Mitogenic Research Articles

The role of bile salts in liver regeneration.

A growing body of evidence has demonstrated that bile salts are important for liver regeneration following partial hepatectomy. The relative bile salt overload after partial liver resection causes activation of bile salt receptors in non-parenchymal (viz. the plasma membrane receptor TGR5) and parenchymal (viz. the intracellular receptor FXR) cells in the liver, thus, providing signals to the regenerative process. Impaired bile salt signaling in mice with genetic deficiency of Tgr5 or Fxr results in delayed liver regeneration after partial hepatectomy, and is accompanied by mortality in case of Fxr knock-out mice. Conversely, compensatory liver re-growth in hepatectomized mice can be stimulated by feeding of bile salts or alisol B 23-acetate, a natural triterpenoid agonist of Fxr. A large number of animal studies underscore the importance of strict maintenance of bile salt homeostasis for proper progression of liver regeneration. Both ileal and hepatic Fxr play a key role in regulation of bile salt homeostasis and, thus, preventing hepatotoxicity caused by excessive levels of bile salts. They further contribute to liver regeneration by induction of mitogenic factors. Agents that target bile salt receptors hold promise as drugs to stimulate liver regeneration in selected patients.

Reactive Oxygen Species‐Dependent PKB Activation Contributes to Insulin‐Like Growth Factor 1‐Induced Phosphorylation of Histone Deacetylase 5 in Vascular Smooth Muscle Cells

Insulin‐like growth factor 1 (IGF‐1), a potent mitogenic and vasoactive factor, has been shown to play an important role in the development of cardiovascular diseases. This occurs through the generation of reactive oxygen species (ROS) as well as through the hyperactivation of mitogenic and growth promoting signaling pathways and the subsequent alteration in gene expression. Histone deacetylases (HDACs), by their ability to modify the acetylation status of lysine residues in histone and non‐histone proteins, regulate gene transcription. Recent studies have demonstrated that a heightened activation of HDACs, notably HDAC5, is associated with vascular disorders such as atherosclerosis. However, a role of IGF‐1 in HDAC activation by phosphorylation remains poorly characterized. Therefore, in the present studies, we examined the effect of IGF‐1 on the phosphorylation of HDAC5 in vascular smooth muscle cells (VSMCs) and identified the signalling pathways involved in this process. Treatment of A10 VSMCs with IGF‐1 enhanced the phosphorylation of HDAC5 at serine 498 in a time and dose‐dependent fashion. Pretreatment of cells with AG1024, a selective pharmacological inhibitor of IGF‐1 receptor, significantly inhibited IGF‐1‐induced HDAC5 phosphorylation in A10 VSMCs whereas AG1478, a selective inhibitor of epidermal growth factor receptor, did not have an inhibitory effect on the levels of phospho‐HDAC5. Pharmacological blockade of the MAPK pathway with PD98059 and UO126 had no effect on HDAC5 phosphorylation, however wortmannin and SC‐66, inhibitors of the PI3K/PKB pathways, almost completely attenuated IGF‐1‐induced HDAC5 phosphorylation. In addition, pretreatment of A10 VSMCs with Diphenyleneiodonium (DPI) and apocynin, two NAD(P)H oxidase inhibitors, as well as the antioxidant N‐Acetyl‐Cysteine (NAC), resulted in an attenuation of IGF‐1‐induced phosphorylation of HDAC5 as well as PKB. In summary, these data demonstrate that IGF‐1 induces the phosphorylation of HDAC5 in a ROS‐ and PKB‐dependent fashion in VSMCs.Support or Funding InformationSupported by a grant from the Canadian Institutes of Health Research.

HB-EGF-Promoted Airway Smooth Muscle Cells and Their Progenitor Migration Contribute to Airway Smooth Muscle Remodeling in Asthmatic Mouse.

