Polyphenols: Role in Modulating Immune Function and Obesity

Polyphenols, long-used components of medicinal plants, have drawn great interest in recent years as potential therapeutic agents because of their safety, efficacy, and wide range of biological effects. Approximately 75% of the world's population still use plant-based medicinal compounds, indicating the ongoing significance of phytochemicals for human health. This study emphasizes the growing body of research investigating the anti-adipogenic and anti-obesity functions of polyphenols. The functions of polyphenols, including phenylpropanoids, flavonoids, terpenoids, alkaloids, glycosides, and phenolic acids, are distinct due to changes in chemical diversity and structural characteristics. This review methodically investigates the mechanisms by which naturally occurring polyphenols mediate obesity and metabolic function in immunomodulation. To this end, hormonal control of hunger has the potential to inhibit pro-obesity enzymes such as pancreatic lipase, the promotion of energy expenditure, and the modulation of adipocytokine production. Specifically, polyphenols affect insulin, a hormone that is essential for regulating blood sugar, and they also play a role, in part, in a complex web of factors that affect the progression of obesity. This review also explores the immunomodulatory properties of polyphenols, providing insight into their ability to improve immune function and the effects of polyphenols on gut health, improving the number of commensal bacteria, cytokine production suppression, and immune cell mediation, including natural killer cells and macrophages. Taken together, continuous studies are required to understand the prudent and precise mechanisms underlying polyphenols' therapeutic potential in obesity and immunomodulation. In the interim, this review emphasizes a holistic approach to health and promotes the consumption of a wide range of foods and drinks high in polyphenols. This review lays the groundwork for future developments, indicating that the components of polyphenols and their derivatives may provide the answer to urgent worldwide health issues. This compilation of the body of knowledge paves the way for future discoveries in the global treatment of pressing health concerns in obesity and metabolic diseases.

SARS-CoV-2 Spike Protein Stimulates Macropinocytosis in Murine and Human Macrophages via PKC-NADPH Oxidase Signaling

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While recent studies have demonstrated that SARS-CoV-2 may enter kidney and colon epithelial cells by inducing receptor-independent macropinocytosis, it remains unknown whether this process also occurs in cell types directly relevant to SARS-CoV-2-associated lung pneumonia, such as alveolar epithelial cells and macrophages. The goal of our study was to investigate the ability of SARS-CoV-2 spike protein subunits to stimulate macropinocytosis in human alveolar epithelial cells and primary human and murine macrophages. Flow cytometry analysis of fluid-phase marker internalization demonstrated that SARS-CoV-2 spike protein subunits S1, the receptor-binding domain (RBD) of S1, and S2 stimulate macropinocytosis in both human and murine macrophages in an angiotensin-converting enzyme 2 (ACE2)-independent manner. Pharmacological and genetic inhibition of macropinocytosis substantially decreased spike-protein-induced fluid-phase marker internalization in macrophages both in vitro and in vivo. High-resolution scanning electron microscopy (SEM) imaging confirmed that spike protein subunits promote the formation of membrane ruffles on the dorsal surface of macrophages. Mechanistic studies demonstrated that SARS-CoV-2 spike protein stimulated macropinocytosis via NADPH oxidase 2 (Nox2)-derived reactive oxygen species (ROS) generation. In addition, inhibition of protein kinase C (PKC) and phosphoinositide 3-kinase (PI3K) in macrophages blocked SARS-CoV-2 spike-protein-induced macropinocytosis. To our knowledge, these results demonstrate for the first time that SARS-CoV-2 spike protein subunits stimulate macropinocytosis in macrophages. These results may contribute to a better understanding of SARS-CoV-2 infection and COVID-19 pathogenesis.

Inhibition of microRNA-34c reduces detrusor ROCK2 expression and urinary bladder inflammation in experimental cystitis

Interstitial cystitis (IC), also called painful bladder syndrome (PBS), is 2 to 5 times more common in women than in men, yet its cause and pathogenesis remain unclear. In our study using the cyclophosphamide (CYP)-induced mouse model of cystitis, histological evaluation of the urinary bladder (UB) lamina propria (LP) showed immune cell infiltrations, indicating moderate to severe inflammation. In this study, we noticed a differential expression of a subset of microRNAs (miRs) in the UB cells (UBs) of CYP-induced cystitis as compared to the control. UB inflammatory scores and inflammatory signaling were also elevated in CYP-induced cystitis as compared to control. We identified eight UBs miRs that exhibited altered expression after CYP induction and are predicted to have a role in inflammation and smooth muscle function (miRs-34c-5p, -34b-3p, -212-3p, -449a-5p, -21a-3p, -376b-3p, -376b-5p and - 409-5p). Further analysis using ELISA for inflammatory markers and real-time PCR (RT-PCR) for differentially enriched miRs identified miR-34c as a potential target for the suppression of UB inflammation in cystitis. Blocking miR-34c by antagomir ex vivo reduced STAT3, TGF-β1, and VEGF expression in the UBs, which was induced during cystitis as compared to control. Interestingly, miR-34c inhibition also downregulated ROCK2 but elevated ROCK1 expression in bladder and detrusor cells. Thus, the present study shows that targeting miR-34c can mitigate the STAT3, TGF-β, and VEGF, inflammatory signaling in UB, and suppress ROCK2 expression in UBs to effectively suppress the inflammatory response in cystitis. This study highlights miR-34c as a potential biomarker and/or serves as the basis for new therapies for the treatment of cystitis.

Resveratrol and its analogs suppress HIV replication, oxidative stress, and inflammation in macrophages

Objectives

HIV suppression in brain viral reservoirs, especially macrophages, and microglia is critical to suppress HIV neuropathogenesis and subsequently HIV-associated neurocognitive disorders (HAND). Since most antiretroviral therapy (ART) drugs do not achieve optimal therapeutic concentrations in the brain and can cause neurotoxicity, an alternative/adjuvant therapy is needed to suppress HIV neuropathogenesis. In this study, our objectives were to examine the anti-HIV, antioxidant, and anti-inflammatory potential of resveratrol (RES) and its synthetic analogs 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol} (TIMBD) and 4-(E)-{(4-hydroxyphenylimino)-methylbenzene,1,2-diol} (HPIMBD) in HIV-infected macrophages.

Methods

We used HIV replication (viral load), oxidative stress (reactive oxygen species and antioxidant enzymes), and inflammatory response (pro- and anti-inflammatory cytokines/chemokines) assays to achieve the objectives of the study.

Results

Our results showed that RES and its analogs HPIMBD and TIMBD at 25 µM concentration significantly decrease HIV replication in both primary monocyte-derived macrophages and U1-differentiated macrophages. Moreover, RES and its analogs do not induce any cytotoxicity for up to 3 days in these cells. Further, treatment with RES and TIMBD (25 µM) also reduced the levels of reactive oxygen species without affecting the expression of antioxidant enzymes, SOD1, and catalase in U1 macrophages. Besides, RES and HPIMBD treatment inhibited the proinflammatory cytokines and chemokines in U1 macrophages, which was associated with decreased levels of anti-inflammatory cytokines. Importantly, our western blot experiments show that RES also decreases cellular proinflammatory cytokine IL-1β, which is usually elevated in both myeloid and neuronal cells upon HIV infection.

Conclusions

Taken together, our results suggest that RES and/or its analogs are important adjuvants that may be used not only to suppress HIV but also oxidative stress and inflammation in brain viral reservoirs.

Nanocarrier-mediated curcumin delivery: An adjuvant strategy for CNS disease treatment

Neurological disorders are a major global challenge, which counts for a substantial slice of disease burden around the globe. In these, the challenging landscape of central nervous system (CNS) diseases, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and neuro-AIDS, demands innovative and novel therapeutic approaches. Curcumin, a versatile natural compound with antioxidant and anti-inflammatory properties, shows great potential as a CNS adjuvant therapy. However, its limited bioavailability and suboptimal permeability to the blood-brain barrier (BBB) hamper the therapeutic efficacy of curcumin. This review explores how nanocarrier facilitates curcumin delivery, which has shown therapeutic efficacy for various non-CNS diseases, for example, cancers, and can also revolutionize the treatment outcomes in patients with CNS diseases. Toward this, intranasal administration of curcumin as a non-invasive CNS drug delivery route can also aid its therapeutic outcomes as an adjuvant therapy for CNS diseases. Intranasal delivery of nanocarriers with curcumin improves the bioavailability of curcumin and its BBB permeability, which is instrumental in promoting its therapeutic potential. Furthermore, curcumin's inhibitory effect on efflux transporters will help to enhance the BBB and cellular permeability of various CNS drugs. The therapeutic potential of curcumin as an adjuvant has the potential to yield synergistic effects with CNS drugs and will help to reduce CNS drug doses and improve their safety profile. Taken together, this approach holds a promise for reshaping CNS disease management by maximizing curcumin's and other drugs' therapeutic benefits.

