237 research outputs found

    Matrix metalloproteinases: expression and regulation in the endometrium during the estrous cycle and at the maternal-conceptus interface during pregnancy in pigs

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    Objective Matrix metalloproteinases (MMPs) are a family of endoproteases produced by various tissues and cells and play important roles in angiogenesis, tissue repair, immune response, and endometrial remodeling. However, the expression and function of MMPs in the pig endometrium during the estrous cycle and pregnancy have not been fully elucidated. Thus, we determined the expression, localization, and regulation of MMP2, MMP8, MMP9, MMP12, and MMP13 in the endometrium throughout the estrous cycle and at the maternal-conceptus interface during pregnancy in pigs. Methods Endometrial tissues during the estrous cycle and pregnancy and conceptus and chorioallantoic tissues during pregnancy were obtained and the expression of MMPs was analyzed. The effects of steroid hormones and cytokines on the expression of MMPs were determined in endometrial explant cultures. Results Expression levels of MMP12 and MMP13 changed during the estrous cycle, while expression of MMP2, MMP9, MMP12, and MMP13 changed during pregnancy. Expression of MMP2, MMP8, and MMP13 mRNAs was cell type-specific at the maternal-conceptus interface. Gelatin zymography showed that enzymatically active MMP2 was present in endometrial tissues. In endometrial explant cultures, estradiol-17β induced the expression of MMP8 and MMP12, progesterone decreased the expression of MMP12, interleukin-1β increased the expression of MMP2, MMP8, MMP9, and MMP13, and interferon-γ increased the expression of MMP2. Conclusion These results suggest that MMPs expressed in response to steroids and cytokines play an important role in the establishment and maintenance of pregnancy by regulating endometrial remodeling and processing bioactive molecules in pigs

    Spatiotemporal expression and regulation of peptidase inhibitor 3 and secretory leukocyte protease inhibitor at the maternal–fetal interface in pigs

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    Objective Two serine protease inhibitors, peptidase inhibitor 3 (PI3) and secretory leukocyte protease inhibitor (SLPI), play important roles in protease inhibition and antimicrobial activity, but their expression, regulation, and function at the maternal–fetal interface in pigs are not fully understood. Therefore, we determined the expression and regulation of PI3 and SLPI in the endometrium throughout the estrous cycle and at the maternal–fetal interface in pigs. Methods Endometrial tissues during the estrous cycle and pregnancy, conceptus tissues during early pregnancy, and chorioallantoic tissues during mid to late pregnancy were obtained, and the expression of PI3 and SLPI was analyzed. The effects of the steroid hormones estradiol-17β (E2) and progesterone (P4) on the expression of PI3 and SLPI were determined in endometrial explant cultures. Results PI3 and SLPI were expressed in the endometrium during the estrous cycle and pregnancy, with higher levels during mid to late pregnancy than during the estrous cycle and early pregnancy. Early-stage conceptuses and chorioallantoic tissues during mid to late pregnancy also expressed PI3 and SLPI. PI3 protein and SLPI mRNA were primarily localized to endometrial epithelia. In endometrial explant cultures, the expression of PI3 was induced by increasing doses of P4, and the expression of SLPI was induced by increasing doses of E2 and P4. Conclusion These results suggest that the PI3 and SLPI expressed in the endometrium and conceptus tissues play an important role in antimicrobial activity for fetal protection against potential pathogens and in blocking protease actions to allow epitheliochorial placenta formation

    Operator Counting for N=2 Chern-Simons Gauge Theories with Chiral-like Matter Fields

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    The localization formula of Chern-Simons quiver gauge theory on S3S^3 nicely reproduces the geometric data such as volume of Sasaki-Einstein manifolds in the large-NN limit, at least for vector-like models. The validity of chiral-like models is not established yet, due to technical problems in both analytic and numerical approaches. Recently Gulotta, Herzog and Pufu suggested that the counting of chiral operators can be used to find the eigenvalue distribution of quiver matrix models. In this paper we apply this method to some vector-like or chiral-like quiver theories, including the triangular quivers with generic Chern-Simons levels which are dual to in-homogeneous Sasaki-Einstein manifolds Yp,k(CP2)Y^{p,k}(\mathbb{CP}^2). The result is consistent with AdS/CFT and the volume formula. We discuss the implication of our analysis.Comment: 23 pages; v2. revised version; v3. corrected typos and clarified argument

    Towards the F-Theorem: N=2 Field Theories on the Three-Sphere

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    For 3-dimensional field theories with {\cal N}=2 supersymmetry the Euclidean path integrals on the three-sphere can be calculated using the method of localization; they reduce to certain matrix integrals that depend on the R-charges of the matter fields. We solve a number of such large N matrix models and calculate the free energy F as a function of the trial R-charges consistent with the marginality of the superpotential. In all our {\cal N}=2 superconformal examples, the local maximization of F yields answers that scale as N^{3/2} and agree with the dual M-theory backgrounds AdS_4 x Y, where Y are 7-dimensional Sasaki-Einstein spaces. We also find in toric examples that local F-maximization is equivalent to the minimization of the volume of Y over the space of Sasakian metrics, a procedure also referred to as Z-minimization. Moreover, we find that the functions F and Z are related for any trial R-charges. In the models we study F is positive and decreases along RG flows. We therefore propose the "F-theorem" that we hope applies to all 3-d field theories: the finite part of the free energy on the three-sphere decreases along RG trajectories and is stationary at RG fixed points. We also show that in an infinite class of Chern-Simons-matter gauge theories where the Chern-Simons levels do not sum to zero, the free energy grows as N^{5/3} at large N. This non-trivial scaling matches that of the free energy of the gravity duals in type IIA string theory with Romans mass.Comment: 66 pages, 10 figures; v2: refs. added, minor improvement

