Galectin-3 Activation and Inhibition in Heart Failure and Cardiovascular Disease: An Update

Galectin-3 is a versatile protein orchestrating several physiological and pathophysiological processes in the human body. In the last decade, considerable interest in galectin-3 has emerged because of its potential role as a biotarget. Galectin-3 is differentially expressed depending on the tissue type, however its expression can be induced under conditions of tissue injury or stress. Galectin-3 overexpression and secretion is associated with several diseases and is extensively studied in the context of fibrosis, heart failure, atherosclerosis and diabetes mellitus. Monomeric (extracellular) galectin-3 usually undergoes further "activation" which significantly broadens the spectrum of biological activity mainly by modifying its carbohydrate-binding properties. Self-interactions of this protein appear to play a crucial role in regulating the extracellular activities of this protein, however there is limited and controversial data on the mechanisms involved. We therefore summarize (recent) literature in this area and describe galectin-3 from a binding perspective providing novel insights into mechanisms by which galectin-3 is known to be "activated" and how such activation may be regulated in pathophysiological scenarios.

The intrinsically disordered N-terminal domain of galectin-3 dynamically mediates multisite self-association of the protein through fuzzy interactions

Galectins are a family of lectins that bind β-galactosides through their conserved carbohydrate recognition domain (CRD) and can induce aggregation with glycoproteins or glycolipids on the cell surface and thereby regulate cell activation, migration, adhesion, and signaling. Galectin-3 has an intrinsically disordered N-terminal domain and a canonical CRD. Unlike the other 14 known galectins in mammalian cells, which have dimeric or tandem-repeated CRDs enabling multivalency for various functions, galectin-3 is monomeric, and its functional multivalency therefore is somewhat of a mystery. Here, we used NMR spectroscopy, mutagenesis, small-angle X-ray scattering, and computational modeling to study the self-association-related multivalency of galectin-3 at the residue-specific level. We show that the disordered N-terminal domain (residues ∼20-100) interacts with itself and with a part of the CRD not involved in carbohydrate recognition (β-strands 7-9; residues ∼200-220), forming a fuzzy complex via inter- and intramolecular interactions, mainly through hydrophobicity. These fuzzy interactions are characteristic of intrinsically disordered proteins to achieve liquid-liquid phase separation, and we demonstrated that galectin-3 can also undergo liquid-liquid phase separation. We propose that galectin-3 may achieve multivalency through this multisite self-association mechanism facilitated by fuzzy interactions.

Applying Pattern Recognition to High-Resolution Images to Determine Cellular Signaling Status

Two frequently used tools to acquire high- resolution images of cells are scanning electron microscopy (SEM) and atomic force microscopy (AFM). The former provides a nanometer resolution view of cellular features rapidly and with high throughput, while the latter enables visualizing hydrated and living cells. In current practice, these images are viewed by eye to determine cellular status, e.g., activated versus resting. Automatic and quantitative data analysis is lacking. This paper develops an algorithm of pattern recognition that works very effectively for AFM and SEM images. Using rat basophilic leukemia cells, our approach creates a support vector machine to automatically classify resting and activated cells. Ten-fold cross-validation with cells that are known to be activated or resting gives a good estimate of the generalized classification results. The pattern recognition of AFM images achieves 100% accuracy, while SEM reaches 95.4% for our images as well as images published in prior literature. This outcome suggests that our methodology could become an important and frequently used tool for researchers utilizing AFM and SEM for structural characterization as well as determining cellular signaling status and function.

Population structure of Han Chinese in the modern Taiwanese population based on 10,000 participants in the Taiwan Biobank project