Hydrogen sulfide donor activates AKT-eNOS signaling and promotes lymphatic vessel formation

The lymphatic network is pivotal for various physiological functions in the human body. Accumulated evidence supports the role of therapeutic lymphangiogenesis in the treatment of several pathologies. Endogenous gasotransmitter, hydrogen sulfide (H2S) has been extensively studied for its potential as a pro-angiogenic factor and vascular function modulator. However, the role of H2S in governing lymphatic vessel formation, and underlying molecular mechanisms are understudied. The present study was designed to investigate the effects of H2S donor sodium hydrogen sulfide (NaHS) on lymphatic vascularization and pro-angiogenic signaling pathways using both in vitro and in vivo approaches. In vitro dose-response experiments showed increased proliferation and tube formation by NaHS-treated human lymphatic endothelial cells (LECs) compared with control cells. Immunoblotting performed with LEC lysates prepared after time-course NaHS treatment demonstrated increased activation of ERK1/2, AKT and eNOS after 20 min of NaHS stimulation. Further, NaHS treatment induced nitric oxide production, reduced reactive oxygen species generation, and promoted cell cycle in LECs. Additional cell cycle analysis showed that NaHS treatment abrogates oxidized LDL-induced cell cycle arrest in LECs. The results of in vivo Matrigel plug assay revealed increased lymphatic vessel density in Matrigel plugs containing NaHS compared with control plugs, however, no significant differences in angiogenesis and immune cell infiltration were observed. Collectively, these findings suggest that H2S donor NaHS promotes lymphatic vessel formation both in vitro and in vivo and may be utilized to promote reparative lymphangiogenesis to alleviate lymphatic dysfunction-related disorders.

Direct endothelial ENaC activation mitigates vasculopathy induced by SARS-CoV2 spike protein

Introduction

Although both COVID-19 and non-COVID-19 ARDS can be accompanied by significantly increased levels of circulating cytokines, the former significantly differs from the latter by its higher vasculopathy, characterized by increased oxidative stress and coagulopathy in lung capillaries. This points towards the existence of SARS-CoV2-specific factors and mechanisms that can sensitize the endothelium towards becoming dysfunctional. Although the virus is rarely detected within endothelial cells or in the circulation, the S1 subunit of its spike protein, which contains the receptor binding domain (RBD) for human ACE2 (hACE2), can be detected in plasma from COVID-19 patients and its levels correlate with disease severity. It remains obscure how the SARS-CoV2 RBD exerts its deleterious actions in lung endothelium and whether there are mechanisms to mitigate this.

Methods

In this study, we use a combination of in vitro studies in RBD-treated human lung microvascular endothelial cells (HL-MVEC), including electrophysiology, barrier function, oxidative stress and human ACE2 (hACE2) surface protein expression measurements with in vivo studies in transgenic mice globally expressing human ACE2 and injected with RBD.

Results

We show that SARS-CoV2 RBD impairs endothelial ENaC activity, reduces surface hACE2 expression and increases reactive oxygen species (ROS) and tissue factor (TF) generation in monolayers of HL-MVEC, as such promoting barrier dysfunction and coagulopathy. The TNF-derived TIP peptide (a.k.a. solnatide, AP301) -which directly activates ENaC upon binding to its a subunit- can override RBD-induced impairment of ENaC function and hACE2 expression, mitigates ROS and TF generation and restores barrier function in HL-MVEC monolayers. In correlation with the increased mortality observed in COVID-19 patients co-infected with S. pneumoniae, compared to subjects solely infected with SARS-CoV2, we observe that prior intraperitoneal RBD treatment in transgenic mice globally expressing hACE2 significantly increases fibrin deposition and capillary leak upon intratracheal instillation of S. pneumoniae and that this is mitigated by TIP peptide treatment.

CD47 Activation by Thrombospondin-1 in Lymphatic Endothelial Cells Suppresses Lymphangiogenesis and Promotes Atherosclerosis

BACKGROUND

TSP1 (thrombospondin-1)-a well-known angiogenesis inhibitor-mediates differential effects via interacting with cell surface receptors including CD36 and CD47. However, the role of TSP1 in regulating lymphangiogenesis is not clear. Our previous study suggested the importance of cell-specific CD47 blockade in limiting atherosclerosis. Further, our experiments revealed CD47 as a dominant TSP1 receptor in lymphatic endothelial cells (LECs). As the lymphatic vasculature is functionally linked to atherosclerosis, we aimed to investigate the effects of LEC TSP1-CD47 signaling inhibition on lymphangiogenesis and atherosclerosis.

METHODS

Murine atherosclerotic and nonatherosclerotic arteries were utilized to investigate TSP1 expression using Western blotting and immunostaining. LEC-specific knockout mice were used to determine the in vivo role of LEC Cd47 in lymphangiogenesis and atherosclerosis. Various in vitro cell-based assays, in vivo Matrigel plug implantation, molecular biological techniques, and immunohistological approaches were used to evaluate the underlying signaling mechanisms.

RESULTS

Elevated TSP1 expression was observed in mouse atherosclerotic aortic tissue compared with nonatherosclerotic control tissue. TSP1 at pathological concentrations suppressed both in vitro and in vivo lymphangiogenesis. Mechanistically, TSP1 inhibited VEGF-C-induced AKT and eNOS activation in LEC and attenuated NO production. Further, Cd47 silencing in LEC prevented the effects of TSP1 on lymphangiogenic AKT-eNOS signaling and lymphangiogenesis. Atheroprone AAV8-PCSK9-injected LEC-specific Cd47 knockout mice (Cd47^ΔLEC) had reduced atherosclerosis in both aorta and aortic root compared with control mice (Cd47^ΔWT). However, no differences in metabolic parameters including body weight, plasma total cholesterol levels, and fasting blood glucose were observed. Additional immunostaining experiments performed on aortic root cross-sections indicated higher lymphatic vessel density in Cd47^ΔLEC in comparison to controls.

CONCLUSIONS

These findings demonstrate that TSP1 inhibits lymphangiogenesis via activation of CD47 in LEC, and loss of LEC Cd47 attenuates atherosclerotic lesion formation. Collectively, these results identify LEC CD47 as a potential therapeutic target in atherosclerosis.

Matricellular proteins in atherosclerosis development

The extracellular matrix (ECM) is an intricate network composed of various multi-domain macromolecules like collagen, proteoglycans, and fibronectin, etc., that form a structurally stable composite, contributing to the mechanical properties of tissue. However, matricellular proteins are non-structural, secretory extracellular matrix proteins, which modulate various cellular functions via interacting with cell surface receptors, proteases, hormones, and cell-matrix. They play essential roles in maintaining tissue homeostasis by regulating cell differentiation, proliferation, adhesion, migration, and several signal transduction pathways. Matricellular proteins display a broad functionality regulated by their multiple structural domains and their ability to interact with different extracellular substrates and/or cell surface receptors. The expression of these proteins is low in adults, however, gets upregulated following injuries, inflammation, and during tumor growth. The marked elevation in the expression of these proteins during atherosclerosis suggests a positive association between their expression and atherosclerotic lesion formation. The role of matricellular proteins in atherosclerosis development has remained an area of research interest in the last two decades and studies revealed these proteins as important players in governing vascular function, remodelling, and plaque formation. Despite extensive research, many aspects of the matrix protein biology in atherosclerosis are still unknown and future studies are required to investigate whether targeting pathways stimulated by these proteins represent viable therapeutic approaches for patients with atherosclerotic vascular diseases. This review summarizes the characteristics of distinct matricellular proteins, discusses the available literature on the involvement of matrix proteins in the pathogenesis of atherosclerosis and suggests new avenues for future research.

Piceatannol induces regulatory T cells and modulates the inflammatory response and adipogenesis

The beneficial effects of the polyphenolic compound piceatannol (PC) has been reported for metabolic diseases, antiproliferative, antioxidant, and anti-cancer properties. Despite its beneficial effects on inflammatory diseases, little is known about how PC regulates inflammatory responses and adipogenesis. Therefore, this study was designed to determine the effects of PC on the inflammatory response and adipogenesis. The effect of PC on splenocytes, 3T3-L1 adipocytes, and RAW264.7 macrophages was analyzed by flow cytometry, qRT-PCR, morphometry, and western blot analysis. PC induced apoptosis in activated T cells in a dose-dependent manner using stimulated splenocytes and reduced the activation of T cells, altered T cell frequency, and interestingly induced the frequency of regulatory T (Treg) cells as compared to controls. PC suppressed the expression of TNF-α, iNOS, IL-6R, and NF-κB activation in RAW264.7 macrophages after lipopolysaccharides (LPS)-induction as compared to the control. Interestingly, PC altered the cell morphology of 3T3-L1 adipocytes with a concomitant decrease in cell volume, lipid deposition, and TNF-α expression, but upregulation of leptin and IL-1β. Our findings suggested that PC induced apoptosis in activated T cells, decreased immune cell activation and inflammatory response, and hindered adipogenesis. This new set of data provides promising hope as a new therapeutic to treat both inflammatory disease and obesity.