    Superconformal indices of three-dimensional theories related by mirror symmetry

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    Recently, Kim and Imamura and Yokoyama derived an exact formula for superconformal indices in three-dimensional field theories. Using their results, we prove analytically the equality of superconformal indices in some U(1)-gauge group theories related by the mirror symmetry. The proofs are based on the well known identities of the theory of qq-special functions. We also suggest the general index formula taking into account the U(1)JU(1)_J global symmetry present for abelian theories.Comment: 17 pages; minor change

    From Necklace Quivers to the F-theorem, Operator Counting, and T(U(N))

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    The matrix model of Kapustin, Willett, and Yaakov is a powerful tool for exploring the properties of strongly interacting superconformal Chern-Simons theories in 2+1 dimensions. In this paper, we use this matrix model to study necklace quiver gauge theories with {\cal N}=3 supersymmetry and U(N)^d gauge groups in the limit of large N. In its simplest application, the matrix model computes the free energy of the gauge theory on S^3. The conjectured F-theorem states that this quantity should decrease under renormalization group flow. We show that for a simple class of such flows, the F-theorem holds for our necklace theories. We also provide a relationship between matrix model eigenvalue distributions and numbers of chiral operators that we conjecture holds more generally. Through the AdS/CFT correspondence, there is therefore a natural dual geometric interpretation of the matrix model saddle point in terms of volumes of 7-d tri-Sasaki Einstein spaces and some of their 5-d submanifolds. As a final bonus, our analysis gives us the partition function of the T(U(N)) theory on S^3.Comment: 3 figures, 41 pages; v2 minor improvements, refs adde

    F-Theorem without Supersymmetry

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    The conjectured F-theorem for three-dimensional field theories states that the finite part of the free energy on S^3 decreases along RG trajectories and is stationary at the fixed points. In previous work various successful tests of this proposal were carried out for theories with {\cal N}=2 supersymmetry. In this paper we perform more general tests that do not rely on supersymmetry. We study perturbatively the RG flows produced by weakly relevant operators and show that the free energy decreases monotonically. We also consider large N field theories perturbed by relevant double trace operators, free massive field theories, and some Chern-Simons gauge theories. In all cases the free energy in the IR is smaller than in the UV, consistent with the F-theorem. We discuss other odd-dimensional Euclidean theories on S^d and provide evidence that (-1)^{(d-1)/2} \log |Z| decreases along RG flow; in the particular case d=1 this is the well-known g-theorem.Comment: 34 pages, 2 figures; v2 refs added, minor improvements; v3 refs added, improved section 4.3; v4 minor improvement

    The Large N Limit of Toric Chern-Simons Matter Theories and Their Duals

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    We compute the large N limit of the localized three dimensional free energy of various field theories with known proposed AdS duals. We show that vector-like theories agree with the expected supergravity results, and with the conjectured F-theorem. We also check that the large N free energy is preserved by the three dimensional Seiberg duality for general classes of vector like theories. Then we analyze the behavior of the free energy of chiral-like theories by applying a new proposal. The proposal is based on the restoration of a discrete symmetry on the free energy before the extremization. We apply this procedure at strong coupling in some examples and we discuss the results. We conclude the paper by proposing an alternative geometrical expression for the free energy.Comment: 40 pages, 7 figures, using jheppub.sty, references adde

    Refined Checks and Exact Dualities in Three Dimensions

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    We discuss and provide nontrivial evidence for a large class of dualities in three-dimensional field theories with different gauge groups. We match the full partition functions of the dual phases for any value of the couplings to underpin our proposals. We focus on two classes of models. The first class, motivated by the AdS/CFT conjecture, consists of necklace U(N) quiver gauge theories with non chiral matter fields. We also consider orientifold projections and establish dualities among necklace quivers with alternating orthogonal and symplectic groups. The second class consists of theories with tensor matter fields with free theory duals. In most of these cases the R-symmetry mixes with IR accidental symmetries and we develop the prescription to include their contribution into the partition function and the extremization problem accordingly.Comment: 38 pages, 3 figure, using jheppu

    Holographic Duals of D=3 N=4 Superconformal Field Theories

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    We find the warped AdS_4 x K type-IIB supergravity solutions holographically dual to a large family of three dimensional \cN=4 superconformal field theories labeled by a pair (\rho,\hat\rho) of partitions of N. These superconformal theories arise as renormalization group fixed points of three dimensional mirror symmetric quiver gauge theories, denoted by T^{\rho}_{\hat \rho}(SU(N)) and T_{\rho}^{\hat \rho}(SU(N)) respectively. We give a supergravity derivation of the conjectured field theory constraints that must be satisfied in order for these gauge theories to flow to a non-trivial supersymmetric fixed point in the infrared. The exotic global symmetries of these superconformal field theories are precisely realized in our explicit supergravity description.Comment: 33 pages, LaTeX; added a comment mentioning that these solutions have all moduli fixed; typos corrected; references adde
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