The Taiwan Biobank (TWB) aims to build a nationwide research database that integrates genomic/epigenomic profiles, lifestyle patterns, dietary habits, environmental exposure history and long-term health outcomes of 300,000 residents of Taiwan. We describe here an investigation of the population structure of Han Chinese on this Pacific island using genotype data of 591,048 SNPs in an initial freeze of 10,801 unrelated TWB participants. In addition to the North-South cline reported in other Han Chinese populations, we find the Taiwanese Han Chinese clustered into three cline groups: 5% were of northern Han Chinese ancestry, 79.9% were of southern Han Chinese ancestry, and 14.5% belonged to a third (T) group. We also find that this T group is genetically distinct from neighbouring Southeast Asians and Austronesian tribes but similar to other southern Han Chinese. Interestingly, high degree of LD between HLA haplotype A*33:03-B*58:01, an MHC allele being of pathological relevance, and SNPs across the MHC region was observed in subjects with T origin, but not in other Han Chinese. This suggested the T group individuals may have experienced evolutionary events independent from the other southern Han Chinese. Based on the newly-discovered population structure, we detect different loci susceptible to type II diabetes in individuals with southern and northern Han Chinese ancestries. Finally, as one of the largest dataset currently available for the Chinese population, genome-wide statistics for the 10,810 subjects are made publicly accessible through Taiwan View (https://taiwanview.twbiobank.org.tw/index; date last accessed October 14, 2016) to encourage future genetic research and collaborations with the island Taiwan.

Cell Intrinsic Galectin-3 Attenuates Neutrophil ROS-Dependent Killing of Candida by Modulating CR3 Downstream Syk Activation

Invasive candidiasis is a leading cause of nosocomial bloodstream infection. Neutrophils are the important effector cells in host resistance to candidiasis. To investigate the modulation of neutrophil fungicidal function will advance our knowledge on the control of candidiasis. While recombinant galectin-3 enhances neutrophil phagocytosis of Candida, we found that intracellular galectin-3 downregulates neutrophil fungicidal functions. Co-immunoprecipitation and immunofluorescence staining reveal that cytosolic gal3 physically interacts with Syk in neutrophils after Candida stimulation. Gal3^−/− neutrophils have higher level of Syk activation as well as greater abilities to generate reactive oxygen species (ROS) and kill Candida than gal3^+/+ cells. While galectin-3 deficiency modulates neutrophil and macrophage activation and the recruitment of monocytes and dendritic cells, the deficiency does not affect the numbers of infiltrating neutrophils or macrophages. Galectin-3 deficiency ameliorates systemic candidiasis by reducing fungal burden, renal pathology, and mortality. Adoptive transfer experiments demonstrate that cell intrinsic galectin-3 negatively regulates neutrophil effector functions against candidiasis. Reducing galectin-3 expression or activity by siRNA or gal3 inhibitor TD139 enhances human neutrophil ROS production. Mice treated with TD139 have enhanced ability to clear the fungus. Our work unravels the mechanism by which galectin-3 regulates Syk-dependent neutrophil fungicidal functions and raises the possibility that blocking gal3 in neutrophils may be a promising therapeutic strategy for treating systemic candidiasis.

Generation and characterization of new monoclonal antibodies against swine origin 2009 influenza A (H1N1) virus and evaluation of their prophylactic and therapeutic efficacy in a mouse model

In 2009, a swine-origin influenza A virus - A(H1N1)pdm09 - emerged and has became a pandemic strain circulating worldwide. The hemagglutinin (HA) of influenza virus is a potential target for the development of anti-viral therapeutic agents. Here, we generated mAbs by immunization of baculovirus-insect expressing trimeric recombinant HA of the A(H1N1)pdm09 strain. Results indicated that the mAbs recognized two novel neutralizing and protective epitopes-"STAS" and "FRSK" which located near Cb and Ca1 antigenic regions respectively and were conserved in almost 2009-2016 influenza H1N1 stains. The mAb 12E11 demonstrated higher protective efficacy than mAb 8B10 in mice challenge assay. Both mAb pretreatments significantly reduced virus titers and pro-inflammatory cytokines in mice lung postinfection (p < 0.01), and showed prophylactic and therapeutic efficacies even 48 h postinfection (p < 0.05). Combination therapy using the mAbs with oseltamivir pre- and post-treatment showed synergistic therapeutic effect in mice model (p < 0.01). Further investigation for clinical application in humans is warranted.