Receptor-independent fluid-phase macropinocytosis promotes arterial foam cell formation and atherosclerosis

Accumulation of lipid-laden foam cells in the arterial wall plays a central role in atherosclerotic lesion development, plaque progression, and late-stage complications of atherosclerosis. However, there are still fundamental gaps in our knowledge of the underlying mechanisms leading to foam cell formation in atherosclerotic arteries. Here, we investigated the role of receptor-independent macropinocytosis in arterial lipid accumulation and pathogenesis of atherosclerosis. Genetic inhibition of fluid-phase macropinocytosis in myeloid cells (LysMCre+ Nhe1fl/fl) and repurposing of a Food and Drug Administration (FDA)-approved drug that inhibits macrophage macropinocytosis substantially decreased atherosclerotic lesion development in low-density lipoprotein (LDL) receptor-deficient and Apoe-/- mice. Stimulation of macropinocytosis using genetic (H-RASG12V) and physiologically relevant approaches promoted internalization of unmodified native (nLDL) and modified [e.g., acetylated (ac) and oxidized (ox) LDL] lipoproteins in both wild-type and scavenger receptor (SR) knockout (Cd36-/-/Sra-/-) macrophages. Pharmacological inhibition of macropinocytosis in hypercholesterolemic wild-type and Cd36-/-/Sra-/- mice identified an important role of macropinocytosis in LDL uptake by lesional macrophages and development of atherosclerosis. Furthermore, serial section high-resolution imaging, LDL immunolabeling, and three-dimensional (3D) reconstruction of subendothelial foam cells provide visual evidence of lipid macropinocytosis in both human and murine atherosclerotic arteries. Our findings complement the SR paradigm of atherosclerosis and identify a therapeutic strategy to counter the development of atherosclerosis and cardiovascular disease.

Reactive Oxygen Species in Regulating Lymphangiogenesis and Lymphatic Function

The lymphatic system is pivotal for immunosurveillance and the maintenance of tissue homeostasis. Lymphangiogenesis, the formation of new lymphatic vessels from pre-existing vessels, has both physiological and pathological roles. Recent advances in the molecular mechanisms regulating lymphangiogenesis have opened a new area of research on reparative lymphangiogenesis for the treatment of various pathological disorders comprising neurological disorders, cardiac repair, autoimmune disease, obesity, atherosclerosis, etc. Reactive oxygen species (ROS) produced by the various cell types serve as signaling molecules in several cellular mechanisms and regulate various aspects of growth-factor-mediated responses, including lymphangiogenesis. The ROS, including superoxide anion, hydrogen peroxide, and nitric oxide, play both beneficial and detrimental roles depending upon their levels and cellular microenvironment. Low ROS levels are essential for lymphangiogenesis. On the contrary, oxidative stress due to enhanced ROS generation and/or reduced levels of antioxidants suppresses lymphangiogenesis via promoting lymphatic endothelial cell apoptosis and death. In this review article, we provide an overview of types and sources of ROS, discuss the role of ROS in governing lymphangiogenesis and lymphatic function, and summarize the role of lymphatics in various diseases.

Loss of myeloid cell-specific SIRPα, but not CD47, attenuates inflammation and suppresses atherosclerosis

AIMS

Inhibitors of the anti-phagocytic CD47-SIRPα immune checkpoint are currently in clinical development for a variety of haematological and solid tumours. Application of immune checkpoint inhibitors to the cardiovascular field is limited by the lack of preclinical studies using genetic models of CD47 and SIRPα inhibition. In this study, we comprehensively analysed the effects of global and cell-specific SIRPα and CD47 deletion on atherosclerosis development.

METHODS AND RESULTS

Here, we show that both SIRPα and CD47 expression are increased in human atherosclerotic arteries and primarily co-localize to CD68+ areas in the plaque region. Hypercholesterolaemic mice homozygous for a Sirpa mutant lacking the signalling cytoplasmic region (Sirpamut/mut) and myeloid cell-specific Sirpa-knockout mice are protected from atherosclerosis. Further, global Cd47-/- mice are protected from atherosclerosis but myeloid cell-specific deletion of Cd47 increased atherosclerosis development. Using a combination of techniques, we show that loss of SIRPα signalling in macrophages stimulates efferocytosis, reduces cholesterol accumulation, promotes lipid efflux, and attenuates oxidized LDL-induced inflammation in vitro and induces M2 macrophage phenotype and inhibits necrotic core formation in the arterial wall in vivo. Conversely, loss of myeloid cell CD47 inhibited efferocytosis, impaired cholesterol efflux, augmented cellular inflammation, stimulated M1 polarization, and failed to decrease necrotic core area in atherosclerotic vessels. Finally, comprehensive blood cell analysis demonstrated lower haemoglobin and erythrocyte levels in Cd47-/- mice compared with wild-type and Sirpamut/mut mice.

CONCLUSION

Taken together, these findings identify SIRPα as a potential target in atherosclerosis and suggest the importance of cell-specific CD47 inhibition as a future therapeutic strategy.

MEK inhibition exerts temporal and myeloid cell-specific effects in the pathogenesis of neurofibromatosis type 1 arteriopathy

Mutations in the NF1 tumor suppressor gene are linked to arteriopathy. Nf1 heterozygosity (Nf1+/–) results in robust neointima formation, similar to humans, and myeloid-restricted Nf1+/– recapitulates this phenotype via MEK-ERK activation. Here we define the contribution of myeloid subpopulations to NF1 arteriopathy. Neutrophils from WT and Nf1+/– mice were functionally assessed in the presence of MEK and farnesylation inhibitors in vitro and neutrophil recruitment to lipopolysaccharide was assessed in WT and Nf1+/– mice. Littermate 12–15 week-old male wildtype and Nf1+/– mice were subjected to carotid artery ligation and provided either a neutrophil depleting antibody (1A8), liposomal clodronate to deplete monocytes/macrophages, or PD0325901 and neointima size was assessed 28 days after injury. Bone marrow transplant experiments assessed monocyte/macrophage mobilization during neointima formation. Nf1+/– neutrophils exhibit enhanced proliferation, migration, and adhesion via p21^Ras activation of MEK in vitro and in vivo. Neutrophil depletion suppresses circulating Ly6C^low monocytes and enhances neointima size, while monocyte/macrophage depletion and deletion of CCR2 in bone marrow cells abolish neointima formation in Nf1+/– mice. Taken together, these findings suggest that neurofibromin-MEK-ERK activation in circulating neutrophils and monocytes during arterial remodeling is nuanced and points to important cross-talk between these populations in the pathogenesis of NF1 arteriopathy.

P–391 Role of subcutaneous granulocyte colony-stimulating factor infusion in thin endometrium

Study question

To assess the role of subcutaneous granulocyte colony-stimulating factor (G-CSF) in thin endometrium cases.

Summary answer

G CSF has beneficial role to improve the endometrium thickness in thin endometrium.

What is known already

Endometrium is very important for embryo implantation and the endometrial thickness is the marker of receptivity of the endometrium.

Study design, size, duration

Study design - Retrospective analysis

Size - 88 infertile females with thin endometrium (< 7 mm) in the age group of 23 to 40 years Duration - one year.

Participants/materials, setting, methods

In the group 1 of 44 females, subcutaneous infusion of G CSF (300 mcg/ml) was added along with other supplements and if lining was not more than 7 mm in 72 hours, then second infusion was given. In the group 2 of 44 females, only estradiol valerate and sildenafil were given.The efficacy of G CSF was evaluated by assessing the endometrium thickness before embryo transfer, pregnancy rates and clinical pregnancy rates.

Main results and the role of chance

There was no difference between the two groups regarding demographic variables, egg reserve, sperm parameters, number of embryos transferred and embryo quality. . The pregnancy rate was 60% (24 out of 40 cases) in the group 1 that was significantly higher than in-group 2 that was 31% (9 out of 29 cases) with p value < 0.0001. The clinical pregnancy rate was also significantly higher in-group 1 (55%) as compared to group 2 (24%) with p value < 0.0001.

Limitations, reasons for caution

Further larger cohort studies are required to explore the subcutaneous role of G CSF in thin endometrium.

Wider implications of the findings: Granulocyte colony-stimulating factor has beneficial role to improve the endometrium thickness in thin endometrium. In most of previous studies, the intrauterine infusion of G CSF was given to improve the uterine lining. This is one of the few studies done that showed subcutaneous role of G CSF in thin endometrium.

Trial registration number

Not applicable

Visualizing Membrane Ruffle Formation using Scanning Electron Microscopy

Membrane ruffling is the formation of motile plasma membrane protrusions containing a meshwork of newly polymerized actin filaments. Membrane ruffles may form spontaneously or in response to growth factors, inflammatory cytokines, and phorbol esters. Some of the membrane protrusions may reorganize into circular membrane ruffles that fuse at their distal margins and form cups that close and separate into the cytoplasm as large, heterogeneous vacuoles called macropinosomes. During the process, ruffles trap extracellular fluid and solutes that internalize within macropinosomes. High-resolution scanning electron microscopy (SEM) is a commonly used imaging technique to visualize and quantify membrane ruffle formation, circular protrusions, and closed macropinocytic cups on the cell surface. The following protocol describes the cell culture conditions, stimulation of the membrane ruffle formation in vitro, and how to fix, dehydrate, and prepare cells for imaging using SEM. Quantification of membrane ruffling, data normalization, and stimulators and inhibitors of membrane ruffle formation are also described. This method can help answer key questions about the role of macropinocytosis in physiological and pathological processes, investigate new targets that regulate membrane ruffle formation, and identify yet uncharacterized physiological stimulators as well as novel pharmacological inhibitors of macropinocytosis.

