheless, accumulating evidence indicates an important role for the vasculature, especially within the NSC niches of the postnatal brain; while novel results reveal direct links between the metabolic state of the organism and the function of NSCs.

Prostanoids and their receptors that modulate dendritic cell-mediated immunity.

PubMed

Gualde, Norbert; Harizi, Hedi

2004-08-01

Dendritic cells (DC) are essential for the initiation of immune responses by capturing, processing and presenting antigens to T cells. In addition to their important role as professional APC, they are able to produce immunosuppressive and pro-inflammatory prostanoids from arachidonic acid (AA) by the action of cyclooxygenase (COX) enzymes. In an autocrine and paracrine fashion, the secreted lipid mediators subsequently modulate the maturation, cytokine production, Th-cell polarizing ability, chemokine receptor expression, migration, and apoptosis of these extremely versatile APC. The biological actions of prostanoids, including their effects on APC-mediated immunity and acute inflammatory responses, are exerted by G protein-coupled receptors on plasma membrane. Some COX metabolites act as anti-inflammatory lipid mediators by binding to nuclear receptors and modulating DC functions. Although the role of cytokines in DC function has been studied extensively, the effects of prostanoids on DC biology have only recently become the focus of investigation. This review summarizes the current knowledge about the role of prostanoids and their receptors in modulating DC function and the subsequent immune responses.

The Intracrine Renin-Angiotensin System

PubMed Central

Kumar, Rajesh; Thomas, Candice M.; Yong, Qian Chen; Chen, Wen; Baker, Kenneth M.

2014-01-01

The renin-angiotensin system (RAS) is one of the earliest and most extensively studied hormonal systems. The RAS is an atypical hormonal system in several ways. The major bioactive peptide of the system, angiotensin (Ang) II, is neither synthesized in, nor targets one specific organ. New research has identified additional peptides with important physiological and pathological roles. More peptides also mean newer enzymatic cascades that generate these peptides and more receptors that mediate the function. In addition, completely different roles of components that constitute the RAS have been uncovered, such as that for prorenin via the prorenin receptor. Complexity of the RAS is further enhanced by the presence of sub-systems in tissues, which act in an autocrine/paracrine manner independent of the endocrine system. The RAS seems relevant at the cellular level, wherein individual cells have a complete system, termed the intracellular RAS. Thus, from cells to tissues to the entire organism, the RAS exhibits continuity while maintaining independent control at different levels. The intracellular RAS is a relatively new concept for the RAS. The current review presents a synopsis of the literature on this system in different tissues. PMID:22590974

Expression of platelet-derived growth factor and its receptors in proliferative disorders of fibroblastic origin.

PubMed

Smits, A; Funa, K; Vassbotn, F S; Beausang-Linder, M; af Ekenstam, F; Heldin, C H; Westermark, B; Nistér, M

1992-03-01

Platelet-derived growth factor (PDGF) is known to stimulate the proliferation of connective tissue-derived cells in vitro. Less is known about its functions in vivo, and the role of PDGF in the development of human tumors has not been clarified. The authors have investigated the occurrence of PDGF and PDGF receptors in a series of proliferative disorders of fibroblastic origin using immunohistochemical and in situ hybridization techniques. High expression of PDGF beta-receptor mRNA and protein was found in the malignant tumors, and also in some benign lesions, such as dermatofibroma. In all these cases, benign as well as malignant, the PDGF B-chain mRNA, and less clearly, the PDGF A-chain mRNA, were coexpressed with the beta-receptor. In contrast, high expression of PDGF alpha-receptor mRNA was only found in fully malignant lesions, i.e., malignant fibrous histiocytoma. These data indicate that an autocrine growth stimulation via the PDGF beta-receptor could occur in an early phase of tumorigenesis, and may be a necessary but insufficient event for the progression into fully malignant human connective tissue lesions.

The prevention of benign prostatic hyperplasia (bph).

PubMed

Roper, W G

2017-03-01

Barry Marshall and Robin Warren were the first to show that the chronic diseases (gastric ulcer and chronic gastritis) were caused by an infection (Helicobacter pylori). The chronic disease benign prostatic hyperplasia belongs to the same ilk, except that the infection process is much more subtle and complex. The enzyme Phospholipase D (PLD) which is attached to the outer membrane of Escherichia coli (E. coli) has now been almost completely proven to be the basic cause of BPH. The evidence for this process is now extremely strong and compelling. PLD obtained from the organism Streptomyces chromofuscus has been used in past research because of its PLD content. It is commercially available. In vitro, on a culture of prostatic smooth muscle, PLD stimulated the production of lysophosphatidic acid (LPA) which acted on and caused substantial growth of that muscle in accordance with the quantity of PLD/ LPA generated. It has been asserted that repeated colonization by E. coli of the transitional zone of the prostate gland and the release of PLD following repeated destruction of these colonized bacteria, is the basic cause of BPH. The evidence for colonizing and re-colonizing infection is now overwhelming. PLD is a simple lipid consisting of a phosphate, glycerol and a fatty acid. After absorption into the prostatic stroma (which consists of connective tissue and of smooth muscle), it stimulates the production of LPA which, in turn, apart from directly stimulating prostatic smooth muscle, also acts on the connective tissue in the prostate and induces a complex mixture of growth regulatory proteins, which include members of the fibroblast, insulin-like and growth transforming factor families and implicates autocrine hormones acting on the stroma and paracrine hormones acting on epithelium. Also involved, are a variety of interleukins and other inflammatory cell cytokines, secreted by the stroma, which may further promote autocrine/paracrine proliferation of BPH cells. Cadherins involved in cell adhesion and possibly chalone which exerts negative effects, must also be considered. Overall, the degree of BPH that any older male develops is governed largely by: Apart from providing the existing huge evidence for infection in BPH, this manuscript explains the production, release and absorption of PLD into the prostate gland where it is converted to LPA. This is a growth factor and acts within the prostate both on smooth muscle (research proof given) and on prostatic connective tissue, resulting in BPH. This manuscript indicates the vital research, including the requisite materials, which would readily provide irrefutable and final etiological proof of all of the hormones involved. It explains how, to a large extent, the use of a vaccine which is now being developed, would likely allow the ultimate prevention of this ubiquitous disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genomic profiling of a Hepatocyte growth factor-dependent signature for MET-targeted therapy in glioblastoma.