Galectin-3 and Its Genetic Variation rs4644 Modulate Enterovirus 71 Infection

Galectin-3, a chimeric type β-galactoside-binding protein, is known to modulate viral infection; however, its role in enterovirus 71 (EV71) infection has not been investigated. We generated galectin-3 null rhabdomyosarcoma (RD) cells and evaluated whether EV71 infection would be affected. In galectin-3 null cells, the released and intracellular EV71 viral loads were suppressed after 24 h of infection, and cell death rates were significantly lower, while cell proliferation remained unaltered. In addition, RD cells expressing a nonsynonymous genetic variant of galectin-3, rs4644 (LGALS3 +191C/A, P64H), produced lower virus titers than those with wild-type galectin-3 (C allele). To clarify whether the in vitro viral load reduction correlates with clinical severity, we enrolled children with laboratory-confirmed EV71 infection. Since hyperglycemia is an indicator of severe EV71 infection in children, 152 of 401 enrolled children had glucose examinations at admission, and 59 subjects had serum glucose levels ≥ 150 mg/dL. In comparison to the rs4644 AA genotype (2.2 ± 0.06 log10 mg/dL), serum glucose levels during EV71 infection were higher in patients with CC (2.4 ± 0.17 log10 mg/dL, p = 0.03) and CA (2.4 ± 0.15 log10 mg/dL, p = 0.02) genotypes, respectively. These findings suggest that the rs4644 AA genotype of galectin-3 might exert a protective effect. In summary, galectin-3 affects EV71 replication in our cellular model and its variant, rs4644, is associated with hyperglycemia in the clinical setting. The underlying mechanism and its potential therapeutic application warrant further investigation.

Nanoimaging granule dynamics and subcellular structures in activated mast cells using soft X-ray tomography

Mast cells play an important role in allergic responses. During activation, these cells undergo degranulation, a process by which various kinds of mediators stored in the granules are released. Granule homeostasis in mast cells has mainly been studied by electron microscopy (EM), where the fine structures of subcellular organelles are partially destroyed during sample preparation. Migration and fusion of granules have not been studied in detail in three dimensions (3D) in unmodified samples. Here, we utilized soft X-ray tomography (SXT) coupled with fluorescence microscopy to study the detailed structures of organelles during mast cell activation. We observed granule fission, granule fusion to plasma membranes, and small vesicles budding from granules. We also detected lipid droplets, which became larger and more numerous as mast cells were activated. We observed dramatic morphological changes of mitochondria in activated mast cells and 3D-reconstruction revealed the highly folded cristae inner membrane, features of functionally active mitochondria. We also observed giant vesicles containing granules, mitochondria, and lipid droplets, which we designated as granule-containing vesicles (GCVs) and verified their presence by EM in samples prepared by cryo-substitution, albeit with a less clear morphology. Thus, our studies using SXT provide significant insights into mast cell activation at the organelle level.

Galectin-3 regulates inflammasome activation in cholestatic liver injury

Macrophage activation is an important feature of primary biliary cholangitis (PBC) pathogenesis and other cholestatic liver diseases. Galectin-3 (Gal3), a pleiotropic lectin, is produced by monocytic cells and macrophages. However, its role in PBC has not been addressed. We hypothesized that Gal3 is a key to induce NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome in macrophages and in turn to propagate proinflammatory IL-17 signaling. In liver tissues from patients with PBC and dnTGF-βRII mice, a model of autoimmune cholangitis, the expression of Gal3, NLRP3, and the adaptor protein adaptor apoptosis-associated speck-like protein was induced, with the downstream activation of caspase-1 and IL-1β. In wild-type hepatic macrophages, deoxycholic acid induced the association of Gal3 and NLRP3 with direct activation of the inflammasome, resulting in an increase in IL-1β. Downstream retinoid-related orphan receptor C mRNA, IL-17A, and IL-17F were induced. In Gal3^-/- macrophages, no inflammasome activation was detected. To confirm the key role of Gal3 in the pathogenesis of cholestatic liver injury, we generated dnTGF-βRII/galectin-3^-/- (dn/Gal3^-/-) mice, which showed impaired inflammasome activation along with significantly improved inflammation and fibrosis. Taken together, our data point to a novel role of Gal3 as an initiator of inflammatory signaling in autoimmune cholangitis, mediating the activation of NLRP3 inflammasome and inducing IL-17 proinflammatory cascades. These studies provide a rationale to target Gal3 in autoimmune cholangitis and potentially other cholestatic diseases.-Tian, J., Yang, G., Chen, H.-Y., Hsu, D. K., Tomilov, A., Olson, K. A., Dehnad, A., Fish, S. R., Cortopassi, G., Zhao, B., Liu, F.-T., Gershwin, M. E., Török, N. J., Jiang, J. X. Galectin-3 regulates inflammasome activation in cholestatic liver injury.