Role of R-spondin 2 in arterial lymphangiogenesis and atherosclerosis

AIMS

Impaired lymphatic drainage of the arterial wall results in intimal lipid accumulation and atherosclerosis. However, the mechanisms regulating lymphangiogenesis in atherosclerotic arteries are not well understood. Our studies identified elevated levels of matrix protein R-spondin 2 (RSPO2) in atherosclerotic arteries. In this study, we investigated the role of RSPO2 in lymphangiogenesis, arterial cholesterol efflux into lesion-draining lymph nodes (LNs) and development of atherosclerosis.

METHODS AND RESULTS

The effect of RSPO2 on lymphangiogenesis was investigated using human lymphatic endothelial cells (LEC) in vitro and implanted Matrigel plugs in vivo. Cellular and molecular approaches, pharmacological agents, and siRNA silencing of RSPO2 receptor LGR4 were used to investigate RSPO2-mediated signalling in LEC. In vivo low-density lipoprotein (LDL) tracking and perivascular blockade of RSPO2-LGR4 signalling using LGR4-extracellular domain (ECD) pluronic gel in hypercholesterolemic mice were utilized to investigate the role of RSPO2 in arterial reverse cholesterol transport and atherosclerosis. Immunoblotting and imaging experiments demonstrated increased RSPO2 expression in human and mouse atherosclerotic arteries compared to non-atherosclerotic controls. RSPO2 treatment inhibited lymphangiogenesis both in vitro and in vivo. LGR4 silencing and inhibition of RSPO2-LGR4 signalling abrogated RSPO2-induced inhibition of lymphangiogenesis. Mechanistically, we found that RSPO2 suppresses PI3K-AKT-endothelial nitric oxide synthase (eNOS) signalling via LGR4 and inhibits activation of the canonical Wnt-β-catenin pathway. ApoE-/- mice treated with LGR4-ECD developed significantly less atherosclerosis compared with control treatment. Finally, increased arterial lymphatic vessel density and improved lymphatic drainage of fluorescently labelled LDL to deep cervical LNs were observed in LGR4-ECD-treated mice.

CONCLUSION

These findings demonstrate that RSPO2 inhibits lymphangiogenesis via LGR4 and downstream impairment of AKT-eNOS-nitric oxide signalling. These results may also inform new therapeutic strategies to promote lymphangiogenesis and improve cholesterol efflux from atherosclerotic arteries.

NADPH oxidase 1 mediates caerulein-induced pancreatic fibrosis in chronic pancreatitis

Inflammatory disorders of the pancreas are divided into acute (AP) and chronic (CP) forms. Both states of pancreatitis are a result of pro-inflammatory mediators, including reactive oxygen species (ROS). One of the sources of ROS is NADPH oxidase (Nox). The rodent genome encodes Nox1-4, Duox1 and Duox2. Our purpose was to assess the extent to which Nox enzymes contribute to the pathogenesis of both AP and CP using Nox-deficient mice. Using RT-PCR, Nox1 was found in both isolated mouse pancreatic acini and pancreatic stellate cells (PaSCs). Subsequently, mice with genetically deleted Nox1 were further studied and showed that the histo-morphologic characteristics of caerulein-induced CP, but not caerulein-induced AP, was ameliorated in Nox1 KO mice. We also found that the lack of Nox1 impaired caerulein-induced ROS generation in PaSCs. Using Western blotting, we found that AKT mediates the fibrotic effect of Nox1 in a mouse model of CP. We also found a decrease in phospho-ERK and p38MAPK levels in Nox1 KO mice with CP, but not with AP. Both CP-induced TGF-β up-regulation and NF-ĸB activation were impaired in pancreas from Nox1 KO mice. Western blotting indicated increases in proteins involved in fibrosis and acinar-to-ductal metaplasia in WT mice with CP. No change in those proteins were observed in Nox1 KO mice. The lack of Nox1 lowered mRNA levels of CP-induced matrix metalloproteinase MMP-9 and E-cadherin repressor Twist in PaSCs. CONCLUSION: Nox1-derived ROS in PaSCs mediate the fibrotic process of CP by activating the downstream redox-sensitive signaling pathways AKT and NF-ĸB, up-regulating MMP-9 and Twist, and producing α-smooth muscle actin and collagen I and III.

Copper Transporter ATP7A (Copper-Transporting P-Type ATPase/Menkes ATPase) Limits Vascular Inflammation and Aortic Aneurysm Development: Role of MicroRNA-125b

OBJECTIVE

Copper (Cu) is essential micronutrient, and its dysregulation is implicated in aortic aneurysm (AA) development. The Cu exporter ATP7A (copper-transporting P-type ATPase/Menkes ATPase) delivers Cu via the Cu chaperone Atox1 (antioxidant 1) to secretory Cu enzymes, such as lysyl oxidase, and excludes excess Cu. Lysyl oxidase is shown to protect against AA formation. However, the role and mechanism of ATP7A in AA pathogenesis remain unknown. Approach and Results: Here, we show that Cu chelator markedly inhibited Ang II (angiotensin II)-induced abdominal AA (AAA) in which ATP7A expression was markedly downregulated. Transgenic ATP7A overexpression prevented Ang II-induced AAA formation. Conversely, Cu transport dysfunctional ATP7A^mut/+/ApoE^-/- mice exhibited robust AAA formation and dissection, excess aortic Cu accumulation as assessed by X-ray fluorescence microscopy, and reduced lysyl oxidase activity. In contrast, AAA formation was not observed in Atox1^-/-/ApoE^-/- mice, suggesting that decreased lysyl oxidase activity, which depends on both ATP7A and Atox1, was not sufficient to develop AAA. Bone marrow transplantation suggested importance of ATP7A in vascular cells, not bone marrow cells, in AAA development. MicroRNA (miR) array identified miR-125b as a highly upregulated miR in AAA from ATP7A^mut/+/ApoE^-/- mice. Furthermore, miR-125b target genes (histone methyltransferase Suv39h1 and the NF-κB negative regulator TNFAIP3 [tumor necrosis factor alpha induced protein 3]) were downregulated, which resulted in increased proinflammatory cytokine expression, aortic macrophage recruitment, MMP (matrix metalloproteinase)-2/9 activity, elastin fragmentation, and vascular smooth muscle cell loss in ATP7A^mut/+/ApoE^-/- mice and reversed by locked nucleic acid-anti-miR-125b infusion.

CONCLUSIONS

ATP7A downregulation/dysfunction promotes AAA formation via upregulating miR-125b, which augments proinflammatory signaling in a Cu-dependent manner. Thus, ATP7A is a potential therapeutic target for inflammatory vascular disease.

Arterial Lymphatics in Atherosclerosis: Old Questions, New Insights, and Remaining Challenges

The lymphatic network is well known for its role in the maintenance of tissue fluid homeostasis, absorption of dietary lipids, trafficking of immune cells, and adaptive immunity. Aberrant lymphatic function has been linked to lymphedema and immune disorders for a long time. Discovery of lymphatic cell markers, novel insights into developmental and postnatal lymphangiogenesis, development of genetic mouse models, and the introduction of new imaging techniques have improved our understanding of lymphatic function in both health and disease, especially in the last decade. Previous studies linked the lymphatic vasculature to atherosclerosis through regulation of immune responses, reverse cholesterol transport, and inflammation. Despite extensive research, many aspects of the lymphatic circulation in atherosclerosis are still unknown and future studies are required to confirm that arterial lymphangiogenesis truly represents a therapeutic target in patients with cardiovascular disease. In this review article, we provide an overview of factors and mechanisms that regulate lymphangiogenesis, summarize recent findings on the role of lymphatics in macrophage reverse cholesterol transport, immune cell trafficking and pathogenesis of atherosclerosis, and present an overview of pharmacological and genetic strategies to modulate lymphatic vessel density in cardiovascular tissue.

PKCδ stimulates macropinocytosis via activation of SSH1-cofilin pathway

Macropinocytosis is an actin-dependent endocytic mechanism mediating internalization of extracellular fluid and associated solutes into cells. The present study was designed to identify the specific protein kinase C (PKC) isoform(s) and downstream effectors regulating actin dynamics during macropinocytosis. We utilized various cellular and molecular biology techniques, pharmacological inhibitors and genetically modified mice to study the signaling mechanisms mediating macropinocytosis in macrophages. The qRT-PCR experiments identified PKCδ as the predominant PKC isoform in macrophages. Scanning electron microscopy and flow cytometry analysis of FITC-dextran internalization demonstrated the functional role of PKCδ in phorbol ester- and hepatocyte growth factor (HGF)-induced macropinocytosis. Western blot analysis demonstrated that phorbol ester and HGF stimulate activation of slingshot phosphatase homolog 1 (SSH1) and induce cofilin Ser-3 dephosphorylation via PKCδ in macrophages. Silencing of SSH1 inhibited cofilin dephosphorylation and macropinocytosis stimulation. Interestingly, we also found that incubation of macrophages with BMS-5, a potent inhibitor of LIM kinase, does not stimulate macropinocytosis. In conclusion, the findings of the present study demonstrate a previously unidentified mechanism by which PKCδ via activation of SSH1 and cofilin dephosphorylation stimulates membrane ruffle formation and macropinocytosis. The results of the present study may contribute to a better understanding of the regulatory mechanisms during macrophage macropinocytosis.