The airway smooth muscle (ASM) cells' proliferation, migration, and their progenitor's migration are currently regarded as causative factors for ASM remodeling in asthma. Heparin-binding epidermal growth factor (HB-EGF), a potent mitogen and chemotactic factor, could promote ASM cell proliferation through MAPK pathways. In this study, we obtained primary ASM cells and their progenitors from C57BL/6 mice and went on to explore the role of HB-EGF in these cells migration and the underlying mechanisms. We found that recombinant HB-EGF (rHB-EGF) intratracheal instillation accelerated ASM layer thickening in an OVA-induced asthmatic mouse. Modified Boyden chamber assay revealed that rHB-EGF facilitate ASM cell migration in a dose-dependent manner and ASM cells from asthmatic mice had a greater migration ability than that from normal counterparts. rHB-EGF could stimulate the phosphorylation of ERK1/2 and p38 in ASM cells but further migration assay showed that only epidermal growth factor receptor inhibitor (AG1478) or p38 inhibitor (SB203580), but not ERK1/2 inhibitor (PD98059), could inhibit rHB-EGF-mediated ASM cells migration. Actin cytoskeleton experiments exhibited that rHB-EGF could cause actin stress fibers disassembly and focal adhesions formation of ASM cells through the activation of p38. Finally, airway instillation of rHB-EGF promoted the recruitment of bone marrow-derived smooth muscle progenitor cells, which were transferred via caudal vein, migrating into the airway from the circulation. These observations demonstrated that ASM remodeling in asthma might have resulted from HB-EGF-mediated ASM cells and their progenitor cells migration, via p38 MAPK-dependent actin cytoskeleton remodeling.

Extracellular Reactive Oxygen Species Drive Apoptosis-Induced Proliferation via Drosophila Macrophages

Apoptosis-induced proliferation (AiP) is a compensatory mechanism to maintain tissue size and morphology following unexpected cell loss during normal development, and may also be a contributing factor to cancer and drug resistance. In apoptotic cells, caspase-initiated signaling cascades lead to the downstream production of mitogenic factors and the proliferation of neighboring surviving cells. In epithelial cells of Drosophila imaginal discs, the Caspase-9 ortholog Dronc drives AiP via activation of Jun N-terminal kinase (JNK); however, the specific mechanisms of JNK activation remain unknown. Here we show that caspase-induced activation of JNK during AiP depends on an inflammatory response. This is mediated by extracellular reactive oxygen species (ROSs) generated by the NADPH oxidase Duox in epithelial disc cells. Extracellular ROSs activate Drosophila macrophages (hemocytes), which in turn trigger JNK activity in epithelial cells by signaling through the tumor necrosis factor (TNF) ortholog Eiger. We propose that in an immortalized ("undead") model of AiP, signaling back and forth between epithelial disc cells and hemocytes by extracellular ROSs and TNF/Eiger drives overgrowth of the disc epithelium. These data illustrate a bidirectional cell-cell communication pathway with implication for tissue repair, regeneration, and cancer.

Cardiac Extracellular Vesicles in Normal and Infarcted Heart

Heart is a complex assembly of many cell types constituting myocardium, endocardium and epicardium that intensively communicate to each other in order to maintain the proper cardiac function. There are many types of intercellular intracardiac signals, with a prominent role of extracellular vesicles (EVs), such as exosomes and microvesicles, for long-distant delivering of complex messages. Cardiomyocytes release EVs, whose content could significantly vary depending on the stimulus. In stress, such as hypoxia, inflammation or injury, cardiomyocytes increase secretion of EVs. In hypoxic conditions, cardiac EVs are enriched with angiogenic and prosurvival factors. In acute myocardial infarction (AMI), damaged cardiac muscle cells produce EVs with increased content of angiogenic, anti-apoptotic, mitogenic and growth factors in order to induce repair and healing of the infarcted myocardium. Exosomal microRNAs play a central role in cardiac regeneration. In AMI, circulating cardiac EVs abundantly contain cardiac-specific miRNAs that serve as indicators of cardiac damage and have a big diagnostic potential as AMI biomarkers. Cardioprotective and regenerative properties of exosomes derived from cardiac and non-cardiac stem/progenitor cells are very helpful to be used in cell-free cardiotherapy and regeneration of post-infarct myocardium.

Raf Kinase Inhibitor Protein (RKIP) expression and function in human myometrium and leiomyoma