PubMed

Johnson, Jennifer; Ascierto, Maria Libera; Mittal, Sandeep; Newsome, David; Kang, Liang; Briggs, Michael; Tanner, Kirk; Marincola, Francesco M; Berens, Michael E; Vande Woude, George F; Xie, Qian

2015-09-17

Constitutive MET signaling promotes invasiveness in most primary and recurrent GBM. However, deployment of available MET-targeting agents is confounded by lack of effective biomarkers for selecting suitable patients for treatment. Because endogenous HGF overexpression often causes autocrine MET activation, and also indicates sensitivity to MET inhibitors, we investigated whether it drives the expression of distinct genes which could serve as a signature indicating vulnerability to MET-targeted therapy in GBM. Interrogation of genomic data from TCGA GBM (Student's t test, GBM patients with high and low HGF expression, p ≤ 0.00001) referenced against patient-derived xenograft (PDX) models (Student's t test, sensitive vs. insensitive models, p ≤ 0.005) was used to identify the HGF-dependent signature. Genomic analysis of GBM xenograft models using both human and mouse gene expression microarrays (Student's t test, treated vs. vehicle tumors, p ≤ 0.01) were performed to elucidate the tumor and microenvironment cross talk. A PDX model with EGFR(amp) was tested for MET activation as a mechanism of erlotinib resistance. We identified a group of 20 genes highly associated with HGF overexpression in GBM and were up- or down-regulated only in tumors sensitive to MET inhibitor. The MET inhibitors regulate tumor (human) and host (mouse) cells within the tumor via distinct molecular processes, but overall impede tumor growth by inhibiting cell cycle progression. EGFR (amp) tumors undergo erlotinib resistance responded to a combination of MET and EGFR inhibitors. Combining TCGA primary tumor datasets (human) and xenograft tumor model datasets (human tumor grown in mice) using therapeutic efficacy as an endpoint may serve as a useful approach to discover and develop molecular signatures as therapeutic biomarkers for targeted therapy. The HGF dependent signature may serve as a candidate predictive signature for patient enrollment in clinical trials using MET inhibitors. Human and mouse microarrays maybe used to dissect the tumor-host interactions. Targeting MET in EGFR (amp) GBM may delay the acquired resistance developed during treatment with erlotinib.

NUDT2 Disruption Elevates Diadenosine Tetraphosphate (Ap4A) and Down-Regulates Immune Response and Cancer Promotion Genes

PubMed Central

Marriott, Andrew S.; Vasieva, Olga; Fang, Yongxiang; Copeland, Nikki A.; McLennan, Alexander G.; Jones, Nigel J.

2016-01-01

Regulation of gene expression is one of several roles proposed for the stress-induced nucleotide diadenosine tetraphosphate (Ap4A). We have examined this directly by a comparative RNA-Seq analysis of KBM-7 chronic myelogenous leukemia cells and KBM-7 cells in which the NUDT2 Ap4A hydrolase gene had been disrupted (NuKO cells), causing a 175-fold increase in intracellular Ap4A. 6,288 differentially expressed genes were identified with P < 0.05. Of these, 980 were up-regulated and 705 down-regulated in NuKO cells with a fold-change ≥ 2. Ingenuity® Pathway Analysis (IPA®) was used to assign these genes to known canonical pathways and functional networks. Pathways associated with interferon responses, pattern recognition receptors and inflammation scored highly in the down-regulated set of genes while functions associated with MHC class II antigens were prominent among the up-regulated genes, which otherwise showed little organization into major functional gene sets. Tryptophan catabolism was also strongly down-regulated as were numerous genes known to be involved in tumor promotion in other systems, with roles in the epithelial-mesenchymal transition, proliferation, invasion and metastasis. Conversely, some pro-apoptotic genes were up-regulated. Major upstream factors predicted by IPA® for gene down-regulation included NFκB, STAT1/2, IRF3/4 and SP1 but no major factors controlling gene up-regulation were identified. Potential mechanisms for gene regulation mediated by Ap4A and/or NUDT2 disruption include binding of Ap4A to the HINT1 co-repressor, autocrine activation of purinoceptors by Ap4A, chromatin remodeling, effects of NUDT2 loss on transcript stability, and inhibition of ATP-dependent regulatory factors such as protein kinases by Ap4A. Existing evidence favors the last of these as the most probable mechanism. Regardless, our results suggest that the NUDT2 protein could be a novel cancer chemotherapeutic target, with its inhibition potentially exerting strong anti-tumor effects via multiple pathways involving metastasis, invasion, immunosuppression and apoptosis. PMID:27144453

NUDT2 Disruption Elevates Diadenosine Tetraphosphate (Ap4A) and Down-Regulates Immune Response and Cancer Promotion Genes.

PubMed

Marriott, Andrew S; Vasieva, Olga; Fang, Yongxiang; Copeland, Nikki A; McLennan, Alexander G; Jones, Nigel J

2016-01-01

Regulation of gene expression is one of several roles proposed for the stress-induced nucleotide diadenosine tetraphosphate (Ap4A). We have examined this directly by a comparative RNA-Seq analysis of KBM-7 chronic myelogenous leukemia cells and KBM-7 cells in which the NUDT2 Ap4A hydrolase gene had been disrupted (NuKO cells), causing a 175-fold increase in intracellular Ap4A. 6,288 differentially expressed genes were identified with P < 0.05. Of these, 980 were up-regulated and 705 down-regulated in NuKO cells with a fold-change ≥ 2. Ingenuity® Pathway Analysis (IPA®) was used to assign these genes to known canonical pathways and functional networks. Pathways associated with interferon responses, pattern recognition receptors and inflammation scored highly in the down-regulated set of genes while functions associated with MHC class II antigens were prominent among the up-regulated genes, which otherwise showed little organization into major functional gene sets. Tryptophan catabolism was also strongly down-regulated as were numerous genes known to be involved in tumor promotion in other systems, with roles in the epithelial-mesenchymal transition, proliferation, invasion and metastasis. Conversely, some pro-apoptotic genes were up-regulated. Major upstream factors predicted by IPA® for gene down-regulation included NFκB, STAT1/2, IRF3/4 and SP1 but no major factors controlling gene up-regulation were identified. Potential mechanisms for gene regulation mediated by Ap4A and/or NUDT2 disruption include binding of Ap4A to the HINT1 co-repressor, autocrine activation of purinoceptors by Ap4A, chromatin remodeling, effects of NUDT2 loss on transcript stability, and inhibition of ATP-dependent regulatory factors such as protein kinases by Ap4A. Existing evidence favors the last of these as the most probable mechanism. Regardless, our results suggest that the NUDT2 protein could be a novel cancer chemotherapeutic target, with its inhibition potentially exerting strong anti-tumor effects via multiple pathways involving metastasis, invasion, immunosuppression and apoptosis.