Identification of novel macropinocytosis inhibitors using a rational screen of Food and Drug Administration-approved drugs

BACKGROUND AND PURPOSE

Macropinocytosis is involved in many pathologies, including cardiovascular disorders, cancer, allergic diseases, viral and bacterial infections. Unfortunately, the currently available pharmacological inhibitors of macropinocytosis interrupt other endocytic processes and have non-specific endocytosis-independent effects. Here we have sought to identify new, clinically relevant inhibitors of macropinocytosis, using an FDA-approved drug library.

EXPERIMENTAL APPROACH

In the present study, 640 FDA-approved compounds were tested for their ability to inhibit macropinocytosis. A series of secondary assays were performed to confirm inhibitory activity, determine IC50 values and investigate cell toxicity. The ability of identified hits to inhibit phagocytosis and clathrin-mediated and caveolin-mediated endocytosis was also investigated. Scanning electron microscopy and molecular biology techniques were utilized to examine the mechanisms by which selected compounds inhibit macropinocytosis.

KEY RESULTS

The primary screen identified 14 compounds that at ~10 μM concentration inhibit >95% of macropinocytotic solute internalization. Three compounds - imipramine, phenoxybenzamine and vinblastine - potently inhibited (IC50  ≤ 131 nM) macropinocytosis without exerting cytotoxic effects or inhibiting other endocytic pathways. Scanning electron microscopy imaging indicated that imipramine inhibits membrane ruffle formation, a critical early step leading to initiation of macropinocytosis. Finally, imipramine has been shown to inhibit macropinocytosis in several cell types, including cancer cells, dendritic cells and macrophages.

CONCLUSIONS AND IMPLICATIONS

Our results identify imipramine as a new pharmacological tool to study macropinocytosis in cellular and biological systems. This study also suggests that imipramine could be a good candidate for repurposing as a therapeutic agent in pathological processes involving macropinocytosis.

Abstract 230: Matrix Regulation of Lymphangiogenesis in Atherosclerosis

Background: Atherosclerosis is a consequence of an imbalance of cellular uptake of lipoproteins versus removal of cholesterol from the arterial wall. The lymphatic vasculature represents the primary route of cholesterol removal from atherosclerotic vessels. Previous studies have linked matrix protein thrombospondin-1 (TSP1), a well-known inhibitor of angiogenesis, with human atherosclerotic disease; however the mechanisms by which TSP1 contributes to atherosclerosis and its effect on arterial lymphangiogenesis remain unknown.

Methods: The effect of TSP1 on human lymphatic endothelial cell (LEC) proliferation, migration and tube formation was investigated in vitro . TSP1 protein expression was analyzed in human and murine (ApoE -/- , 12 weeks Western diet) atherosclerotic aortic tissue and lesion free segments using Western blotting. The role of TSP1 and its cognate receptor CD47 in the pathogenesis of atherosclerosis was investigated using knockout animals.

Results: TSP1 expression was significantly increased in both human and ApoE -/- atherosclerotic arteries compared to plaque free segments in human and wild type aortic tissue. TSP1 at physiologically relevant concentrations (11-22 nM, 24 hrs) inhibited LEC proliferation, migration, and tube formation. RT-PCR data demonstrated that CD47 is the predominant TSP1 receptor expressed in LEC (> 50-fold over CD36 mRNA levels). Finally, genome-wide deficiency in TSP1 and CD47 receptor attenuated atherosclerotic lesion formation in the aorta and brachiocephalic artery by ~50% compared to wild type controls. Importantly, there was no difference in plasma cholesterol levels, body weight, fat and lean mass, fasting plasma glucose, and blood pressure between the experimental groups.

Conclusions: The present study suggests that matrix protein TSP1 via CD47 receptor contributes to the pathogenesis of atherosclerosis. Inhibition of arterial lymphangiogenesis by TSP1-CD47 signaling may contribute to arterial lipid accumulation and atherosclerosis.

Abstract 100: High-throughput Screening of FDA-approved Drugs Identifies Novel Inhibitors of Macropinocytosis

Aims: Macropinocytosis has been implicated in atherosclerosis, cancer, allergic disorders, and other pathologies. Unfortunately, most currently available pharmacological inhibitors of macropinocytosis interrupt other endocytic processes and have non-specific endocytosis-independent effects. The goal of the present study was to perform a high-throughput screen (HTS) of FDA-approved drugs to identify new, clinically relevant inhibitors of macropinocytosis.

Methods: In the present study, 640 FDA-approved compounds were tested for their ability to inhibit macropinocytosis. A series of secondary assays were performed to confirm inhibitory activity, determine IC 50 values, and investigate cell toxicity. The ability of identified hits to inhibit phagocytosis, clathrin- and caveolin-mediated endocytosis was also investigated. Scanning electron microscopy and molecular biology techniques were utilized to investigate the mechanisms by which selected compounds inhibit macropinocytosis.

Results: The HTS campaign identified 14 compounds that at ~10 μM concentration inhibit >95% of macropinocytotic solute internalization. Our results demonstrated that three lead compounds, namely imipramine, phenoxybenzamine, and vinblastine, potently inhibit (IC 50 ≤ 130 nM) macropinocytosis without exerting cytotoxic effects or inhibiting other endocytic pathways. Mechanistically, we found that imipramine inhibits translocation of ADP-ribosylation factor 6 to the plasma membrane and prevents membrane ruffle formation, a critical early step leading to macropinocytosis. Imipramine inhibited macropinocytosis in multiple cell types, including cancer cells, dendritic cells, and macrophages. Finally, incubation of macrophages with imipramine inhibited nLDL macropinocytosis and foam cell formation in vitro .

Innovation and Conclusion: The identified macropinocytosis inhibitors may prove useful as new pharmacological tools to more fully discern the role of macropinocytosis in pathological processes and as therapeutic agents in various disorders involving macropinocytosis.

PKCδ-Mediated Nox2 Activation Promotes Fluid-Phase Pinocytosis of Antigens by Immature Dendritic Cells

Aims

Macropinocytosis is a major endocytic pathway by which dendritic cells (DCs) internalize antigens in the periphery. Despite the importance of DCs in the initiation and control of adaptive immune responses, the signaling mechanisms mediating DC macropinocytosis of antigens remain largely unknown. The goal of the present study was to investigate whether protein kinase C (PKC) is involved in stimulation of DC macropinocytosis and, if so, to identify the specific PKC isoform(s) and downstream signaling mechanisms involved.

Methods

Various cellular, molecular and immunological techniques, pharmacological approaches and genetic knockout mice were utilized to investigate the signaling mechanisms mediating DC macropinocytosis.

Results

Confocal laser scanning microscopy confirmed that DCs internalize fluorescent antigens (ovalbumin) using macropinocytosis. Pharmacological blockade of classical and novel PKC isoforms using calphostin C abolished both phorbol ester- and hepatocyte growth factor-induced antigen macropinocytosis in DCs. The qRT-PCR experiments identified PKCδ as the dominant PKC isoform in DCs. Genetic studies demonstrated the functional role of PKCδ in DC macropinocytosis of antigens, their subsequent maturation, and secretion of various T-cell stimulatory cytokines, including IL-1α, TNF-α and IFN-β. Additional mechanistic studies identified NADPH oxidase 2 (Nox2) and intracellular superoxide anion as important players in DC macropinocytosis of antigens downstream of PKCδ activation.

Conclusion

The findings of the present study demonstrate a novel mechanism by which PKCδ activation via stimulation of Nox2 activity and downstream redox signaling promotes DC macropinocytosis of antigens. PKCδ/Nox2-mediated antigen macropinocytosis stimulates maturation of DCs and secretion of T-cell stimulatory cytokines. These findings may contribute to a better understanding of the regulatory mechanisms in DC macropinocytosis and downstream regulation of T-cell-mediated responses.

Nox2-Mediated PI3K and Cofilin Activation Confers Alternate Redox Control of Macrophage Pinocytosis

AIMS

Internalization of extracellular fluid and its solute by macropinocytosis requires dynamic reorganization of actin cytoskeleton, membrane ruffling, and formation of large endocytic vacuolar compartments, called macropinosomes, inside the cell. Although instigators of macropinocytosis, such as growth factors and phorbol esters, stimulate NADPH oxidase (Nox) activation and signal transduction mediators upstream of Nox assembly, including Rac1 and protein kinase C (PKC), are involved in macropinocytosis, the role of Nox enzymes in macropinocytosis has never been investigated. This study was designed to examine the role of Nox2 and the potential downstream redox signaling involved in macropinocytosis.