Many growth factors been identified in human myometrium and leiomyoma and activate multiple signaling pathways in order to regulate major cellular processes, including proliferation and fibrosis which are linked to uterine leiomyoma development and growth. The Raf kinase inhibitor protein (RKIP) has emerging roles as regulator of multiple signaling networks including mitogen activated protein (MAP) kinase cascade, as well as interaction with glycogen synthase kinase 3 (GSK3). In our study, we aimed to investigate the presence of RKIP in human myometrium and leiomyoma as well as to determine the effect of locostatin (RKIP inhibitor) on extracellular matrix (ECM) production, proliferation and migration in human myometrial and leiomyoma cells. Myometrial and leiomyoma tissues were used to investigate the localization and the expression level of RKIP through immunohistochemistry and western blotting. Myometrial and leiomyoma cells were treated with locostatin to measure ECM expression by real time PCR, GSK3b expression by western blotting, cell migration by wound-healing assay and cell proliferation by MTT assay. We found that RKIP is expressed in human myometrial and leiomyoma tissue. Locostatin treatment resulted in the activation of the MAPK signal pathway (ERK phosphorylation), providing a powerful validation of our targeting protocol. Further, RKIP inhibition by locostatin reduces ECM components. Moreover, the inhibition of RKIP by locostatin impaired cell proliferation and migration in both leiomyoma and myometrial cells. Finally, locostatin treatment reduced GSK3β expression. Therefore, even if the activation of MAPK pathway should increase proliferation and migration, the destabilization of GSK3β leads to the reduction of proliferation and migration of myometrial and leiomyoma cells.

Ameliorative effect of VIP family members on blood retinal barrier breakdown in diabetic macular edema

Diabetic macular edema (DME) is one of the main complications of diabetic retinopathy [1]. This pathology is owed to impairment of the blood-retinal barrier (BRB) [2]. Many factors, such as hypoxia, contribute to barrier dysfunction and progression of the disease. Low oxygen tension is one of the main events involved in the formation of new blood vessels that characterize the typical uncontrolled angiogenesis in proliferative stage of diabetic retinopathy. In the last decades, various studies have focused their attention on the role of pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) in the pathophysiology of DME. However, the effects of these peptides in maintaining the integrity of the BRB exposed to hypoxia remains to be elucidated. In the present work we have studied, for the first time, the effect of these peptides on outer BRB integrity following hypoxic insult in an experimental model of DME. To this end, we have used the human retinal pigment epithelial cells (ARPE-19) to test the effect of both peptides on cellular permeability, transepithelial electrical resistance, tight junctions expression and hypoxia-induced apoptosis. Results have demonstrated that both PACAP and VIP are able to rescue the integrity of cell monolayer during the hypoxic event, minimizing apoptotic damages induced by low tissue oxygen tension through the activation of phosphoinositide 3 kinase /Akt and mammalian mitogen activated protein kinase/Erk kinase signaling pathways. Furthermore, these peptides modulate the expression of vascular endothelial growth factor which is one of the downstream transcription factor activated during the hypoxic process. In conclusion, we have demonstrated that PACAP and VIP are able to counteract the damage induced by hypoxia on BRB through the modulation of hypoxia inducible factors expression.

SAPHIRE: Stress and Pulmonary Hypertension in Rheumatoid Evaluation-A Prevalence Study.

Pulmonary artery hypertension (PAH) is a disorder of elevated resistance in the pulmonary arterial vessels, reflected by elevation of measured pulmonary artery pressure (PAP), and presenting with breathlessness and, if untreated, progressing to right heart failure and death. The heightened prevalence of PAH in populations with underlying systemic autoimmune conditions, particularly scleroderma and its variants, is well recognised, consistent with the proposed autoimmune contribution to PAH pathogenesis, along with disordered thrombotic, inflammatory, and mitogenic factors. Rheumatoid arthritis (RA) is one of a group of systemic autoimmune conditions featuring inflammatory symmetrical erosive polyarthropathy as its hallmark. This study explored the prevalence of PAH in a population of unselected individuals with RA, using exercise echocardiography (EchoCG). The high prevalence of EchoCG-derived elevation of PAP (EDEPP) in this population (14%) suggests that, like other autoimmune conditions, RA may be a risk factor for PAH. Patients with RA may therefore represent another population for whom PAH screening with noninvasive tools such as EchoCG may be justified.

Effect of Epidermal Growth Factor on the Network Spiking Activity in Cultured Hippocampal Neurons

Effect of Epidermal Growth Factor on the Network Spiking Activity in Cultured Hippocampal Neurons

Oncogenic role of leptin and Notch interleukin-1 leptin crosstalk outcome in cancer.