The PDGFRα-laminin B1-keratin 19 cascade drives tumor progression at the invasive front of human hepatocellular carcinoma

PubMed Central

Govaere, O; Petz, M; Wouters, J; Vandewynckel, Y-P; Scott, E J; Topal, B; Nevens, F; Verslype, C; Anstee, Q M; Van Vlierberghe, H; Mikulits, W; Roskams, T

2017-01-01

Human hepatocellular carcinomas (HCCs) expressing the biliary/hepatic progenitor cell marker keratin 19 (K19) have been linked with a poor prognosis and exhibit an increase in platelet-derived growth factor receptor α (PDGFRα) and laminin beta 1 (LAMB1) expression. PDGFRα has been reported to induce de novo synthesis of LAMB1 protein in a Sjogren syndrome antigen B (La/SSB)-dependent manner in a murine metastasis model. However, the role of this cascade in human HCC remains unclear. This study focused on the functional role of the PDGFRα-La/SSB-LAMB1 pathway and its molecular link to K19 expression in human HCC. In surgical HCC specimens from a cohort of 136 patients, PDGFRα expression correlated with K19 expression, microvascular invasion and metastatic spread. In addition, PDGFRα expression in pre-operative needle biopsy specimens predicted poor overall survival during a 5-year follow-up period. Consecutive histological staining demonstrated that the signaling components of the PDGFRα-La/SSB-LAMB1 pathway were strongly expressed at the invasive front. K19-positive HCC cells displayed high levels of α2β1 integrin (ITG) receptor, both in vitro and in vivo. In vitro activation of PDGFRα signaling triggered the translocation of nuclear La/SSB into the cytoplasm, enhanced the protein synthesis of LAMB1 by activating its internal ribosome entry site, which in turn led to increased secretion of laminin-111. This effect was abrogated by the PDGFRα-specific inhibitor crenolanib. Importantly LAMB1 stimulated ITG-dependent focal adhesion kinase/Src proto-oncogene non-receptor tyrosine kinase signaling. It also promoted the ITG-specific downstream target Rho-associated coiled-coil containing protein kinase 2, induced K19 expression in an autocrine manner, invadopodia formation and cell invasion. Finally, we showed that the knockdown of LAMB1 or K19 in subcutaneous xenograft mouse models resulted in significant loss of cells invading the surrounding stromal tissue and reduced HepG2 colonization into lung and liver after tail vein injection. The PDGFRα-LAMB1 pathway supports tumor progression at the invasive front of human HCC through K19 expression. PMID:28783171

Children with classic congenital adrenal hyperplasia have elevated serum leptin concentrations and insulin resistance: potential clinical implications.

PubMed

Charmandari, Evangelia; Weise, Martina; Bornstein, Stefan R; Eisenhofer, Graeme; Keil, Margaret F; Chrousos, George P; Merke, Deborah P

2002-05-01

Leptin is secreted by the white adipose tissue and modulates energy homeostasis. Nutritional, neural, neuroendocrine, paracrine, and autocrine factors, including the sympathetic nervous system and the adrenal medulla, have been implicated in the regulation of leptin secretion. Classic congenital adrenal hyperplasia (CAH) is characterized by a defect in cortisol and aldosterone secretion, impaired development and function of the adrenal medulla, and adrenal hyperandrogenism. To examine leptin secretion in patients with classic CAH in relation to their adrenomedullary function and insulin and androgen secretion, we studied 18 children with classic CAH (12 boys and 6 girls; age range 2-12 yr) and 28 normal children (16 boys and 12 girls; age range 5-12 yr) matched for body mass index (BMI). Serum leptin concentrations were significantly higher in patients with CAH than in control subjects (8.1 +/- 2.0 vs. 2.5 +/- 0.6 ng/ml, P = 0.01), and this difference persisted when leptin values were corrected for BMI. When compared with their normal counterparts, children with CAH had significantly lower plasma epinephrine (7.1 +/- 1.3 vs. 50.0 +/- 4.2, P < 0.001) and free metanephrine concentrations (18.4 +/- 2.4 vs. 46.5 +/- 4.0, P < 0.001) and higher fasting serum insulin (10.6 +/- 1.4 vs. 3.2 +/- 0.2 microU/ml, P < 0.001) and testosterone (23.7 +/- 5.3 vs. 4.6 +/- 0.5 ng/dl, P = 0.003) concentrations. Insulin resistance determined by the homeostasis model assessment method was significantly greater in children with classic CAH than in normal children (2.2 +/- 0.3 vs. 0.7 +/- 0.04, P < 0.001). Leptin concentrations were significantly and negatively correlated with epinephrine (r = -0.50, P = 0.001) and free metanephrine (r = -0.48, P = 0.002) concentrations. Stepwise multiple linear regression analysis indicated that serum leptin concentrations were best predicted by BMI in both patients and controls. Gender predicted serum leptin concentrations in controls but not in patients with classic CAH. No association was found between the dose of hydrocortisone and serum leptin (r = -0.17, P = 0.5) or insulin (r = 0.24, P = 0.3) concentrations in children with CAH. Our findings indicate that children with classic CAH have elevated fasting serum leptin and insulin concentrations, and insulin resistance. These most likely reflect differences in long-term adrenomedullary hypofunction and glucocorticoid therapy. Elevated leptin and insulin concentrations in patients with CAH may further enhance adrenal and ovarian androgen production, decrease the therapeutic efficacy of glucocorticoids, and contribute to later development of polycystic ovary syndrome and/or the metabolic syndrome and their complications.

Exosome cargo reflects TGF-β1-mediated epithelial-to-mesenchymal transition (EMT) status in A549 human lung adenocarcinoma cells.

