Antiretroviral drug therapy (ART) effectively suppresses replication of both the immunodeficiency viruses, human (HIV) and simian (SIV); however, virus rebounds soon after ART is withdrawn. SIV-infected monkeys were treated with a 90-day course of ART initiated at 5 weeks post infection followed at 9 weeks post infection by infusions of a primatized monoclonal antibody against the α4β7 integrin administered every 3 weeks until week 32. These animals subsequently maintained low to undetectable viral loads and normal CD4+ T cell counts in plasma and gastrointestinal tissues for more than 9 months, even after all treatment was withdrawn. This combination therapy allows macaques to effectively control viremia and reconstitute their immune systems without a need for further therapy.

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In the uterus, the formation of new maternal blood vessels in the stromal compartment at the time of embryonic implantation is critical for the establishment and maintenance of pregnancy. Although uterine angiogenesis is known to be influenced by the steroid hormones estrogen (E) and progesterone (P), the underlying molecular pathways remain poorly understood. Here, we report that the expression of connexin 43 (Cx43), a major gap junction protein, is markedly enhanced in response to E in uterine stromal cells surrounding the implanted embryo during the early phases of pregnancy. Conditional deletion of the Cx43 gene in these stromal cells and the consequent disruption of their gap junctions led to a striking impairment in the development of new blood vessels within the stromal compartment, resulting in the arrest of embryo growth and early pregnancy loss. Further analysis of this phenotypical defect revealed that loss of Cx43 expression resulted in aberrant differentiation of uterine stromal cells and impaired production of several key angiogenic factors, including the vascular endothelial growth factor (Vegf). Ablation of CX43 expression in human endometrial stromal cells in vitro led to similar findings. Collectively, these results uncovered a unique link between steroid hormone-regulated cell-cell communication within the pregnant uterus and the development of an elaborate vascular network that supports embryonic growth. Our study presents the first evidence that Cx43-type gap junctions play a critical and conserved role in modulating stromal differentiation, and regulate the consequent production of crucial paracrine signals that control uterine neovascularization during implantation.

Tobacco use is the most important risk factor for the development of lung carcinoma. One characteristic shared by tobacco-related lung diseases is altered lung connective tissue content and composition. In particular, tobacco results in increased expression of fibronectin (FN), a matrix glycoprotein implicated in lung development, injury and repair and in tumor cell invasion. We hypothesized that excessive deposition of FN in lung might promote lung carcinoma cell proliferation. Consistent with this hypothesis, we found that FN stimulated human lung carcinoma cell proliferation and diminished apoptosis in vitro, and that this effect was mediated through the integrin ␣5␤1 and associated with upregulation of cyclooxygenase-2 (COX-2) mRNA and protein expression, and increased prostaglandin E 2 (PGE 2 ) biosynthesis. Key words: fibronectin; COX-2; human lung carcinoma cells; cAMP response element; C/EBP; NF-IL6Lung carcinoma is one of the most common malignant tumors in the world and is the leading cause of carcinoma death in men and women in the United States. 1 Despite recent advances in understanding the molecular biology of lung carcinoma and the introduction of multiple new chemotherapeutic agents for its treatment, its dismal 5-year survival rate (Ͻ 15%) has not changed substantially. 2 Tobacco use is the most important risk factor for the development of lung carcinoma. 3 Also, patients with emphysema, idiopathic pulmonary fibrosis and other lung diseases characterized by dramatic alterations in lung architecture are at increased risk of developing lung carcinoma. 3 One characteristic shared by tobacco-related and other chronic lung diseases is altered lung connective tissue content and composition. In particular, they are associated with increased expression and deposition in lung of fibronectin (FN), a 250 Kd heterodimeric extracellular matrix glycoprotein implicated in physiologic events during embryogenesis, angiogenesis, thrombosis and inflammation. 4,5 FN has also been implicated in carcinogenesis. Studies of solid human tumors have shown that among the early signs of malignant transformation is the fragmentation of pericellular FN that is concomitant with an increase in FN deposition in the peritumoral stroma. 6 FN has also been shown to be expressed in several carcinoma cell types. 7-9 Nanki et al. 10 showed that oncofetal FN is expressed in lung carcinoma cells, especially in non small cell lung carcinoma (NSCLC) cell lines. Jakowlew et al. 11 reported that treatment of NSCLC cells with TGF-␤1 resulted in a persistent increase in protein and mRNA expression for FN. The adhesion of lung carcinoma cells to FN enhances tumorigenicity and confers resistance to apoptosis induced by standard chemotherapeutic agents. 12 Despite the above, a link between FN and lung carcinoma cell growth has not been firmly established. Furthermore, the mechanisms by which FN exerts its effects on lung tumors remain unelucidated.Many of the biologic effects of FN are mediated via the integrin receptor ␣5␤1. 13,14 This hetero...