Obesity is a global pandemic characterized by high levels of body fat (adiposity) and derived-cytokines (i.e., leptin). Research shows that adiposity and leptin provide insight on the link between obesity and cancer progression. Leptin's main function is to regulate energy balance. However, obese individuals routinely develop leptin resistance, which is the consequence of the breakdown in the signaling mechanism controlling satiety resulting in the accumulation of leptin. Therefore, leptin levels are often chronically elevated in human obesity. Elevated leptin levels are related to higher incidence, increased progression and poor prognosis of several human cancers. In addition to adipose tissue, cancer cells can also secrete leptin and overexpress leptin receptors. Leptin is known to act as a mitogen, inflammatory and pro-angiogenic factor that induces cancer cell proliferation and tumor angiogenesis. Moreover, leptin signaling induces cancer stem cells, which are involved in cancer recurrence and drug resistance. A novel and complex signaling crosstalk between leptin, Notch and interleukin-1 (IL-1) [Notch, IL-1 and leptin crosstalk outcome (NILCO)] seems to be an important driver of leptin-induced oncogenic actions. Leptin and NILCO signaling mediate the activation of cancer stem cells that can affect drug resistance. Thus, leptin and NILCO signaling are key links between obesity and cancer progression. This review presents updated data suggesting that adiposity affects cancer incidence, progression, and response to treatment. Here we show data supporting the oncogenic role of leptin in breast, endometrial, and pancreatic cancers.

Platelet derived growth factor B gene expression in the Xenopus laevis developing central nervous system.

Platelet-derived growth factor B (PDGF-B) belongs to the mitogen and growth factor family and like the other members it has many roles in cell differentiation, proliferation and migration during development, adult life and in pathological conditions. Among them it has been observed that aberrant PDGF signalling is frequently linked to glioma development and progression, and Pdgf-b over-expression in mouse neural progenitors leads to the formation of gliomas. Despite this evidence, the mechanisms underlying PDGF-B driven tumorigenesis and its role during brain development are not fully understood. In order to contribute to clarifying possible new roles of pdgf-b signalling, we present here the embryonic gene expression pattern of pdgf-b, so far unknown in early vertebrate development. By using Xenopus laevis as a model system we performed qRT-PCR and whole mount in situ hybridization. Pdgf-b mRNA is expressed in discrete regions of the developing central nervous system, in the cranial nerve placodes and in the notochord. We also compared the gene expression of pdgf-b with that of its receptor pdgfr-α suggesting so far unsuspected roles for this signalling pathway during the development of specific embryonic structures.

Loss of the Tumor Suppressor NKX3.1 in Prostate Cancer Cells is Induced by Prostatitis Related Mitogens

Objective: Prostate carcinoma (PCa) is the leading causes of cancer-related death in elderly men. Although several risk factors for the development of prostate cancer have been identified, the impact of chronic prostatitis is still a matter of debate. A key event of prostate cancer pathogenesis is the decrease of the homeo box protein NKX3.1 in the luminal epithelial cells of the prostate observed in early pre-cancerous lesions. Furthermore, inactivation of Nkx3.1 in a mouse model led to high incidence of prostatic intraepithelial neoplasia (PIN) formation underscoring the importance of NKX3.1 loss. In this study, we aimed to define the impact of diverse cytokines and growth factors known to be expressed during chronic prostatitis on NKX3.1 expression. Methods: We determined the NKX3.1 expression in inflamed areas of prostatectomy specimens by immunohistochemistry. NKX3.1 protein and mRNA levels in cytokine and growth factor stimulated PCa cell lines were determined by western blot and RTqPCR. Transcriptional activity of the androgen receptor (AR) was determined by luciferase reporter assays and impact of the AR on NKX3.1 expression by siRNA mediated AR knock down. Results: Treatment of prostate carcinoma cell lines with epidermal growth factor (EGF) dramatically reduced NKX3.1 protein and mRNA levels, while TNFα or IL-1α had only a moderate effect. Moreover, EGF or a combination of PMA and ionomycin (P+I) also caused diminished levels of the AR. However, while NKX3.1 reduction is observed as early as one hour after stimulation the decrease of AR occurred with a delayed kinetic. We show that P+I-induced NKX3.1 proteolysis is proteasome-dependent and influenced by protein kinase C. Conclusion: In summary, we provide evidences for a crucial role of inflammatory mitogenic factors leading to reduced NKX3.1 and AR levels which might contribute to the initiation of pre-cancerous PIN lesions.

Leptin serves as angiogenic/mitogenic factor in melanoma tumor growth.