RESULTS

Phorbol myristate acetate activation of human and murine macrophages stimulated membrane ruffling, macropinosome formation, and subsequent uptake of macromolecules by macropinocytosis. Mechanistically, we found that pharmacological blockade of PKC, transcriptional knockdown of Nox2, and scavenging of intracellular superoxide anion abolished phorbol ester-induced macropinocytosis. We observed that Nox2-derived reactive oxygen species via inhibition of phosphatase and tensin homolog and activation of the phosphoinositide-3-kinase (PI3K)/Akt pathway lead to activation of actin-binding protein cofilin, membrane ruffling, and macropinocytosis. Similarly, activation of macropinocytosis by macrophage colony-stimulating factor involves Nox2-mediated cofilin activation. Furthermore, peritoneal chimera experiments indicate that macropinocytotic uptake of lipids in hypercholesterolemic ApoE^-/- mice was attenuated in Nox2^y/- macrophages compared with wild-type controls. Innovation and Conclusion: In summary, these findings demonstrate a novel Nox2-mediated mechanism of solute uptake via macropinocytosis, with broad implications for both general cellular physiology and pathological processes. The redox mechanism described here may also identify new targets in atherosclerosis and other disease conditions involving macropinocytosis. Antioxid. Redox Signal. 26, 902-916.

CD47 and Nox1 Mediate Dynamic Fluid-Phase Macropinocytosis of Native LDL

AIMS

Macropinocytosis has been implicated in cardiovascular and other disorders, yet physiological factors that initiate fluid-phase internalization and the signaling mechanisms involved remain poorly identified. The present study was designed to examine whether matrix protein thrombospondin-1 (TSP1) stimulates macrophage macropinocytosis and, if so, to investigate the potential signaling mechanism involved.

RESULTS

TSP1 treatment of human and murine macrophages stimulated membrane ruffle formation and pericellular solute internalization by macropinocytosis. Blockade of TSP1 cognate receptor CD47 and NADPH oxidase 1 (Nox1) signaling, inhibition of phosphoinositide 3-kinase, and transcriptional knockdown of myotubularin-related protein 6 abolished TSP1-induced macropinocytosis. Our results demonstrate that Nox1 signaling leads to dephosphorylation of actin-binding protein cofilin at Ser-3, actin remodeling, and macropinocytotic uptake of unmodified native low-density lipoprotein (nLDL), leading to foam cell formation. Finally, peritoneal chimera studies suggest the role of CD47 in macrophage lipid macropinocytosis in hypercholesterolemic ApoE^-/- mice in vivo.

INNOVATION

Activation of a previously unidentified TSP1-CD47 signaling pathway in macrophages stimulates direct receptor-independent internalization of nLDL, leading to significant lipid accumulation and foam cell formation. These findings reveal a new paradigm in which delimited Nox1-mediated redox signaling, independent of classical lipid oxidation, contributes to early propagation of vascular inflammatory disease.

CONCLUSIONS

The findings of the present study demonstrate a new mechanism of solute uptake with implications for a wide array of cell types, including macrophages, dendritic cells, and cancer cells, and multiple pathological conditions in which matrix proteins are upregulated. Antioxid. Redox Signal. 26, 886-901.

Abstract 3: Cellular Contributions of the Circadian Clock in Atherogenesis

Atherosclerosis is a leading cause of death despite the improvements in lipid and blood pressure control. The circadian clock, a molecular network of genes and proteins that controls 24-hour timing, has emerged to have a surprising role in the control of metabolic and vascular function. Herein we examined the impact of circadian rhythm dysfunction in atherogenesis by implementation of vascular transplant and PCSK9 based approaches to induce accelerated lesion development in mice. We find that atherogenesis is exacerbated in Bmal1-KO aortic grafts immersed in the hypercholesterolemic milieu of ApoE -/- mice. To assess if atherosclerosis was ‘circadian rhythm dependent’ we subjected wild-type mice to a shortened light cycle (4L/4D) and induced atherosclerosis by intravenous injection of a human PCSK-9 adeno associated virus. Atherosclerosis in the jet-lagged PCSK-9 mice was robustly increased relative to the atherosclerosis observed in WT mice on a normal light cycle (12L/12D), providing further evidence that circadian rhythm and the circadian clock contribute to atherosclerosis. However, atherosclerosis is a complex disease that is the net result of interplay between intrinsic (vascular cells) and extrinsic mechanisms (metabolism, blood pressure, and hormones) and the importance of clock function in individual cell types is poorly understood. We found that deletion or silencing of key circadian transcription factors resulted in an enhanced inflammatory and pro-oxidant phenotype with diminished NO production and greater lipid uptake in both macrophages and endothelial cells. Loss of circadian function in smooth muscle cells similarly resulted in enhanced production of reactive oxygen species and greater cell proliferation. Surprising, the silencing of Bmal2 in endothelial cells resulted in greater lipid uptake in oxLDL treated HAEC as well as increased expression of markers of autophagy, suggesting that Bmal2 may orchestrate numerous output functions in different cell types. In conclusion, we find that the circadian clock and circadian rhythm have a profound impact on atherosclerosis, to influence vascular cell inflammatory and lipid uptake responses, and identify an unexpectedly prominent role for the side-partner of Bmal1, Bmal2.

Genetic polymorphism in CD14 gene, a co-receptor of TLR4 associated with non-alcoholic fatty liver disease

AIM

To evaluate the pathogenic role of toll-like receptor (TLR) gene polymorphisms in patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

Two hundred and fifty subjects (NAFLD = 200, healthy volunteers = 50) underwent polymerase chain reaction and restriction fragment length polymorphism to assess one polymorphism in the toll-like receptor 2 (TLR2) gene (A753G), two polymorphisms in the TLR4 gene (TLR4 Asp299Gly and Thr399Ile allele), and two polymorphisms in the cluster of differentiation 14 (CD14) (C-159T and C-550T) gene, a co-receptor of TLR4. Association of TLR gene polymorphisms with NAFLD and its severity was evaluated by genetic models of association.

RESULTS

On both multiplicative and recessive models of gene polymorphism association, there was significant association of CD14 C (-159) T polymorphism with NAFLD; patients with TT genotype had a 2.6 fold increased risk of developing NAFLD in comparison to CC genotype. There was no association of TLR2 Arg753Gln, TLR4 Asp299Gly, Thr399Ile, and CD14 C (-550) T polymorphisms with NAFLD. None of the TLR gene polymorphisms had an association with histological severity of NAFLD.

CONCLUSION

Patients with CD14 C (-159) T gene polymorphism, a co-receptor of TLR4, have an increased risk of NAFLD development.

Abstract 646: Redox Control of Macropinocytosis; An Unexplored Target in Atherosclerosis

Aims: Early studies established the paradigm that oxidation of low density lipoprotein (LDL) is necessary for scavenger receptor-mediated LDL uptake and lipid accumulation in macrophages. In addition to this “classical” mode of lipid internalization, scavenger receptor-independent uptake of native, non-oxidized LDL (nLDL) via macropinocytosis has been demonstrated to contribute to lipid uptake by macrophages. Despite this previous information the precise signaling mechanisms regulating macropinocytosis of nLDL and the relative contribution of lipid macropinocytosis to atherosclerosis remain unknown. This study was designed to examine the role of phagocyte NADPH oxidase (a.k.a. Nox2) in macropinocytosis and to investigate macropinocytotic uptake of lipids in hypercholesterolemic ApoE -/- mice in vivo .

Results: Phorbol myristate acetate (4β-PMA) activation of human and murine macrophages stimulated membrane ruffling, macropinosome formation, and subsequent uptake of nLDL by macropinocytosis. FACS data indicated that 4β-PMA stimulates lipid accumulation following nLDL treatment in macrophages lacking scavenger receptor CD36. Mechanistically, we found that pharmacological blockade of protein kinase C (PKC), inhibition of flavoenzymes by diphenyleneiodonium, and scavenging intracellular superoxide anion abolished phorbol ester-induced macropinocytosis. Transcriptional knockdown of Nox2 using siRNA inhibited 4β-PMA-induced macropinocytosis in THP-1 macrophages. Delving further into the mechanism, we found that Nox2 via redox inactivation of PTEN and activation of the PI3K/Akt pathway dephosphorylates the actin-binding protein cofilin, stimulates membrane ruffling, and induces macropinocytosis. Finally, peritoneal chimera experiments indicate that macropinocytotic uptake of lipids in hypercholesterolemic ApoE -/- mice was attenuated in Nox2 y/- macrophages compared to wild type controls.

Innovation and Conclusion: These findings suggest a previously undescribed redox-sensitive signaling pathway leading to internalization of nLDL by macropinocytosis. The signaling mechanism described herein may identify new targets in atherosclerosis and other disease conditions involving macropinocytosis.

Small intestinal bacterial overgrowth and toll-like receptor signaling in patients with non-alcoholic fatty liver disease

BACKGROUND AND AIM

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is multifactorial. There is sparse literature on the role of small intestinal bacterial overgrowth (SIBO) and toll-like receptor (TLR) signaling in NAFLD. The present study evaluated the relationship of SIBO with expression of TLR signaling genes in patients with NAFLD.