Like tumor metastases, endometriotic implants require neovascularization to proliferate and invade into ectopic sites within the host. Endometrial tissue, with its robust stem cell populations and remarkable regenerative capabilities, is a rich source of proangiogenic factors. Among the most potent and extensively studied of these proteins, vascular endothelial growth factor has emerged as a critical vasculogenic regulator in endometriosis. Accordingly, angiogenesis of the nascent endometriotic lesion has become an attractive target for novel medical therapeutics and strategies to inhibit vascular endothelial growth factor action. Vascular endothelial growth factor gene regulation in endometrial and endometriosis cells by nuclear receptors, other transcription factors, and also by infiltrating immune cells is emphasized. New data showing that oxidative and endoplasmic reticulum stress increase vascular endothelial growth factor expression are provided. Finally, we review the clinical implications of angiogenesis in this condition and propose potential antiangiogenic therapies that may become useful in the control or eradication of endometriotic lesions. Keywords VEGF; uterus; endothelial Etiology of EndometriosisEndometriosis is a common gynecological disorder defined by the proliferation of endometrial glands and stroma outside the confines of the uterine cavity. The disease affects 5% to 10% of all reproductive-aged women and the prevalence rises to 20% to 50% in infertile women. Genetic factors influence susceptibility to endometriosis; however, the mode of hereditary transmission is complex and likely multifactorial. 1 Sib-pair linkage analyses in 1176 families of affected British and Australian women identified a susceptibility locus on chromosome 10q26 locus. 2 A number of other genetic aberrancies, particularly single nucleotide polymorphisms in relevant nuclear receptors (eg, estrogen receptor-α 3 and estrogen receptor-β 4 ), cytokines, 5 and even in the vascular endothelial growth factor (VEGF) coding sequence per se in Korean 6 and South Indian populations 7 are associated with an increased odds ratio of endometriosis prevalence.Arguments persist over the histogenic etiology of endometriosis; however, the implantation hypothesis put forward by Sampson more than 80 years ago is the most widely accepted. 8 Retrograde menstruation, 9 with subsequent intraperitoneal spillage 10 and mesothelial

Purpose: The peroxisome proliferator-activated receptor ␥ (PPAR␥), a ligand-dependent transcription factor belonging to the family of nuclear receptors, has been implicated in the regulation of cell growth and differentiation although the exact mechanism(s) of this activity has not been elucidated. In this study, we explored the role of PPAR␥ signaling on the control of gene expression of the cycledependent kinase inhibitor p21 in human lung carcinoma cells.Experimental Design: Using several human lung carcinoma cell lines (small and non-small carcinoma cells), we assayed for cell growth inhibition and apoptosis induction. We also assayed for p21 mRNA and protein expression by reverse transcription-PCR, real-time reverse transcription-PCR, and Western blot analysis. Nuclear protein binding activities to three response elements located in the p21 promoter [nuclear factor (NF)-B, Sp1, and NF-interleukin 6 (IL6) CAAT/enhancer binding protein (C/EBP)] were measured by gel mobility shift assays. We used transient transfection assays with p21 promoter reporter gene constructs to determine the transcriptional regulation by PPAR␥ ligands. Finally, by using p21 antisense oligonucleotides, we tested the link between PPAR␥ activation and p21 signaling in cell growth inhibition assays and by Western blot analysis.Results: We showed that the PPAR␥ ligands PGJ2 and ciglitazone inhibit the growth and induce the apoptosis of several human lung carcinoma cell lines, whereas the PPAR␣ agonist WY14643 has little effect. Treatment of lung carcinoma cells with the PPAR␥ ligands PGJ2, ciglitazone, troglizaone, and GW1929 elevated p21 mRNA and protein levels and reduced cyclin D1 mRNA levels. These results were supported by transient transfection assays, which indicated that PPAR␥ ligands increased p21 gene promoter activity in human lung carcinoma cells. In addition, p21 antisense oligonucleotides inhibited PPAR␥ ligand-induced p21 protein expression and significantly blocked lung carcinoma cell growth inhibition induced by PPAR␥ ligands. Finally, electrophoresis mobility shift experiments demonstrated that PPAR␥ ligands increased the nuclear binding activities of Sp1 and NF-IL6 (C/EBP), two transcription factors with regulatory elements in the promoter region of the p21 gene.Conclusion: PPAR␥ ligands inhibit human lung carcinoma cell growth and induce apoptosis by stimulating the cyclin-dependent kinase inhibitor p21 and by reducing cyclin D1 gene expression. The induction of p21 gene expression by PPAR␥ ligands may be mediated through increased Sp1-and NF-IL6 (C/EBP)-dependent transcriptional activation. These observations unveil a mechanism for p21 gene regulation in lung carcinoma that represents a potential target for therapy.

