WISP1, a Pro-mitogenic, Pro-survival Factor, Mediates Tumor Necrosis Factor-�� (TNF-��)-stimulated Cardiac Fibroblast Proliferation but Inhibits TNF-��-induced Cardiomyocyte Death

WNT1-inducible signaling pathway protein-1 (WISP1), a member of the CYR61/CTGF/Nov family of growth factors, can mediate cell growth, transformation, and survival. Previously we demonstrated that WISP1 is up-regulated in post-infarct heart, stimulates cardiac fibroblast proliferation, and is induced by the proinflammatory cytokine tumor necrosis factor-α (TNF-α). Here we investigated (i) the localization of TNF-α and WISP1 in post-infarct heart, (ii) the mechanism of TNF-α-mediated WISP1 induction in primary human cardiac fibroblasts (CF), (iii) the role of WISP1 in TNF-α-mediated CF proliferation and collagen production, and (iv) the effects of WISP1 on TNF-α-mediated cardiomyocyte death. TNF-α and WISP1 expressions were increased in the border zones and non-ischemic remote regions of the post-ischemic heart. In CF, TNF-α potently induced WISP1 expression in cyclic AMP response element-binding protein (CREB)-dependent manner. TNF-α induced CREB phosphorylation in vitro and DNA binding and reporter gene activities in vivo. TNF-α induced CREB activation via ERK1/2, and inhibition of ERK1/2 and CREB blunted TNF-α-mediated WISP1 induction. Most importantly, WISP1 knockdown attenuated TNF-α stimulated collagen production and CF proliferation. Furthermore, WISP1 attenuated TNF-α-mediated cardiomyocyte death, thus demonstrating pro-mitogenic and pro-survival effects for WISP1 in myocardial constituent cells. Our results suggest that a TNF-α/WISP1 signaling pathway may contribute to post-infarct cardiac remodeling, a condition characterized by fibrosis and progressive cardiomyocyte loss.Acute myocardial infarction (MI)² is a major cause of morbidity and mortality worldwide. After acute MI, the two principal determinants of patient outcome are myocardial infarct size and the extent of left ventricular (LV) remodeling (1–3). Infarct size is determined during the acute phase immediately post-MI. LV remodeling on the other hand is a continuous and maladaptive process characterized by progressive left ventricular hypertrophy, fibrosis, ventricular dilatation, and by the gradual deterioration of cardiac performance, leading ultimately to congestive heart failure (1–3).Numerically, fibroblasts are the major cell type in the heart, but they constitute a smaller total volume compared with cardiomyocytes (4). Fibroblasts are associated primarily with modulation of extracellular matrix and tissue healing/repair (4–6). Fibroblasts secrete collagens, fibrillins, fibronectin, laminin, and matrix metalloproteinases and, thus, are responsible for the maintenance of connective tissue homeostasis (4–7). We and others have shown that primary cardiac fibroblasts also produce various cytokines, chemokines, and growth factors (4–6, 8, 9), which tightly regulate the physiological function of the cells. Under pathological conditions, however, where the expression of cytokines and growth factors is significantly altered, the fibroblasts can undergo differentiation, migration, and proliferation, resulting in pathological fibrosis because of excessive accumulation of collagens and other ECM proteins (4–6).The six members of the CCN (CYR61/CTGF/Nov) family of growth factors (Cyr61 (cysteine-rich 61, CCN1), CTGF (connective tissue growth factor, CCN2), Nov (nephroblastoma-overexpressed, CCN3), WISP1 (WNT1-inducible signaling pathway protein-1, CCN4), WISP2 (CCN5), and WISP3 (CCN6)) are involved in a number of cellular processes, including adhesion, migration, and proliferation (10–12). Although their roles in angiogenesis and oncogenesis are well characterized, with the exception of CTGF, their precise contribution to myocardial remodeling is unknown. Recently we demonstrated that whereas WISP1 is expressed in the heart at low basal levels, permanent occlusion of the left anterior descending coronary artery significantly up-regulates its expression in the non-ischemic myocardium (13). Furthermore, we have found that WISP1 exerts both pro-hypertrophic and pro-mitogenic effects in vitro, stimulating Akt-dependent cardiomyocyte growth, as well as collagen synthesis and fibroblast proliferation (13). Because cardiomyocyte hypertrophy and fibroblast proliferation play central roles in remodeling and WISP1 regulates these two critical processes, it is plausible that WISP1 also mediates cardiac remodeling after myocardial ischemia, infarction, and inflammation. However, the mechanisms involved in the induction and regulation of WISP1 under these conditions have not been well characterized.The proinflammatory cytokine tumor necrosis factor (TNF)-α is expressed at low basal levels in the normal myocardium but is significantly up-regulated after infection, inflammation, and injury (14, 15). Although low levels are considered cytoprotective (16, 17), aberrant expression of TNF-α during myocardial ischemic injury and inflammation induces cardiomyocyte death, hypertrophy of surviving cardiomyocytes, contractile dysfunction, fibroblast proliferation, fibrosis, and adverse remodeling (14–17). TNF-α exerts its biological effects via two cell surface receptors, TNFR1 (55 kDa) and TNFR2 (75 kDa) (18). TNFR1, which is more abundantly expressed in the heart, appears to be the main signaling receptor for TNF-α and is implicated in transmitting its deleterious effects (18). On the other hand, signaling through TNFR2 appears to exert a protective effect in the heart (18, 19). Of note, all myocardial constituent cells, including fibroblasts, express both TNFR1 and TNFR2 and, therefore, are targets of TNF-α.We have recently demonstrated that TNF-α induces WISP1 expression in cardiomyocytes (13). However, neither its localization in post-infarct myocardium, its role in TNF-α-mediated cardiac fibroblast (CF) proliferation and collagen production, nor its effects on TNF-α-mediated cardiomyocyte death are known. Our results show that both TNF-α and WISP1 are localized in the border zone and the non-infarct remote region in post-infarct myocardium. Furthermore, TNF-α induces WISP1 expression in CF via a TNFR2/MEK1/ERK1/2/CREB pathway and stimulates fibroblast collagen production in part via WISP1. In addition, WISP1 exerts pro-survival effects in cardiomyocytes, antagonizing TNF-α-mediated cardiomyocyte death. Collectively, these results indicate that WISP1 exerts pro-mitogenic and pro-survival effects in cardiac cell type-specific manner, and TNF-α/WISP1 signaling may be an important contributing mechanism in post-infarct cardiac remodeling.     