Background:Tumor development is angiogenesis dependent. There is evidence that leptin contributes to tumor growth. However, all the mechanisms by which leptin does this has not been clearly established. The objective of the present study was to test the hypothesis that leptin enhances melanoma tumor growth through inducing angiogenesis and cell proliferation.Materials and Methods:We injected 2 × 106 B16F10 melanoma cells subcutaneously to 32 C57BL6 mice. The mice were randomly divided into four groups of eight animals, on day 8. Two groups received twice daily intraperitoneal (i.p.) injections of either phosphate buffered saline or recombinant murine leptin (1 μg/g initial body weight). Two groups received i.p. injections of either 9F8 an anti leptin receptor antibody or the control mouse IgG at 50 μg/injection every 3 consecutive days. By the end of the 2nd week, the animals were euthanized and blood samples and tumors were analyzed. Angiogenesis and proliferation were assessed by immunohistochemical staining for CD31 and Ki-67 respectively.Results:Tumors size, capillary density, plasma levels of vascular endothelial growth factor, and the number of Ki-67-positive stained cells were significantly more in the leptin than 9F8 and both control groups (P < 0.05).Conclusion:Taken together, our findings reinforce the idea that leptin acts as an angiogenic and mitogenic factor to promote melanoma growth.

Combined delivery of PDGF-BB and BMP-6 for enhanced osteoblastic differentiation

Natural microenvironment during bone tissue regeneration involves integration of multiple biological growth factors which regulate mitogenic activities and differentiation to induce bone repair. Among them platelet derived growth factor (PDGF-BB) and bone morphogenic protein-6 (BMP-6) are known to play a prominent role. The aim of this study was to investigate the benefits of combined delivery of PDGF-BB and BMP-6 on proliferation and osteoblastic differentiation of MC3T3-E1 preosteoblastic cells. PDGF-BB and BMP-6 were loaded in gelatin and poly (3-hydroxybutyric acid-co-3-hydroxyvaleric acid) particles, respectively. The carrier particles were then loaded into 3D chitosan matrix fabricated by freeze drying. The fast release of PDGF-BB during 7 days was accompanied by slower and prolonged release of BMP-6. The premising release of mitogenic factor PDGF-BB resulted in an increased MC3T3-E1 cell population seeded on chitosan scaffolds. Osteogenic markers of RunX2, Col 1, OPN were higher on chitosan scaffolds loaded with growth factors either individually or in combination. However, OCN expression and bone mineral formation were prominent on chitosan scaffolds incorporating PDGF-BB and BMP-6 as a combination.

Roles of cell signaling pathways in thyroid carcinoma

The intracellular signal transduction pathways play an important role in the occurrence and development of thyroid cancer. Mitogen activated protein kinase (MAPK) signal transduction pathway, phosphatidylinositol 3-kinase (PI3K)-AKT pathway, NF-κB pathway and RASSF1-MST1-FOXO3 pathway affect the occurrence and development of thyroid cancer by modulating the activity and expression of specifical proteins, and determine the growth and apoptosis of thyroid cancer cells. Key words: Thyroid neoplasms; Signal transduction pathways