Our objective has been to establish a pro-angiogenic role for exosomes in endometriosis and to determine whether a differential expression profile of cellular and exosomal microRNAs (miRNAs) exists in endometriosis. We performed an in vitro study of human primary endometrial stromal cells (ESCs) and human umbilical vein endothelial cells (HUVECs). We isolated and characterized exosomes from ESCs from five endometriosis patients and five phase-matched controls. Exosomes were characterized by transmission electron microscopy and NanoSight technology. MiRNA was assessed by deep sequencing and reverse transcription with quantitative polymerase chain reaction. Exosome uptake studies were achieved by means of confocal microscopy. The pro-angiogenic experiments were executed by treating HUVECs with ESC-derived exosomes. We observed differential profiles of exosomal miRNA expression between exosomes derived from endometriosis lesion cells and diseased eutopic stromal cells compared with exosomes derived from control ESCs. We also demonstrated autocrine cellular uptake of exosomes and paracrine functional angiogenic effects of exosomes on HUVECs. The results of this study support the hypothesis that exosomes derived from ESCs play autocrine/paracrine roles in the development of endometriosis, potentially modulating angiogenesis. The broader clinical implications are that Sampson’s theory of retrograde menstruation possibly encompasses the finding that exosomes work as intercellular communication modulators in endometriosis.

Human natural killer (NK) cells in peripheral blood spontaneously recognize and kill a wide variety of target cells. It has been suggested that ion channels are involved in the killing process because there is a Ca-dependent stage and because killing by presensitized cytotoxic T lymphocytes, which in many respects resembles NK killing, is associated with changes in K and Na transport in the target cell. However, no direct evidence exists for ion channels in NK cells or in their target cells. Using the whole-cell variation of the patch-clamp technique, we found a voltage-dependent potassium (K+) current in NK cells. The K+ current was reduced in a dose-dependent manner by the K-channel blockers 4-aminopyridine and quinidine and by the traditional Ca-channel blockers verapamil and Cd2 . We tested the effects of ionchannel blockers on killing of two commonly used target cell lines: K562, which is derived from a human myeloid leukemia, and U937, which is derived from a human histiocytic leukemia.Killing of K562 target cells, determined in a standard 51Cr-release assay, was inhibited in a dose-dependent manner by verapamil, quinidine, Cd2+, and 4-aminopyridine at concentrations comparable to those that blocked the K+ current in NK cells. In K562 target cells only a voltage-dependent Na' current was found and it was blocked by concentrations of tetrodotoxin that had no effect on killing. Killing of U937 target cells was also inhibited by the two ion-channel blockers tested, quinidine and verapamil. In this cell line only a small K+ current was found that was similar to the one in NK cells. We could not rind any evidence of a Ca21 current in target cells or in NK cells; therefore, our results cannot explain the Ca dependence of killing. Our findings show that there are K channels in NK cells and that these channels play a necessary role in the killing process. In contrast, the endogenous channel type in the target cell is probably not a factor in determining target cell sensitivity to natural killing.