PubMed

Kim, Jiyeon; Kim, Tae Yeon; Lee, Myung Shin; Mun, Ji Young; Ihm, Chunhwa; Kim, Soon Ae

2016-09-16

It has been suggested that tumor cells secrete exosomes to modify the local microenvironment, which then promotes intercellular communication and metastasis. Although exosomes derived from cancer cells may contribute to the epithelial-mesenchymal transition (EMT) in untransformed cells, few studies have defined exosome cargo upon induction of EMT. In this study, we investigated the changes in exosomal cargo from the epithelial to mesenchymal cell phenotype by inducing EMT with transforming growth factor (TGF)-β1 in A549 human lung adenocarcinoma cells. The protein content of the exosomes reflects the change in the cell phenotype. In addition, miR-23a was significantly enriched in the exosomes after mesenchymal transition. Following treatment of exosomes from mesenchymal cells via EMT induction with TGF-β1 to the epithelial cell type, phenotypic changes in protein expression level and cell morphology were observed. Autologous treatment of exosomes enhanced the transcriptional activity and abundance of β-catenin. Our results suggest that the exosomal protein and miRNA content reflects the physiological condition of its source and that exosomes induce phenotypic changes via autocrine signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

Feeding Frequency Affects Cultured Rat Pituitary Cells in Low Gravity

NASA Technical Reports Server (NTRS)

Hymer, W. C.; Grindeland, R. E.; Salada, T.; Cenci, R.; Krishnan, K.; Mukai, C.; Nagaoka, S.

1996-01-01

In this report, we describe the results of a rat pituitary cell culture experiment done on STS-65 in which the effect of cell feeding on the release of the six anterior pituitary hormones was studied. We found complex microgravity related interactions between the frequency of cell feeding and the quantity and quality (i.e. biological activity) of some of the six hormones released in flight. Analyses of growth hormone (GH) released from cells into culture media on different mission days using gel filtration and ion exchange chromatography yielded qualitatively similar results between ground and flight samples. Lack of cell feeding resulted in extensive cell clumping in flight (but not ground) cultures. Vigorous fibroblast growth occurred in both ground and flight cultures fed 4 times. These results are interpreted within the context of autocrine and or paracrine feedback interactions. Finally the payload specialist successfully prepared a fresh trypsin solution in microgravity, detached the cells from their surface and reinserted them back into the culture chamber. These cells reattached and continued to release hormone in microgravity. In summary, this experiment shows that pituitary cells are microgravity sensitive and that coupled operations routinely associated with laboratory cel1 culture can also be accomplished in low gravity.

A Practical Approach to Tumor Heterogeneity in Clinical Research and Diagnostics.

PubMed

Stanta, Giorgio; Bonin, Serena

2018-01-01

This Pathobiology issue tries to better define the complex phenomenon of intratumor heterogeneity (ITH), mostly from a practical point of view. This topic has been chosen because ITH is a central issue in tumor development and has to be investigated directly in patient tissue and immediately applied in the treatment of the presenting patient. Different types of ITH should be considered: clonal genetic and epigenetic evolution, morphological heterogeneity, and tumor sampling, heterogeneity resulting from microenvironmental autocrine and paracrine interaction, and stochastic plasticity related to different functional cell efficiencies. For a higher level of reproducibility in clinical research and diagnostics, it is necessary to establish standardized analytical methods, including microdissection. In situ techniques can be pivotal to explore tumor microenvironment and can be improved with associated digital analysis. Liquid biopsies for plasma DNA analysis are at present the best method to study recurrent tumors with treatment adaptation, and widespread clinical use could be beneficial. The different types of tumor genomic instabilities could have pragmatic applications to rank ITH for clinical applications: treatment approaches differ in patients with a high nucleotide mutation rate and patients with high copy number alterations. © 2017 S. Karger AG, Basel.

PCR localization of C-type natriuretic peptide and B-type receptor mRNAs in rat nephron segments.

PubMed

Terada, Y; Tomita, K; Nonoguchi, H; Yang, T; Marumo, F

1994-08-01

The present study was undertaken to investigate the presence of C-type natriuretic peptide (CNP) mRNA and its receptor, natriuretic peptide B-type receptor (ANPR-B) mRNA, in rat renal structures. The microlocalization of mRNAs coding for CNP and ANPR-B was carried out in the rat kidney, using an assay of reverse transcription and polymerase chain reaction (RT-PCR) in individual microdissected renal tubule segments, glomeruli, vasa recta bundle, and arcuate arteries. The PCR signal for CNP was detected in glomerulus, vasa recta bundle, and arcuate artery. The PCR product of ANPR-B was widely present in renal structures. Relatively large amounts of ANPR-B PCR product were detected in glomerulus, vasa recta bundle, arcuate artery, and distal nephron segments. A relatively high concentration of CNP (10(-7) M) stimulated guanosine 3',5'-cyclic monophosphate accumulation in glomerulus, medullary thick ascending limb, cortical collecting duct, and inner medullary collecting duct. Our data demonstrate that CNP can be produced locally in the glomerulus and renal vascular system and that ANPR-B is widely distributed in renal structures. Thus CNP may influence renal function and act in autocrine and paracrine fashions in the kidney.

Autocrine activity of BDNF induced by the STAT3 signaling pathway causes prolonged TrkB activation and promotes human non-small-cell lung cancer proliferation

PubMed Central

Chen, Bo; Liang, Yan; He, Zheng; An, Yunhe; Zhao, Weihong; Wu, Jianqing

2016-01-01

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin superfamily, which has been implicated in the pathophysiology of the nervous system. Recently, several studies have suggested that BDNF and/or its receptor, tropomyosin related kinase B (TrkB), are involved in tumor growth and metastasis in several cancers, including prostate cancer, neuroblastoma, pancreatic ductal carcinoma, hepatocellular carcinoma, and lung cancer. Despite the increasing emphasis on BDNF/TrkB signaling in human tumors, how it participates in primary tumors has not yet been determined. Additionally, little is known about the molecular mechanisms that elicit signaling downstream of TrkB in the progression of non-small-cell lung cancer (NSCLC). In this study, we report the significant expression of BDNF in NSCLC samples and show that BDNF stimulation increases the synthesis of BDNF itself through activation of STAT3 in lung cancer cells. The release of BDNF can in turn activate TrkB signaling. The activation of both TrkB and STAT3 contribute to downstream signaling and promote human non-small-cell lung cancer proliferation. PMID:27456333

Receptor tyrosine kinase inhibitors as potent weapons in war against cancers.