Dual thio-digalactoside-binding modes of human galectins as the structural basis for the design of potent and selective inhibitors

Human galectins are promising targets for cancer immunotherapeutic and fibrotic disease-related drugs. We report herein the binding interactions of three thio-digalactosides (TDGs) including TDG itself, TD139 (3,3'-deoxy-3,3'-bis-(4-[m-fluorophenyl]-1H-1,2,3-triazol-1-yl)-thio-digalactoside, recently approved for the treatment of idiopathic pulmonary fibrosis), and TAZTDG (3-deoxy-3-(4-[m-fluorophenyl]-1H-1,2,3-triazol-1-yl)-thio-digalactoside) with human galectins-1, -3 and -7 as assessed by X-ray crystallography, isothermal titration calorimetry and NMR spectroscopy. Five binding subsites (A-E) make up the carbohydrate-recognition domains of these galectins. We identified novel interactions between an arginine within subsite E of the galectins and an arene group in the ligands. In addition to the interactions contributed by the galactosyl sugar residues bound at subsites C and D, the fluorophenyl group of TAZTDG preferentially bound to subsite B in galectin-3, whereas the same group favored binding at subsite E in galectins-1 and -7. The characterised dual binding modes demonstrate how binding potency, reported as decreased Kd values of the TDG inhibitors from μM to nM, is improved and also offer insights to development of selective inhibitors for individual galectins.

Galectin-12 inhibits granulocytic differentiation of human NB4 promyelocytic leukemia cells while promoting lipogenesis

As a member of the galectin family of animal lectins, galectin-12 is preferentially expressed in adipocytes and leukocytes. In adipocytes, galectin-12 is associated with lipid droplets and regulates lipid metabolism and energy balance, whereas its role in leukocytes is not clear. Analysis of galectin-12 expression in a public data set of acute myeloid leukemia (AML) samples revealed that it is selectively overexpressed in the M3 subtype, which is also known as acute promyelocytic leukemia (APL). To investigate the role of galectin-12 in APL cells, we manipulated its expression in the APL cell line, NB4, and measured resultant effects on all-trans-retinoic acid (ATRA)-induced granulocytic differentiation. With a doxycycline-inducible gene knockdown system, we found that suppression of galectin-12 promoted ATRA-induced neutrophil differentiation but inhibited lipid droplet formation. Our results indicate that overexpression of galectin-12 contributes to a differentiation block in APL cells, and suppression of galectin-12 facilitates granulocytic differentiation. Furthermore, these data suggest that lipogenesis and other aspects of myeloid differentiation can be differentially regulated. Taken together, these findings suggest that galectin-12 may be a target for treatment of the ATRA-resistant subset of APL.

Galectin-7 Regulates Keratinocyte Proliferation and Differentiation through JNK-miR-203-p63 Signaling

Galectin-7, a member of the β-galactoside-binding protein family, is primarily expressed in stratified epithelial cells, including keratinocytes. There is information in the literature suggesting a role for this protein in regulation of keratinocyte survival and growth, but the underlying mechanism remains relatively unknown. Moreover, its expression pattern in the epidermis suggests that it is also involved in the regulation of keratinocyte differentiation. Here, we demonstrate that galectin-7 knockdown results in reduced differentiation and increased proliferation of keratinocytes. Using microarray and deep-sequencing analyses, we found that galectin-7 positively and negatively regulates microRNA (miR)-203 and miR-146a expression, respectively. We show that galectin-7 regulates keratinocyte differentiation and proliferation through miR-203 but not miR-146a. A knockdown of either galectin-7 or miR-203 in keratinocytes increases expression of p63, an essential transcription factor involved in skin development. Rescue of miR-203 expression in a galectin-7 knockdown model reduces p63 expression to baseline. Increased galectin-7 expression upregulates c-Jun N-terminal kinase (JNK) protein levels, which is required for miR-203 expression. Finally, we establish that galectin-7 can be associated with JNK1 and protect it from ubiquitination and degradation. Thus, our data suggest an intracellular function of galectin-7: regulation of keratinocyte proliferation and differentiation through the JNK1-miR-203-p63 pathway.