Isoelectric Point Based Dual Sensitive Peptide-Drug Conjugate Prodrug to Target Solid Tumors

International Journal of Peptide Research and Therapeutics - Anticancer drugs (Doxorubicin, Methotrexate, Daunorubicin, etc.,) shows excellent activity on killing cancer cells, equal amount of...     

Inter retrotransposon based genetic diversity and phylogenetic analysis among the Musa germplasm accessions

In the present investigation, the insertional polymorphisms of retro-elements were studied in the Musa germplasm available at ICAR-NRCB field gene bank using IRAP markers. The maximum number of polymorphic bands were produced by the primer pair Nikita and LTR 6150 (48) followed by LTR 6149 and 3′LTR (47) and minimum of 35 bands were produced by the primer pair Sukkula and LTR 6150. The bands produced were scored as 0 (absent) and 1 (present) and the resultant binary data was subjected to diversity analysis. The dendrogram consisted of two major clusters with members of Eumusa and Rhodochlamys in one indicating their genetic closeness and members of the genus Ensete in another cluster. Results of principal coordinate analysis were congruent to those obtained in hierarchial cluster analysis. The molecular markers used in this study could reveal intra and inter-group diversity among the Musa germplasm accessions with similarity co-efficient ranging from 0.41 to 0.99. IRAP marker system has performed excellently clustering the accessions based on both genomic and subgroup levels. The entire germplasm was found to be robust with no duplications indicating the diverse group of accessions available at ICAR-NRCB field gene bank. It has also exhibited high polymorphism and hence could be effectively used to detect the genetic relatedness among diverse genome of Musa.     