CCN2 - Exploring a New Biomarker in Myelofibrosis

BACKGROUNDBone marrow fibrosis in myelofibrosis (MF) is the result of a complex and poorly understood interaction between megakaryocytes, fibroblasts, endothelial cells, cytokines and marrow stroma. Preclinical studies support a pathobiological role of TGF-β. It is overexpressed by megakaryocytes in MF and the TGF-β signature is upregulated and has been targeted in MF animal models. However TGF-β is a pleiotropic cytokine implicated in many cellular processes. CCN proteins are a group of 6 matricellular proteins important in fibrotic diseases and injury repair. CCN1 (CYR61) and CCN2 (CTGF) are transcriptionally activated by mitogenic growth factors such as PDGF, FGF2 and TGF-β. Recombinant CCN2 induces differentiation of human bone marrow mesenchymal stem cells into fibroblasts (Lee et al. JCI 2010). Levels of CCN2 in biologic fluids correlate with severity of fibrosis in scleroderma, liver cirrhosis and nephropathy. Given the proven role of CCN2 as a measurable serum biomarker in pro-fibrotic diseases and a downstream effector of TGF-β, in this retrospective study we examined CCN2 expression in myelofibrosis. We studied its correlation with clinical response following allogeneic stem cell transplant (ASCT), the only therapeutic modality to date which can consistently reverse fibrosis. METHODSPatients diagnosed with MF at our institution from 1998 to 2015 were identified by diagnostic code (IRB#2013-0896). Bone marrow (BM) specimens at diagnosis and 1 year following ASCT were retrieved. Staging bone marrows from lymphoma patients, read as normal, were used as negative controls. CCN2 localization and expression was assessed by IHC (Abcam 5097). The slides were scored from 0-100% for megakaryocyte cytoplasmic staining by a blinded hematopathologist. RNA was extracted and reverse transcribed from frozen fixed paraffin embedded (FFPE) BM samples using the Qiagen RNeasy FFPE RNA Purification Kit. Assays for CCN1, CCN2 and CCN3 (NOV) and endogenous controls RPLPO and GAPDH were performed using Taqman quantitative PCR assays. mRNA data were analyzed using the software package DataAssist (v3.01; Life Technologies). RESULTSCCN2 expression is upregulated in myelofibrosis compared to healthy bone marrow. mRNA analysis showed a 27 fold increase (p=0.19) in CCN2 mRNA expression in patients with MF when compared to healthy controls. IHC data also showed increased expression in megakaryocytes of MF patients compared to controls (63% vs 40%, p=0.28). Exploratory analysis showed a 36 fold increase in CCN2 mRNA expression in JAK2 negative (n=3) MF patients compared to JAK2 positive (n=7) patients (p=0.06), suggesting expression may depend on the molecular profile. CCN2 expression in the bone marrow of myelofibrosis patients is significantly downregulated at 1 year after allogeneic stem cell transplant. 13 pre-treatment cases of MF were compared with 6 post-transplant cases. The mean percentage of megakaryocyte with cytoplasmic expression of CCN2 by IHC in MF at diagnosis was 63%, compared to 22% in post-transplant specimens, (p= 0.01). mRNA extracted from the post-transplant marrows showed 0.01 fold expression of CCN2 compared to pre-transplant (p= 0.18). This decrease in CCN2 correlated with clinical and pathologic resolution of disease. The average DIPSS score pre-transplant was 2 (range 0-5) which improved to 0 for all patients post-transplant. The mean BM cellularity pre-transplant was 82% (range 50%-95%) and post-transplant was 48% (range 35%-65%). The average decrease in cellularity after transplant was 29%. Reticulin fibrosis ranged from grade 2-3 in the pre-transplant MF bone marrow samples which improved to grade 0-1 post-transplant. CONCLUSIONSCCN2 is a downstream effector of TGF-β and a measurable biomarker of fibrosis in fibroproliferative diseases. We show that CCN2 expression in myelofibrosis decreases significantly after ASCT, suggesting its role as a biomarker of fibrosis in this disease. This paralleled clinical and pathologic resolution of disease. This will need to be validated in a larger number of paired patient samples where in addition to bone marrow expression, serum CCN2 levels will be measured by ELISA. DisclosuresNo relevant conflicts of interest to declare.

Beneficial effects of hydrotherapy on immunity and longevity in a mouse model of social isolation.

Introduction: Hydration and Hydrotherapy is a new type of environmental enrichment strategy, reverting the age-related decline of the homeostatic systems (nervous, endocrine and immune systems), enhancing the neuroendocrine-immune communication and, consequently, improving health and life span. In social species (humans, rodents), loneliness and social isolation are psychological stressors which impair the neuroendocrine- immune communication, increasing morbidity and mortality. Since aging especially affects homeostatic systems and older adults are more vulnerable to feeling lonely or socially isolated, suffering these stressors may aggravate health state in the later stages of life. Objective: The aim of this work was to study the effects of hydration-hydrotherapy on immunity and life span in socially isolated old mice. Method: ICR-CD1 old female mice were maintained in group (n=8) or isolated (n=10) during one month. Then, a group of isolated mice (n=5) was submitted to a 4-weeks hydrotherapy treatment. Peritoneal leukocytes were obtained and macrophages and lymphocytes chemotaxis, and lymphoproliferation in absence (basal) or presence of the mitogens Lipopolyssaccharide and Concanavalin A were analyzed. Mortality was also monitored. Results: Hydration and Hydrotherapy improves lymphocytes chemotaxis and lymphoproliferative response to mitogens (functions reduced with aging), decreases basal lymphoproliferation (which increases with age) and increases life span in socially isolated mice. Conclusions: Hydration-Hydrotherapy seems to be an effective strategy to reverse the immune decline induced by social isolation in elderly as well as to increase longevity.