Nanoimaging granule dynamics and subcellular structures in activated mast cells using soft X-ray tomography

Mast cells play an important role in allergic responses. During activation, these cells undergo degranulation, a process by which numerous mediators stored in the granules are released. Granule homeostasis in mast cells has mainly been studied by electron microscopy (EM), where the fine structures of subcellular organelles are partially destroyed during sample preparation. Migration and fusion of granules have not been studied in detail in three dimensions (3D) in unmodified samples. Here, we utilized soft X-ray tomography (SXT) coupled with fluorescence microscopy to study the detailed structures of organelles during mast cell activation. We observed granule fission, granule fusion to plasma membranes, and small vesicles budding from granules. We also detected lipid droplets, which become larger and more numerous as mast cells become activated. We observed dramatic morphological changes of mitochondria in activated mast cells and 3D-reconstruction revealed the highly folded cristae inner membrane, features of functionally active mitochondria. We also observed giant vesicles containing granules, mitochondria, and lipid droplets, which we designated as granule-containing vesicles (GCVs), and we verified their presence by EM in samples prepared by cryo-substitution, albeit with a less clear morphology. Thus, our studies using SXT provide significant insights into mast cell activation at the organelle level.

Identification of VPS13C as a Galectin-12-Binding Protein That Regulates Galectin-12 Protein Stability and Adipogenesis

Galectin-12, a member of the galectin family of β-galactoside-binding animal lectins, is preferentially expressed in adipocytes and required for adipocyte differentiation in vitro. This protein was recently found to regulate lipolysis, whole body adiposity, and glucose homeostasis in vivo. Here we identify VPS13C, a member of the VPS13 family of vacuolar protein sorting-associated proteins highly conserved throughout eukaryotic evolution, as a major galectin-12-binding protein. VPS13C is upregulated during adipocyte differentiation, and is required for galectin-12 protein stability. Knockdown of Vps13c markedly reduces the steady-state levels of galectin-12 by promoting its degradation through primarily the lysosomal pathway, and impairs adipocyte differentiation. Our studies also suggest that VPS13C may have a broader role in protein quality control. The regulation of galectin-12 stability by VPS13C could potentially be exploited for therapeutic intervention of obesity and related metabolic diseases.

Glycolic Acid Silences Inflammasome Complex Genes, NLRC4 and ASC, by Inducing DNA Methylation in HaCaT Cells

AHAs (α-hydroxy acids), including glycolic acid (GA), have been widely used in cosmetic products and superficial chemical peels. Inflammasome complex has been shown to play critical roles in inflammatory pathways in human keratinocytes. However, the anti-inflammatory mechanism of GA is still unknown. The aim of this study is to investigate the relationship between the expression of the inflammasome complex and epigenetic modification to elucidate the molecular mechanism of the anti-inflammatory effect of GA in HaCaT cells. We evaluated NLRP3, NLRC4, AIM2, and ASC inflammasome complex gene expression on real-time polymerase chain reaction (PCR). Methylation changes were detected in these genes following treatment with DNA methyltransferase (DNMT) inhibitor 5-aza-2'-deoxycytidine (5-Aza) with or without the addition of GA using methylation-specific PCR (MSP). GA inhibited the expressions of these inflammasome complex genes, and the decreases in the expressions of mRNA were reversed by 5-Aza treatment. Methylation was detected in NLRC4 and ASC on MSP, but not in NLRP3 or AIM2. GA decreased NLRC4 and ASC gene expression by increasing not only DNA methyltransferase 3B (DNMT-3B) protein level, but also total DNMT activity. Furthermore, silencing of DNMT-3B (shDNMT-3B) increased the expressions of NLRC4 and ASC. Our data demonstrated that GA treatment induces hypermethylation of promoters of NLRC4 and ASC genes, which may subsequently lead to the hindering of the assembly of the inflammasome complex in HaCaT cells. These results highlight the anti-inflammatory potential of GA-containing cosmetic agents in human skin cells and demonstrate for the first time the role of aberrant hypermethylation in this process.