PubMed

Sharma, P Sapra; Sharma, R; Tyagi, T

2009-01-01

Receptor Tyrosine Kinases class I (RTK class I, EGF receptor family) constitute a family of transmembrane proteins involved in various aspects of cell growth and survival and have been implicated in the initiation and progression of several types of human malignancies. Activation of EGFR may be because of overexpression, mutations resulting in constitutive activation, or autocrine expression of ligand. In contrast, activation of HER2 occurs mainly by overexpression, which leads to spontaneous homodimerization and activation of downstream signaling events in a ligand-independent manner. EGFR and HER2 have now been validated as a clinically relevant target, and several different types of agents inhibiting these receptors are currently in development. The EGFR inhibitors Erlotinib, Gefitinib, and Cetuximab have undergone extensive clinical testing and have established clinical activity in non small cell lung cancer (NSCLS) and other types of solid tumors. Several of the other erbB inhibitors are also undergoing advanced clinical testing, either alone or in combination with other agents. This review reports various inhibitors, natural, small molecules and monoclonal antibodies, along with their reported activities for various members of erbB family. It will highlight the potential for the development of novel anti-cancer molecules.

Repression of the interleukin 6 gene promoter by p53 and the retinoblastoma susceptibility gene product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santhanam, U.; Ray, A.; Sehgal, P.B.

1991-09-01

The aberrant overexpression of interleukin 6 (IL-6) is implicated as an autocrine mechanism in the enhanced proliferation of the neoplastic cell elements in various B- and T-cell malignancies and in some carcinomas and sarcomas; many of these neoplasms have been shown to be associated with a mutated p53 gene. The possibility that wild-type (wt) p53, a nuclear tumor-suppressor protein, but not its transforming mutants might serve to repress IL-6 gene expression was investigated in HeLa cells. The authors transiently cotransfected these cells with constitutive cytomegalovirus (CMV) enhancer/promoter expression plasmids overproducing wt or mutant human or murine p53 and with appropriatemore » chloramphenicol acetyltransferase (CAT) reporter plasmids containing the promoter elements of human IL-6, c-fos, or {beta}-actin genes or of porcine major histocompatibility complex (MHC) class I gene in pN-38 to evaluate the effect of the various p53 species on these promoters. These observations identify transcriptional repression as a property of p53 and suggest that p53 and RB may be involved as transcriptional repressors in modulating IL-6 gene expression during cellular differentiation and oncogenesis.« less

Role of platelet-derived growth factors in physiology and medicine

PubMed Central

Andrae, Johanna; Gallini, Radiosa; Betsholtz, Christer

2008-01-01

Platelet-derived growth factors (PDGFs) and their receptors (PDGFRs) have served as prototypes for growth factor and receptor tyrosine kinase function for more than 25 years. Studies of PDGFs and PDGFRs in animal development have revealed roles for PDGFR-α signaling in gastrulation and in the development of the cranial and cardiac neural crest, gonads, lung, intestine, skin, CNS, and skeleton. Similarly, roles for PDGFR-β signaling have been established in blood vessel formation and early hematopoiesis. PDGF signaling is implicated in a range of diseases. Autocrine activation of PDGF signaling pathways is involved in certain gliomas, sarcomas, and leukemias. Paracrine PDGF signaling is commonly observed in epithelial cancers, where it triggers stromal recruitment and may be involved in epithelial–mesenchymal transition, thereby affecting tumor growth, angiogenesis, invasion, and metastasis. PDGFs drive pathological mesenchymal responses in vascular disorders such as atherosclerosis, restenosis, pulmonary hypertension, and retinal diseases, as well as in fibrotic diseases, including pulmonary fibrosis, liver cirrhosis, scleroderma, glomerulosclerosis, and cardiac fibrosis. We review basic aspects of the PDGF ligands and receptors, their developmental and pathological functions, principles of their pharmacological inhibition, and results using PDGF pathway-inhibitory or stimulatory drugs in preclinical and clinical contexts. PMID:18483217

Effects of MERTK Inhibitors UNC569 and UNC1062 on the Growth of Acute Myeloid Leukaemia Cells.

PubMed

Koda, Yuki; Itoh, Mai; Tohda, Shuji

2018-01-01

MER proto-oncogene tyrosine kinase (MERTK) is a receptor tyrosine kinase that affects cancer cell proliferation. This study evaluated the effects of the synthetic MERTK inhibitors UNC569 and UNC1062 on in vitro growth of acute myeloid leukaemia (AML) cells. Four AML cell lines expressing MERTK were treated with UNC569 and UNC1062 and analyzed for cell proliferation, immunoblotting, and gene expression. The effects of MERTK knockdown were also evaluated. Treatment with the inhibitors suppressed cell growth and induced apoptosis in all cell lines. OCI/AML5 and TMD7 cells, in which MERTK was constitutively phosphorylated by autocrine mechanisms, were highly susceptible to these inhibitors. The treatment reduced the phosphorylation of MERTK and its down-stream signalling molecules, v-akt murine thymoma viral oncogene homolog 1 (AKT) and extracellular signal-regulated kinase (ERK). Similar effects were observed after MERTK knockdown. The inhibitors and the knockdown caused similar changes in mRNA expression. These MERTK inhibitors are potential molecular-targeted drugs for treating AML expressing constitutively phosphorylated MERTK. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

The FGF21-CCL11 Axis Mediates Beiging of White Adipose Tissues by Coupling Sympathetic Nervous System to Type 2 Immunity.

PubMed

Huang, Zhe; Zhong, Ling; Lee, Jimmy Tsz Hang; Zhang, Jialiang; Wu, Donghai; Geng, Leiluo; Wang, Yu; Wong, Chi-Ming; Xu, Aimin

2017-09-05

Type 2 cytokines are important signals triggering biogenesis of thermogenic beige adipocytes in white adipose tissue (WAT) during cold acclimation. However, how cold activates type 2 immunity in WAT remains obscure. Here we show that cold-induced type 2 immune responses and beiging in subcutaneous WAT (scWAT) are abrogated in mice with adipose-selective ablation of FGF21 or its co-receptor β-Klotho, whereas such impairments are reversed by replenishment with chemokine CCL11. Mechanistically, FGF21 acts on adipocytes in an autocrine manner to promote the expression and secretion of CCL11 via activation of ERK1/2, which drives recruitment of eosinophils into scWAT, leading to increases in accumulation of M2 macrophages, and proliferation and commitment of adipocyte precursors into beige adipocytes. These FGF21-elicited type 2 immune responses and beiging are blocked by CCL11 neutralization. Thus, the adipose-derived FGF21-CCL11 axis triggers cold-induced beiging and thermogenesis by coupling sympathetic nervous system to activation of type 2 immunity in scWAT. Copyright © 2017 Elsevier Inc. All rights reserved.