METHODS

A total of 142 subjects composed of NAFLD (n = 60, mean age 38.7 ± 10.4 years), chronic viral hepatitis (CVH) (n = 32, mean age 39.5 ± 10.6 years), and healthy volunteers (n = 50, mean age 36.56 ± 4.2 years) were enrolled in the study. Duodenal fluid was taken endoscopically in 32 prospective patients with NAFLD for evaluation of SIBO. Hepatic mRNA expression of TLR4, CD14, TLR2, NF-κβ, and MD2 and protein expression of TLR4 and TLR2 were studied in 64 patients (NAFLD = 32, CVH = 32) by RT-PCR and immunohistochemistry, respectively. Serum levels of TNF-α, adiponectin, insulin, and endotoxins were also evaluated.

RESULTS

Small intestinal bacterial overgrowth was present in 12 (37.5%) out of 32 patients with NAFLD with Escherichia coli as the predominant bacterium. In comparison with those without SIBO, patients with SIBO had significantly higher endotoxin levels and higher CD14 mRNA, nuclear factor kappa beta mRNA, and TLR4 protein expression. Patients with NASH had significantly higher endotoxin levels and higher intensity of TLR4 protein expression in comparison with patients without NASH. Serum levels of TNF-α, endotoxins, and insulin were significantly higher and of adiponectin lower in NAFLD in comparison with CVH and healthy volunteers.

CONCLUSIONS

Our study provides the first direct evidence of role of SIBO and endotoxemia and its relation with TLR signaling genes and liver histology in patients with NAFLD.

Gastric lavage for prevention of feeding problems in neonates with meconium-stained amniotic fluid: a randomised controlled trial

BACKGROUND

The role of gastric lavage in preventing retching, vomiting and secondary meconium aspiration syndrome in neonates with meconium-stained amniotic fluid is uncertain, and no there are no definitive guidelines.

OBJECTIVE

To evaluate the effect of gastric lavage in preventing retching, vomiting and secondary meconium aspiration syndrome in neonates with meconium-stained amniotic fluid.

METHODS

This was an open-label, parallel, randomized controlled trial conducted in the labour room, postnatal and neonatal wards of a tertiary-care teaching hospital. Vigorous neonates of ≧34 weeks gestation with meconium-stained amniotic fluid were randomised into two groups using block randomisation. Infants requiring oxygen, in respiratory distress or with major congenital malformations were excluded. Infants in the study group received elective gastric lavage in the labour room after initial stabilisation. No gastric lavage was done in the control group. The newborns were assessed for retching, vomiting and secondary meconium aspiration syndrome in the first 48 hrs of life or until discharge from the hospital, whichever was later.

RESULTS

A total of 267 newborns were randomly assigned to the gastric lavage group and 269 to the no gastric lavage group. There were no statistical differences in overall feeding between the two groups (6·74% vs 10·78%). Feeding of two newborns in the no-lavage group had to be omitted for the initial few hours because of vomiting; this did not happen in any newborn in the lavage group. No newborn in either group developed secondary meconium aspiration syndrome.

CONCLUSION

Gastric lavage in newborns with meconium-stained amniotic fluid does not prevent or reduce the occurrence of feeding problems or secondary meconium aspiration syndrome.

Levels of hepatitis B virus replicative intermediate in serum samples of chronic hepatitis B patients

Hepatitis B virus (HBV) cccDNA levels is an absolute marker of HBV replication in the liver of HBV infected patients. This study aimed to quantify the HBV cccDNA levels in sera and liver tissue samples of treatment naïve patients with chronic hepatitis B. Eighty one chronic hepatitis B (CHB) treatment naïve patients were enrolled from January 2009 to June 2011. Total HBV DNA and HBV cccDNA levels were quantified using sensitive real time PCR assay. The mean age of recruited patients was 34 ± 11.5 years. Fifty four (66.7%) patients were HBeAg negative. Liver tissue samples were available from 2 HBeAg positive and 21 HBeAg negative CHB patients. The amount of total intrahepatic HBV DNA ranged from 0.09 to 1508.92 copies/cell. The median intrahepatic HBV cccDNA was 0.31 and 0.20 copies/cell in HBeAg positive and HBeAg negative cases, respectively. Serum HBV cccDNA was detectable in 85.2 % HBeAg positive and 48.1% HBeAg negative CHB patients. Median serum HBV cccDNA was 46,000 and 26,350 copies/mL in HBeAg positive and HBeAg negative subjects, respectively. There was a significant positive correlation between the levels of intrahepatic total HBV DNA and intrahepatic HBV cccDNA (r = 0.533, p = 0.009). A positive correlation was also seen between serum HBV cccDNA levels and serum HBV DNA levels (r = 0.871, p < 0.001). It was concluded that serum HBV cccDNA could be detectable in higher proportion of HBeAg positive patients compared to HBeAg negative patients. Moreover, the median level of serum HBV cccDNA was significantly higher in HBeAg positive patients in contrast to HBeAg negative subjects.

Hepatitis B virus reverse transcriptase mutations in treatment Naïve chronic hepatitis B patients

Mutations in the reverse transcriptase (RT) region of the hepatitis B virus (HBV) genome lead to decreased susceptibility to nucleos(t)ide analogs approved for treatment of HBV infection. The aim of this study was to detect and analyze pre-existing HBV RT mutations in treatment naïve patients with chronic hepatitis B. Seventy one chronic HBV treatment naïve patients were enrolled from January 2009 to June 2011. HBV RT sequence analysis was done by using direct bidirectional sequencing of semi-nested PCR products. HBV genotypes were determined by multiplex PCR. Genotype D was found in 64 patients (90.1%) followed by genotype C and A which were present in 5 (7.0%) and 2 (2.8%) patients respectively. The results of the RT sequence analysis showed mutations in 34 (47.9%) patients. The rtH248N mutation was the most common mutation, accounting for 47.1% patients. Other common mutations included rtD263E/S, rtM129L, rtF122L/V/I, rtS135Y/H, rtQ149K, rtL91I, rtH126R, rtC256S/G, rtY257W, rtS259T and rtE271D, which were present in 26.5% (9/34), 29.4% (10/34), 20.6% (7/34), 20.6% (7/34), 20.6% (7/34), 17.6% (6/34), 14.7% (5/34), 14.7% (5/34), 11.8% (4/34), 11.8% (4/34) and 11.8% (4/34) patients respectively. The known primary drug resistance mutations were found in 3 (8.8%) patients. The present study shows the presence of RT amino acid substitutions in treatment-naïve patients with chronic hepatitis B, which may decrease susceptibility to available oral antiviral drugs. On the basis of the finding of this study, genotypic testing is recommended before the start of therapy in naïve patients, so that suitable antiviral drugs can be prescribed.

Serum levels of angiogenic and anti-angiogenic factors: their prognostic relevance in locally advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prototype tumor wherein angiogenesis plays a vital role in its progression. The role of VEGF, a major angiogenic factor in HCC is known; however, the role of anti-angiogenic factors simultaneously with the angiogenic factors has not been studied before. Hence, in this study, the serum levels of major angiogenic [Vascular Endothelial Growth Factor (VEGF), angiopoietin-2 (Ang-2)] and anti-angiogenic (endostatin, angiostatin) factors were analyzed and correlated with clinico-radiological features and with outcome. A total of 150 patients (50 HCC, 50 cirrhosis and 50 chronic hepatitis) and 50 healthy controls were enrolled in this study. Serum levels of VEGF, Ang-2, endostatin, and angiostatin were estimated by enzyme-linked immunosorbent assay. HCC shows significantly elevated serum levels of angiogenic factors VEGF and Ang-2 and of anti-angiogenic factors endostatin and angiostatin. ROC curve analysis for serum VEGF yielded an optimal cut-off value of 225.14 pg/ml, with a sensitivity of 78 % and specificity of 84.7 % for a diagnosis of HCC and its distinction from other group. Using this value, the univariate and multivariate analysis revealed significantly poor outcome in patients with higher levels of serum VEGF (p = 0.009). Combinatorial analysis revealed that patients with higher levels of both angiogenic and anti-angiogenic factors showed poor outcome. Serum VEGF correlates with poor survival of HCC patients and, therefore, serves as a non-invasive biomarker of poor prognosis. Moreover, elevated levels of anti-angiogenic factors occur endogenously in HCC patients.

Duodenal tuberculosis presenting as gatric outlet obstruction

Tuberculosis of stomach and duodenum is very uncommon even in patients with pulmonary and intestinal tuberculosis. Its preoperative diagnosis still remains a challenging problem for surgeons. Herein, we report the case of isolated duodenal tuberculosis in a 42 year old male presenting with gastric outlet obstruction symptoms. Oesophago-gastro-duodenoscopy (UGIE) revealed fold thickening at D3 segment but endoscopic biopsy was inconclusive, CECT abdomen showed ill-defined soft tissue thickening involving the 3(rd) part of duodenum with mesenteric fat stranding. Exploratory laparotomy was done which showed growth at 3rd part of the duodenum and peritoneal seedlings, tissue biopsy was taken and gastro-jejunostomy with jejuno-jejunostomy was done. Histopathological examination was consistent with the features of gastrointestinal tuberculosis. Patient was started on anti-tubercular therapy and was cured of the disease.