Galectin-12 enhances inflammation by promoting M1 polarization of macrophages and reduces insulin sensitivity in adipocytes

Galectin-12 is a member of an animal lectin family with affinity for β-galactosides and containing consensus amino acid sequences. Here, we found that galectin-12 was expressed in macrophages and thus aimed to determine how galectin-12 affects inflammation and macrophage polarization and activation. The ablation of galectin-12 did not affect bone marrow cells to differentiate into macrophages, but reduced phagocytic activity against Escherichia coli and lowered the secretion of nitric oxide. The ablation of galectin-12 also resulted in the polarization of macrophages into the M2 direction, as indicated by increases in the levels of M2 markers, namely, resistin-like β (FIZZ1) and chitinase 3-like 3 (Ym1), as well as a reduction in the expression levels of a number of M1 pro-inflammatory cytokines. We found that the diminished expression of pro-inflammatory cytokines in macrophages resulting from galectin-12 deletion was due to reduced activation of IKKα/β, Akt and ERK, which in turn caused decreased activation of NF-κB and activator protein 1. The activation of STAT3 was much higher in Gal12(-/-) macrophages activated by lipopolysaccharide, which was correlated with higher levels of IL-10. Adipocytes showed higher insulin sensitivity when treated with Gal12(-/-) macrophage-conditioned media than those treated with Gal12(+/+) macrophages. We conclude galectin-12 negatively regulates macrophage polarization into the M2 population, resulting in enhanced inflammatory responses and also in turn causing decreased insulin sensitivity in adipocytes. This has implications in the treatment of a wide spectrum of metabolic disorders.

Galectin-3 modulates the EGFR signalling-mediated regulation of Sox2 expression via c-Myc in lung cancer

Galectin-3 is a ubiquitous lectin exerting multiple cellular functions such as RNA splicing, protein trafficking and apoptosis. Its expression is positively correlated with the poor prognosis in lung cancer patients. Galectin-3 can promote cancer progression through its effects on cell proliferation, cell survival or cancer metastasis. However, the role of galectin-3 in the regulation of cancer stem-like cells (CSCs) is still unclear. Here, we investigated the hypothesis that galectin-3 might regulate lung CSCs via the EGF receptor (EGFR) signaling pathway. In our study, galectin-3 facilitated EGFR activation and enhanced the sphere formation activity of lung cancer cells. Furthermore, galectin-3 promoted Sox2 expression in an EGFR activation-dependent manner; importantly, forced expression of Sox2 blunted the effect of galectin-3 knockdown on lung cancer sphere formation ability. These results suggest that galectin-3 promotes EGFR activation leading to the upregulation of Sox2 expression and lung CSCs properties. Moreover, we showed that the carbohydrate-binding activity of galectin-3 was important for the regulation of EGFR activation, Sox2 expression and sphere formation. We have recently reported that c-Myc is a transcriptional activator of Sox2. We further found that galectin-3 enhanced c-Myc protein stability leading to increased c-Myc binding to the Sox2 gene promoter. We also examined the effect of the stemness factors, Oct4, Nanog and Sox2 on the expression of galectin-3. We found that Oct4 enhanced galectin-3 expression. Our results together suggest that galectin-3 enhances lung cancer stemness through the EGFR/c-Myc/Sox2 axis; Oct4, in turn, promotes galectin-3 expression, forming a positive regulatory loop in lung CSCs.

Galectin 3 regulates HCC cell invasion by RhoA and MLCK activation

Hepatocellular carcinoma (HCC) carries a poor prognosis with no effective treatment available other than liver transplantation for selected patients. Vascular invasion of HCC is one of the most important negative predictor of survival. As the regulation of invasion of HCC cells is not well understood, our aim was to study the mechanisms by which galectin 3, a β-galactosidase-binding lectin mediates HCC cell migration. HCC was induced by N-diethylnitrosamine in wild-type and galectin 3(-/-) mice, and tumor formation, histology, and tumor cell invasion were assessed. The galectin 3(-/-) mice developed significantly smaller tumor burden with a less invasive phenotype than the wild-type animals. Galectin 3 was upregulated in the wild-type HCC tumor tissue, but not in the surrounding parenchyma. Galectin 3 expression in HCC was induced by NF-κB transactivation as determined by chromatin immunoprecipitation assays. In vitro studies assessed the pro-migratory effects of galectin 3. The migration of hepatoma cells was significantly decreased after transfection by the galectin 3 siRNA and also after using the Rho kinase inhibitor Y-27632. The reorganization of the actin cytoskeleton, RhoA GTPase activity and the phosphorylation of MLC2 (myosin light chain 2) were decreased in the galectin 3 siRNA-transfected cells. In addition, in vitro and in vivo evidence showed that galectin 3 deficiency reduced hepatoma cell proliferation and increased their apoptosis rate. In conclusion, galectin 3 is an important lectin that is induced in HCC cells, and promotes hepatoma cell motility and invasion by an autocrine pathway. Targeting galectin 3 therefore could be an important novel treatment strategy to halt disease progression.