The minisatellite of the GPI/AMF/NLK/MF gene: interspecies conservation and transcriptional activity.

PubMed

Williams, R R; Hassan-Walker, A F; Lavender, F L; Morgan, M; Faik, P; Ragoussis, J

2001-05-16

Minisatellites are tandemly repeated DNA sequences found throughout the genomes of all eukaryotes. They are regions often prone to instability and hence hypervariability; thus repeat unit sequence is generally not conserved beyond closely related species. We have studied the minisatellite located in intron 9 of the human glucose phosphate isomerase (GPI) gene (also known as neuroleukin, autocrine motility factor, maturation and differentiation factor) and have found, by Zoo blotting coupled with PCR amplification and DNA sequencing, that similar repeat units are present in seven other species of mammal. There is also evidence for the presence of the minisatellite in chicken. The repeat unit does not appear to be present at any other locus in these genomes. Minisatellite DNA has been reported to be involved in recombination activity, control of gene expression of nearby gene(s) (both transcriptional and translational), whilst others form protein coding regions. The high level of conservation exhibited by the GPI minisatellite, coupled with the unique location, strongly suggests a functional role. Our results from transient and stable transfections using luciferase reporter constructs have shown that the GPI minisatellite region can act to increase transcription from the SV40 promoter, CMV promoter and the human GPI promoter.

Mechanosensitive ATP Release Maintains Proper Mucus Hydration of Airways

PubMed Central

Button, Brian; Okada, Seiko F.; Frederick, Charles Brandon; Thelin, William R.; Boucher, Richard C.

2013-01-01

The clearance of mucus from the airways protects the lungs from inhaled noxious and infectious materials. Proper hydration of the mucus layer enables efficient mucus clearance through beating of cilia on airway epithelial cells, and reduced clearance of excessively concentrated mucus occurs in patients with chronic obstructive pulmonary disease and cystic fibrosis. Key steps in the mucus transport process are airway epithelia sensing and responding to changes in mucus hydration. We reported that extracellular adenosine triphosphate (ATP) and adenosine were important luminal auto-crine and paracrine signals that regulated the hydration of the surface of human airway epithelial cultures through their action on apical membrane purinoceptors. Mucus hydration in human airway epithelial cultures was sensed by an interaction between cilia and the overlying mucus layer: Changes in mechanical strain, proportional to mucus hydration, regulated ATP release rates, adjusting fluid secretion to optimize mucus layer hydration. This system provided a feedback mechanism by which airways maintained mucus hydration in an optimum range for cilia propulsion. Understanding how airway epithelia can sense and respond to changes in mucus properties helps us to understand how the mucus clearance system protects the airways in health and how it fails in lung diseases such as cystic fibrosis. PMID:23757023

Increased avidity for Dpp/BMP2 maintains the proliferation of progenitors-like cells in the Drosophila eye.

PubMed

Neto, Marta; Aguilar-Hidalgo, Daniel; Casares, Fernando

2016-10-01

During organ development, the progenitor state is transient, and depends on specific combinations of transcription factors and extracellular signals. Not surprisingly, abnormal maintenance of progenitor transcription factors may lead to tissue overgrowth, and the concurrence of signals from the local environment is often critical to trigger this overgrowth. Therefore, identifying specific combinations of transcription factors/signals promoting -or opposing- proliferation in progenitors is essential to understand normal development and disease. We have investigated this issue using the Drosophila eye as model. Transcription factors hth and tsh are transiently expressed in eye progenitors causing the expansion of the progenitor pool. However, if their co-expression is maintained experimentally, cell proliferation continues and differentiation is halted. Here we show that Hth+Tsh-induced tissue overgrowth requires the BMP2 Dpp and the abnormal hyperactivation of its pathway. Rather than using autocrine Dpp expression, Hth+Tsh cells increase their avidity for Dpp, produced locally, by upregulating extracellular matrix components. During normal development, Dpp represses hth and tsh ensuring that the progenitor state is transient. However, cells in which Hth+Tsh expression is forcibly maintained use Dpp to enhance their proliferation. Copyright © 2016 Elsevier Inc. All rights reserved.

Does IGF-1 play a role in the biology of ovarian cancer?

PubMed

Majchrzak-Baczmańska, Dominika; Malinowski, Andrzej; Głowacka, Ewa; Wilczyński, Miłosz

2018-01-01

The aim of the study was to investigate serum concentrations of the insulin-like growth factor-1 in women with ovarian cancer and healthy controls, and to compare free IGF-1 levels with selected clinical and pathological param-eters. Correlation analysis was used to measure the following: IGF-1 concentration and Ca125; IGF-1 level and the height of the OC patients. The study included 70 patients with OC and 50 healthy controls. Serum concentrations of free IGF-1 were measured in all subjects. Routine diagnostic tests (CBC and USG and Ca125) were performed. Significantly higher serum concentrations of free IGF-1 were found in the study group as compared to controls. No statistically significant relationships between IGF-1 serum concentrations and tumor differentiation, histological type, and disease stage were detected. No statistically significant correlations between IGF-1 and Ca125 level or between IGF-1 and growth of OC patients were found. Serum IGF-1 participates in the etiopathogenesis of ovarian cancer in menstruating women, while local synthesis of this factor and other components of the autocrine loop of the IGF-1 system play a greater role in their post-menopausal peers.