Platelets and their role in cancer evolution and immune system.

Platelets are anucleate fragments formed from the cytoplasm of megakaryocytes and represent the smallest circulating hematopoietic cells. Thought for almost a century to possess solely hemostatic potentials, platelets actually play a much wider role in tissue regeneration and repair and interact intimately with tumor cells. On the one hand, tumor cells induce platelet aggregation, known to act as the trigger of cancer-associated thrombosis and on the other hand, platelets recruited to the tumor microenvironment interact directly with tumor cells favoring proliferation, and indirectly through the release of angiogenic and mitogenic proteins. Furthermore, platelets are immunosuppressive cells that protect metastatic cancer cells from surveillance by killer cells, nullifying the effects of immunotherapy.

Hypoxia-Inducible Factor 1α Is a Critical Downstream Mediator for Hypoxia-Induced Mitogenic Factor (FIZZ1/RELMα)–Induced Pulmonary Hypertension

Pulmonary hypertension (PH) is characterized by progressive elevation of pulmonary vascular resistance, right ventricular failure, and ultimately death. We have shown that in rodents, hypoxia-induced mitogenic factor (HIMF; also known as FIZZ1 or resistin-like molecule-β) causes PH by initiating lung vascular inflammation. We hypothesized that hypoxia-inducible factor-1 (HIF-1) is a critical downstream signal mediator of HIMF during PH development. In this study, we compared the degree of HIMF-induced pulmonary vascular remodeling and PH development in wild-type (HIF-1α(+/+)) and HIF-1α heterozygous null (HIF-1α(+/-)) mice. HIMF-induced PH was significantly diminished in HIF-1α(+/-) mice and was accompanied by a dysregulated vascular endothelial growth factor-A-vascular endothelial growth factor receptor 2 pathway. HIF-1α was critical for bone marrow-derived cell migration and vascular tube formation in response to HIMF. Furthermore, HIMF and its human homolog, resistin-like molecule-β, significantly increased interleukin (IL)-6 in macrophages and lung resident cells through a mechanism dependent on HIF-1α and, at least to some extent, on nuclear factor κB. Our results suggest that HIF-1α is a critical downstream transcription factor for HIMF-induced pulmonary vascular remodeling and PH development. Importantly, both HIMF and human resistin-like molecule-β significantly increased IL-6 in lung resident cells and increased perivascular accumulation of IL-6-expressing macrophages in the lungs of mice. These data suggest that HIMF can induce HIF-1, vascular endothelial growth factor-A, and interleukin-6, which are critical mediators of both hypoxic inflammation and PH pathophysiology.

ATPS-80ANTI-TUMORIGENESIS OF LENTI-VIRUS sh-HDGF IN RAT C6 GLIOMA MODEL

BACKGROUND: In our previous studies, we found Hepatoma derived growth factor (HDGF) is a mitogenic growth factor in the progression of human glioma. METHODS: In this paper, we study the gliomagenesis role of HDGF in syngenic glioma rat model by Lenti-virus sh-HDGF (LV-shHDGF) infection and tumors growth inhibition was analysis by MRI scanning and western blot analysis. This work was supported by NSC101-2314-B-075B-003-MY2 and VGHKS102-022. RESULTS: We found all glioma tumors growth after implanting but only HDGF knock down tumors had a significant reduction in the tumor size at the 4th-week MRI-scanning. After tumor volume was quantified on serial brain section, we found a 10-folds of reduction in the tumor size was observed in HDGF knock down tumors than scrambles (p < 0.005). By survival analysis, rats with gliomas had a less median survival of 25 days and the HDGF knock down group was still alive from the time point of implanting. According to the pathological analysis, the HDGF knock down tumors presented a significant cell apoptosis and reduction in the Ki67 mitotic index, CD31 angiogenesis index, and ANG-4 that exhibited markedly reduced tumor growth and blood vessel formation than controls. In addition, Western blot analysis showed exogenous HDGF increased the expression of PI3K, phospho-Akt, phospho-FAK, phospho-MDM2, PCNA and transcription factors of Ik-B, NF-kB, cFos, ANG-4, and HIF-a in a dose-dependent manner; however, these tumorigenesis moleculars were significantly decreased in HDGF knock cells. CONCLUSIONS: We concluded that HDGF is a mitogenic growth factor in the progression of glioma and it can be a useful therapeutic target for clinical management of glioma in the future.