TRAF3IP2 mediates interleukin-18-induced cardiac fibroblast migration and differentiation

TRAF3IP2 is a cytoplasmic adapter protein and an upstream regulator of IKK/NF-κB and JNK/AP-1. Here we demonstrate for the first time that the proinflammatory cytokine interleukin (IL)-18 induces TRAF3IP2 expression in primary cardiac fibroblasts (CF) in a Nox4/hydrogen peroxide-dependent manner. Silencing TRAF3IP2 using a phosphorothioated, 2′-O-methyl modified, cholesterol-tagged TRAF3IP2 siRNA duplex markedly attenuated IL-18-induced NF-κB and AP-1 activation and CF migration. Using co-IP/IB and co-localization experiments, we show that Nox4 physically associates with IL-18 receptor proteins, and IL-18 enhances their binding. Further, IL-18 promotes fibroblast to myofibroblast transition, as evidenced by enhanced α-smooth muscle actin expression, types 1 and 3 collagen induction, and soluble collagen secretion, via TRAF3IP2. These results indicate that TRAF3IP2 is a critical intermediate in IL-18-induced CF migration and differentiation in vitro. TRAF3IP2 could serve as a potential therapeutic target in cardiac fibrosis and adverse remodeling in vivo.     

Interleukin-17A stimulates cardiac fibroblast proliferation and migration via negative regulation of the dual-specificity phosphatase MKP-1/DUSP-1

The dual-specificity mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) inactivates MAP kinases by dephosphorylation. Here we show that the proinflammatory cytokine interleukin (IL)-17A induces adult mouse primary cardiac fibroblast (CF) proliferation and migration via IL-17 receptor A//IL-17 receptor C-dependent MKP-1 suppression, and activation of p38 MAPK and ERK1/2. IL-17A mediated p38 MAPK and ERK1/2 activation is inhibited by MKP-1 overexpression, but prolonged by MKP-1 knockdown. IL-17A induced miR-101 expression via PI3K/Akt, and miR-101 inhibitor reversed MKP-1 down regulation. Importantly, MKP-1 knockdown, pharmacological inhibition of p38 MAPK and ERK1/2, or overexpression of dominant negative MEK1, each markedly attenuated IL-17A-mediated CF proliferation and migration. Similarly, IL-17F and IL-17A/F heterodimer that also signal via IL-17RA/IL-17RC, stimulated CF proliferation and migration. These results indicate that IL-17A stimulates CF proliferation and migration via Akt/miR-101/MKP-1-dependent p38 MAPK and ERK1/2 activation. These studies support a potential role for IL-17 in cardiac fibrosis and adverse myocardial remodeling.     

Clinical implication of pretreatment neutrophil to lymphocyte ratio in soft tissue sarcoma

Introduction: Elevated neutrophil to lymphocyte ratio has been identified as a prognostic indicator in malignancies whereas; its association with extremity and trunk soft tissue sarcoma remain unclear. The aim of this study is to determine the utility of full blood neutrophil lymphocyte ratio (NLR) in preoperative diagnosis and its predictive value for survival in patients managed for soft tissue sarcoma of the trunk and extremities. Method: 223 patients who presented with a soft tissue tumor were retrospectively reviewed. The study period was from January 2002-December 2009. Preoperative NLR as well as demographics, clinical and histopathological data were analysed. Results: Full blood NLR was significantly higher in patient with a soft tissue sarcoma compared to benign soft tissue tumors (p < 0.001). Cox regression analysis demonstrated that elevated NLR >5 (p < 0.05) may be an adverse prognostic factor for Overall Survival. Conclusion: The preoperative NLR is a simple, investigation predicting the preoperative diagnosis of a soft tissue sarcoma and a predictor of worse overall survival for patient with a soft tissue sarcoma.     

Effects of prednisolone and dexamethasone on (pro)insulin biosynthesis and insulin release by rat islets of Langerhans

Administration of either prednisolone or dexamethasone (10 mg/kg body wt/day/oral) to rats for 21 days resulted in inhibition of (pro)insulin biosynthesis and immunoreactive insulin release by isolated islets. A gradual reversal of prednisolone's effect was obtained after exposing islets to increasing glucose concentrations but glucose challenges failed to influence dexamethasone's effect.     

Allotment of carbon is responsible for disorders in proteins

Sequence stretches in proteins that do not fold into a form are referred as disordered regions. Databases like Disport describe disordered regions in proteins and web servers like PrDOS and DisEMBL, facilitate the prediction of disordered regions. These studies are often based on residue level features. Here, we describe proteins with disordered regions using carbon content and distributions. The distribution pattern for proteins with disordered regions is different from those that do not show disordered regions.