Human conditions of insulin-like growth factor-I (IGF-I) deficiency

PubMed Central

2012-01-01

Insulin-like growth factor I (IGF-I) is a polypeptide hormone produced mainly by the liver in response to the endocrine GH stimulus, but it is also secreted by multiple tissues for autocrine/paracrine purposes. IGF-I is partly responsible for systemic GH activities although it possesses a wide number of own properties (anabolic, antioxidant, anti-inflammatory and cytoprotective actions). IGF-I is a closely regulated hormone. Consequently, its logical therapeutical applications seems to be limited to restore physiological circulating levels in order to recover the clinical consequences of IGF-I deficiency, conditions where, despite continuous discrepancies, IGF-I treatment has never been related to oncogenesis. Currently the best characterized conditions of IGF-I deficiency are Laron Syndrome, in children; liver cirrhosis, in adults; aging including age-related-cardiovascular and neurological diseases; and more recently, intrauterine growth restriction. The aim of this review is to summarize the increasing list of roles of IGF-I, both in physiological and pathological conditions, underlying that its potential therapeutical options seem to be limited to those proven states of local or systemic IGF-I deficiency as a replacement treatment, rather than increasing its level upper the normal range. PMID:23148873

Prostaglandin E(2) and insulin-like growth factor I interact to enhance proliferation of theca externa cells from chicken prehierarchical follicles.

PubMed

Jia, Yudong; Lin, Jinxing; Mi, Yuling; Zhang, Caiqiao

2013-10-01

The interactive effect of insulin-like growth factor I (IGF-I) and prostaglandin E2 (PGE2) on the proliferation of theca externa cells (TECs) was investigated in the prehierarchical small yellow follicles of laying hens. IGF-I manifested a proliferating effect like PGE2 on TECs, but this stimulating effect was restrained by AG1024 (IGF-IR inhibitor), KP372-1 (PKB/AKT inhibitor) or NS398 (COX-2 inhibitor). AG1024, KP372-1 or NS398 abolished IGF-I-stimulated COX-2 expression and PGE2 production. Meanwhile, KP372-1, NS398 or AG1024 depressed the PGE2-stimulated expression of COX-2 and IGF-IR mRNA. Therefore, the IGF-I receptor pathway up-regulates COX-2 expression and PGE2 synthesis via PKB signaling cascade, and then PGE2 stimulates IGF-IR mRNA expression to promote TEC proliferation in an autocrine pattern. Overall, the reciprocal stimulation of intracellular PGE2 and IGF-I may enhance TEC proliferation and facilitate the development of chicken prehierarchical follicles. Copyright © 2013 Elsevier Inc. All rights reserved.

Apoptosis resistance in epithelial tumors is mediated by tumor-cell-derived interleukin-4.

PubMed

Todaro, M; Lombardo, Y; Francipane, M G; Alea, M Perez; Cammareri, P; Iovino, F; Di Stefano, A B; Di Bernardo, C; Agrusa, A; Condorelli, G; Walczak, H; Stassi, G

2008-04-01

We investigated the mechanisms involved in the resistance to cell death observed in epithelial cancers. Here, we identify that primary epithelial cancer cells from colon, breast and lung carcinomas express high levels of the antiapoptotic proteins PED, cFLIP, Bcl-xL and Bcl-2. These cancer cells produced interleukin-4 (IL-4), which amplified the expression levels of these antiapoptotic proteins and prevented cell death induced upon exposure to TRAIL or other drug agents. IL-4 blockade resulted in a significant decrease in the growth rate of epithelial cancer cells and sensitized them, both in vitro and in vivo, to apoptosis induction by TRAIL and chemotherapy via downregulation of the antiapoptotic factors PED, cFLIP, Bcl-xL and Bcl-2. Furthermore, we provide evidence that exogenous IL-4 was able to upregulate the expression levels of these antiapoptotic proteins and potently stabilized the growth of normal epithelial cells rendering them apoptosis resistant. In conclusion, IL-4 acts as an autocrine survival factor in epithelial cells. Our results indicate that inhibition of IL-4/IL-4R signaling may serve as a novel treatment for epithelial cancers.

Dendritic cell reprogramming by endogenously produced lactic acid.

PubMed

Nasi, Aikaterini; Fekete, Tünde; Krishnamurthy, Akilan; Snowden, Stuart; Rajnavölgyi, Eva; Catrina, Anca I; Wheelock, Craig E; Vivar, Nancy; Rethi, Bence

2013-09-15

The demand for controlling T cell responses via dendritic cell (DC) vaccines initiated a quest for reliable and feasible DC modulatory strategies that would facilitate cytotoxicity against tumors or tolerance in autoimmunity. We studied endogenous mechanisms in developing monocyte-derived DCs (MoDCs) that can induce inflammatory or suppressor programs during differentiation, and we identified a powerful autocrine pathway that, in a cell concentration-dependent manner, strongly interferes with inflammatory DC differentiation. MoDCs developing at low cell culture density have superior ability to produce inflammatory cytokines, to induce Th1 polarization, and to migrate toward the lymphoid tissue chemokine CCL19. On the contrary, MoDCs originated from dense cultures produce IL-10 but no inflammatory cytokines upon activation. DCs from high-density cultures maintained more differentiation plasticity and can develop to osteoclasts. The cell concentration-dependent pathway was independent of peroxisome proliferator-activated receptor γ (PPARγ), a known endogenous regulator of MoDC differentiation. Instead, it acted through lactic acid, which accumulated in dense cultures and induced an early and long-lasting reprogramming of MoDC differentiation. Our results suggest that the lactic acid-mediated inhibitory pathway could be efficiently manipulated in developing MoDCs to influence the immunogenicity of DC vaccines.

Quantifying the vitamin D economy.

PubMed

Heaney, Robert P; Armas, Laura A G

2015-01-01

Vitamin D enters the body through multiple routes and in a variety of chemical forms. Utilization varies with input, demand, and genetics. Vitamin D and its metabolites are carried in the blood on a Gc protein that has three principal alleles with differing binding affinities and ethnic prevalences. Three major metabolites are produced, which act via two routes, endocrine and autocrine/paracrine, and in two compartments, extracellular and intracellular. Metabolic consumption is influenced by physiological controls, noxious stimuli, and tissue demand. When administered as a supplement, varying dosing schedules produce major differences in serum metabolite profiles. To understand vitamin D's role in human physiology, it is necessary both to identify the foregoing entities, mechanisms, and pathways and, specifically, to quantify them. This review was performed to delineate the principal entities and transitions involved in the vitamin D economy, summarize the status of present knowledge of the applicable rates and masses, draw inferences about functions that are implicit in these quantifications, and point out implications for the determination of adequacy. © The Author(s) 2014. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Control of brain development and homeostasis by local and systemic insulin signalling.