Quantification of hypoxia-inducible factor-1α, vascular endothelial growth factor, and angiopoietin-2 expression in hepatocellular carcinoma using a real-time quantitative reverse transcription polymerase chain reaction

223

Background: Hepatocellular carcinoma (HCC) is characteristically a hypervascular tumor and its progression is closely related to angiogenesis. Hypoxia inducible factor-1α (HIF-1 α), vascular endothelial growth factor (VEGF), and angiopioetin-2 (Ang-2) are key angiogenic factors in HCC. In this study, expression of HIF-1α, VEGF, and Ang-2 were analyzed and correlated with clinicopathologic features of HCC.

Methods: Expression of HIF-1α, VEGF, and Ang-2 were analyzed by real-time quantitative reverse transcription polymerase chain reaction in 67 HCC patients (23HBV, 22HCV, 22NBNC) with mean age 59.09 ± 11.13 years (60 M: 7 F), 9 cirrhosis patients (2HBV, 2HCV, 5ALD) with mean age 48.33 ± 11.31 years (8 M:1 F), and 14 chronic hepatitis patients (7HBV, 7HCV) with mean age 48.33 ± 7.17 years (10 M: 4 F), respectively. HCC was diagnosed on the basis of EASL (European Association for the Study of the Liver) criteria.

Results: Expression of HIF-1α and VEGF were found to be significantly higher in patients with HCC compared with cirrhosis and chronic hepatitis. Although Ang-2 expression was higher in HCC compared to cirrhosis and chronic hepatitis but the difference was not statistically significant. The difference in the expression of HIF-1α, VEGF, and Ang-2 in cirrhosis and chronic hepatitis were not significant. Tumor size was positively correlated with HIF-1 α(p = 0.268, p = 0.030)and VEGF (p = 0.546, p = 0.0001). A positive correlation was also seen between the HIF-1α and VEGF expression (p = 0.347, p = 0.0001). However no correlation of HIF-1α, VEGF and Ang-2 was seen with portal vein thrombosis, cirrhosis, etiology, AST, ALT, and platelets.

Conclusions: HIF-1α and VEGF were highly expressed in HCC patients and may be responsible for the HCC growth. Further studies with a larger number of patients need to be done.

No significant financial relationships to disclose.

Comparison of 7 staging systems in north Indian cohort of hepatocellular carcinoma

BACKGROUND & AIM

Many liver staging systems have been proposed for patients with hepatocellular carcinoma (HCC); however it is still controversial which staging system is best. The aim of this study was to compare the ability of 7 different staging systems in predicting survival in an Indian cohort of patients with HCC.

METHODS

In this prospective study, 101 HCC patients were diagnosed and stratified according to 7 different staging systems; along with analysis of independent predictors of survival and their correlation with it (Kaplan-Meier analysis).

RESULTS

CLIP, Tokyo score and BCLC staging system showed a significant difference in the probability of survival. All other staging systems failed to show a significant difference in survival. Age, portal vein thrombosis, serum bilirubin, MELD score showed a significant difference with survival in univariate analysis. However, serum bilirubin was the independent predictor of survival with a hazard ratio of 1.609 (95% CI 1.015-2.553, p = 0.043).

CONCLUSION

The CLIP, Tokyo score and BCLC are the most useful staging systems in an Indian cohort.

Clinical utility of prothrombin induced by vitamin K absence in the detection of hepatocellular carcinoma in Indian population

BACKGROUND

Alpha-fetoprotein (AFP) is a well known widely used biomarker for the detection of hepatocellular carcinoma (HCC); however, it suffers from a low sensitivity and specificity. Protein or prothrombin induced by vitamin K absence or antagonist II (PIVKA-II) is another tumor marker elevated in HCC but not extensively used.

AIM

Evaluation of PIVKA-II and AFP in diagnosing HCC in India.

PATIENTS AND METHODS

The study group consisted of 70 consecutive HCC patients, 38 patients with cirrhosis, 30 patients with chronic hepatitis, and 30 normal healthy subjects. All patients were evaluated for PIVKA-II and AFP levels by ELISA.

RESULT

The mean plasma concentration of PIVKA-II in HCC, cirrhotic, chronic hepatitis patients and healthy controls was 101.07 ± 78.30 ng/ml, 2.45 ± 4.25 ng/ml, 1.50 ± 0.98 ng/ml and 0.79 ± 0.75 ng/ml, respectively. Receiver operating characteristic (ROC) curve was plotted for PIVKA-II and AFP. At a cutoff level of 9.2 ng/ml for PIVKA-II a sensitivity of 80% and a specificity of 92.1% was found, whereas AFP at a cutoff level of 13.02 ng/ml showed 72.9% sensitivity and 65.8% specificity. No significant relationship of plasma levels of PIVKA-II was observed in HCC with HBsAg/antiHCV positivity and associated portal vein thrombosis, but a positive correlation was seen with the tumor size (P = 0.001). However, no such significant association was found with AFP.

CONCLUSION

PIVKA-II was more sensitive and specific than AFP for diagnosing HCC in the Indian population.

Clinical significance of genotypes and precore/basal core promoter mutations in HBV related chronic liver disease patients in North India

PURPOSE

Data on genotypes, basal core promoter (BCP) and precore mutants of hepatitis B virus and their association with different HBV related liver disease have been studied inadequately and are controversial. Thus, the aim of this study was to determine the incidence of BCP and precore HBV mutants and their relationship with HBV genotype and different stages of HBV related liver disease in North Indian patients.

METHODS

A total 273 patients with different stages of HBV related liver diseases were enrolled. Nested polymerase chain reaction (PCR) was used to amplify the BCP/PC regions. RFLP and direct sequencing were performed to validate the mutations identified in these regions. HBV genotyping was accomplished by multiplex PCR.

RESULTS

Genotype D was the predominant genotype found in each of the various HBV related liver diseases. The BCP mutation was found significantly more often in inactive carriers and compensated cirrhosis as compared to the other groups. The BCP mutation was present in 29.1% of patients with genotype D versus 17.1% with genotype A (P = 0.001). The precore mutation was also more frequently observed with genotype D compared with genotype A (36.9 vs. 4.8%, P = 0.0007).

CONCLUSION

Genotype D is predominant in North Indian patients. The BCP and precore mutations occur in one-third of HBV positive patients in association with the genotype D. We did not find any correlation with severity of liver disease with genotypes and mutations.

Vitamin D nutritional status of exclusively breast fed infants and their mothers

BACKGROUND

Vitamin D nutrition has a profound effect on the development of an infant. Vitamin D status of mothers and their infants are closely correlated. While hypovitaminosis D has emerged as a significant public health problem across all age groups, there is limited information of this condition in lactating mothers and their breast fed infants.

AIM

To evaluate the vitamin D status of lactating mothers and their breast fed infants.

SUBJECTS AND METHODS

180 healthy lactating mothers and exclusively breast fed infants, 2-24 weeks old, were recruited for the study. The mother-infant pairs underwent concurrent clinical, biochemical and hormonal evaluation for calcium-vitamin D-PTH axis.

RESULTS

The mean serum 25(OH)D values in lactating mothers was 27.2 +/- 14.6 nmol/l (10.9 +/- 5.8 ng/ml), while that of their infants was 28.9 +/- 20.8 nmol/l (11.6 +/- 8.3 ng/ml). Serum 25(OH)D levels <25 nmol/l (10 ng/ml) were found in 47.8% of the mothers and 43.2% of the infants. Among these, elevated PTH levels (>54 pg/ml) were seen in 59.3% of the mothers and 69.6% of the infants. A highly significant negative correlation was found between serum 25(OH)D and PTH in mothers (r = -0.480, p = 0.01) and their infants (r = -0.431, p = 0.01). A strong positive correlation was seen of 25(OH)D levels in mother-infant pairs (r = 0.324, p = 0.001).

CONCLUSIONS

A high prevalence of vitamin D deficiency was found in lactating mothers and their exclusively breast fed infants. Infants born to mothers with hypovitaminosis D had 3.8 times higher risk of developing hypovitaminosis D as compared to those born to mothers with normal vitamin D levels.

Measuring Surface Hydrophobicity as Compared to Measuring a Hydrophobic Effect on Adhesion Events

Simple contact-angle methods are commonly used to describe surface influences on phenomena including adsorption, adhesion, fouling, and cleaning, However, for the purpose of quantitatively relating surface hydrophobicity to such phenomena, contact-angle analysis may be insufficient. Here we show that even with model hydrophobic and hydrophilic surfaces, measurement of the effect of surface hydrophobicity on adsorption of the antimicrobial proteins nisin and bacteriophage T4 lysozyme yielded conflicting results, apparently because different mechanisms govern events at the interface, depending on surface hydrophobicity. This finding is explained in terms of the presence of two competing mechanisms for attractive associations at these surfaces: hydrophobic and attractive electrostatic associations.