PubMed

Liu, J; Spéder, P; Brand, A H

2014-09-01

Insulin and insulin-like growth factors (IGFs) are important regulators of growth and metabolism. In both vertebrates and invertebrates, insulin/IGFs are made available to various organs, including the brain, through two routes: the circulating systemic insulin/IGFs act on distant organs via endocrine signalling, whereas insulin/IGF ligands released by local tissues act in a paracrine or autocrine fashion. Although the mechanisms governing the secretion and action of systemic insulin/IGF have been the focus of extensive investigation, the significance of locally derived insulin/IGF has only more recently come to the fore. Local insulin/IGF signalling is particularly important for the development and homeostasis of the central nervous system, which is insulated from the systemic environment by the blood-brain barrier. Local insulin/IGF signalling from glial cells, the blood-brain barrier and the cerebrospinal fluid has emerged as a potent regulator of neurogenesis. This review will address the main sources of local insulin/IGF and how they affect neurogenesis during development. In addition, we describe how local insulin/IGF signalling couples neural stem cell proliferation with systemic energy state in Drosophila and in mammals. © 2014 John Wiley & Sons Ltd.

Matrix remodeling maintains ESC self-renewal by activating Stat3

PubMed Central

Przybyla, Laralynne M.; Theunissen, Thorold W.; Jaenisch, Rudolf; Voldman, Joel

2013-01-01

While a variety of natural and synthetic matrices have been used to influence embryonic stem cell (ESC) self-renewal or differentiation, and ESCs also deposit a rich matrix of their own, the mechanisms behind how extracellular matrix affects cell fate are largely unexplored. The ESC matrix is continuously remodeled by matrix metalloproteinases (MMPs), a process that we find is enhanced by the presence of mouse embryonic fibroblast feeders in a paracrine manner. Matrix remodeling by MMPs aids in the self-renewal of ESCs, as inhibition of MMPs inhibits the ability of ESCs to self-renew. We also find that addition of the interstitial collagenase MMP1 is sufficient to maintain long-term LIF-independent mESC self-renewal in a dose-dependent manner. This remarkable ability is due to the presence of endogenously produced self-renewal-inducing signals, including the LIF-family ligand CNTF, that are normally trapped within the ECM and become exposed upon MMP-induced matrix remodeling to signal through JAK and Stat3. These results uncover a new role for feeder cells in maintaining self-renewal and show that mESCs normally produce sufficient levels of autocrine-acting pro-self-renewal ligands. PMID:23404867

Physiology of Mechanotransduction: How Do Muscle and Bone "Talk" to One Another?

PubMed

Isaacson, Janalee; Brotto, Marco

2014-06-01

The complexity of cell interactions with their microenvironment and their ability to communicate at the autocrine, paracrine, and endocrine levels has gradually but significantly evolved in the last three decades. The musculoskeletal system has been historically recognized to be governed by a relationship of proximity and function, chiefly dictated by mechanical forces and the work of gravity itself. In this review article, we first provide a historical overview of the biomechanical theory of bone- muscle interactions. Next, we expand to detail the significant evolution in our understanding of the function of bones and muscles as secretory organs. Then, we review and discuss new evidence in support of a biochemical interaction between these two tissues. We then propose that these two models of interaction are complementary and intertwined providing for a new frontier for the investigation of how bone-muscle cross talk could be fully explored for the targeting of new therapies for musculoskeletal diseases, particularly the twin conditions of aging, osteoporosis and sarcopenia. In the last section, we explore the bone-muscle cross talk in the context of their interactions with other tissues and the global impact of these multi-tissue interactions on chronic diseases.

Physiology of Mechanotransduction: How Do Muscle and Bone “Talk” to One Another?

PubMed Central

Isaacson, Janalee

2015-01-01

The complexity of cell interactions with their microenvironment and their ability to communicate at the autocrine, paracrine, and endocrine levels has gradually but significantly evolved in the last three decades. The musculoskeletal system has been historically recognized to be governed by a relationship of proximity and function, chiefly dictated by mechanical forces and the work of gravity itself. In this review article, we first provide a historical overview of the biomechanical theory of bone– muscle interactions. Next, we expand to detail the significant evolution in our understanding of the function of bones and muscles as secretory organs. Then, we review and discuss new evidence in support of a biochemical interaction between these two tissues. We then propose that these two models of interaction are complementary and intertwined providing for a new frontier for the investigation of how bone–muscle cross talk could be fully explored for the targeting of new therapies for musculoskeletal diseases, particularly the twin conditions of aging, osteoporosis and sarcopenia. In the last section, we explore the bone–muscle cross talk in the context of their interactions with other tissues and the global impact of these multi-tissue interactions on chronic diseases. PMID:25838800

A Novel Role of Peripheral Corticotropin-Releasing Hormone (CRH) on Dermal Fibroblasts

PubMed Central

Rassouli, Olga; Liapakis, George; Lazaridis, Iakovos; Sakellaris, George; Gkountelias, Kostas; Gravanis, Achille; Margioris, Andrew N.

2011-01-01

Corticotropin-releasing hormone, or factor, (CRH or CRF) exerts important biological effects in multiple peripheral tissues via paracrine/autocrine actions. The aim of our study was to assess the effects of endogenous CRH in the biology of mouse and human skin fibroblasts, the primary cell type involved in wound healing. We show expression of CRH and its receptors in primary fibroblasts, and we demonstrate the functionality of fibroblast CRH receptors by induction of cAMP. Fibroblasts genetically deficient in Crh (Crh−/−) had higher proliferation and migration rates and compromised production of IL-6 and TGF-β1 compared to the wildtype (Crh+/+) cells. Human primary cultures of foreskin fibroblasts exposed to the CRF1 antagonist antalarmin recapitulated the findings in the Crh−/− cells, exhibiting altered proliferative and migratory behavior and suppressed production of IL-6. In conclusion, our findings show an important role of fibroblast-expressed CRH in the proliferation, migration, and cytokine production of these cells, processes associated with the skin response to injury. Our data suggest that the immunomodulatory effects of CRH may include an important, albeit not explored yet, role in epidermal tissue remodeling and regeneration and maintenance of tissue homeostasis. PMID:21765902