Engineered Nanostructures of Haptens Lead to Unexpected Formation of Membrane Nanotubes Connecting Rat Basophilic Leukemia Cells

A recent finding reports that co-stimulation of the high-affinity immunoglobulin E (IgE) receptor (FcεRI) and the chemokine receptor 1 (CCR1) triggered formation of membrane nanotubes among bone-marrow-derived mast cells. The co-stimulation was attained using corresponding ligands: IgE binding antigen and macrophage inflammatory protein 1α (MIP1 α), respectively. However, this approach failed to trigger formation of nanotubes among rat basophilic leukemia (RBL) cells due to the lack of CCR1 on the cell surface (Int. Immunol. 2010, 22 (2), 113-128). RBL cells are frequently used as a model for mast cells and are best known for antibody-mediated activation via FcεRI. This work reports the successful formation of membrane nanotubes among RBLs using only one stimulus, a hapten of 2,4-dinitrophenyl (DNP) molecules, which are presented as nanostructures with our designed spatial arrangements. This observation underlines the significance of the local presentation of ligands in the context of impacting the cellular signaling cascades. In the case of RBL, certain DNP nanostructures suppress antigen-induced degranulation and facilitate the rearrangement of the cytoskeleton to form nanotubes. These results demonstrate an important scientific concept; engineered nanostructures enable cellular signaling cascades, where current technologies encounter great difficulties. More importantly, nanotechnology offers a new platform to selectively activate and/or inhibit desired cellular signaling cascades.

Successful treatment of psoriasis with ustekinumab in patients with multiple sclerosis

Psoriasis is a chronic inflammatory disease, evolving from a complex interplay of genetic and environmental factors. In the recent years, we have seen much progress in understanding the immunopathogenesis of psoriasis, paving the way for new therapies with biologics. Currently, the most commonly used biologics in psoriasis are TNF inhibitors etanercept, infliximab and adalimumab, and the IL-12/23 inhibitor ustekinumab. As TNF inhibitors are contraindicated in patients with multiple sclerosis, ustekinumab remained the only biologic available for these patient before the recent approval of Secukinumab, an IL-17A inhibitor. Herein we report two patients with multiple sclerosis and comorbid psoriasis successfully treated with ustekinumab without progression of their multiple sclerosis. Our cases demonstrate that ustekinumab is a reasonably safe choice in this patient population. We also briefly reviewed new therapies currently under investigation, which will undoubtedly further expand our armamentarium for the treatment of psoriasis in patients with neuromuscular diseases.

Association of STAT6 genetic variants with childhood atopic dermatitis in Taiwanese population

BACKGROUND

Atopic dermatitis (AD) is the single most common allergic disease in children. STAT6 has been noted as a hub molecule in IL-4 mediated response and AD pathogenesis. However, the association between STAT6 genetic variants and childhood AD has never been thoroughly examined.

OBJECTIVE

We investigate the association between STAT6 genetic variants and childhood AD risk in Taiwanese population.

METHODS

We used data from the Han Chinese in Beijing genome panel of International HapMap Project and the Taiwan Children Health Study cohort to investigate the association of STAT6 genetic variants and childhood AD risks. Four tagged SNPs were selected from HapMap database and rs324011 was most significantly associated with childhood AD. Subsequently, deep sequencing around rs324011 and unconditional/conditional logistic models were applied.

RESULTS

rs324011 showed statistical significance for the occurrence of childhood AD (OR: 1.23; 95% CI: 1.01-1.51) and rs167769 showed borderline statistical significance (OR: 1.21; 95% CI: 0.99-1.49). Likelihood ratio tests revealed that haplotypes (rs167769/rs324011) were associated with childhood AD (global p=0.0018). T alleles of two STAT6 intron2 SNPs, rs324011 and rs167769, increased STAT6 promoter activity significantly in luciferase reporter assay.

CONCLUSION

T allele of rs324011 in STAT6 would increase the risk of AD occurrence in children. Haplotypes of rs324011/rs167769 were also significantly associated with childhood AD in Taiwanese population.

Patient-centered, direct-access online care for management of atopic dermatitis: a randomized clinical trial

IMPORTANCE

New models of health care delivery for dermatological care have the potential to increase access and improve patient-centered outcomes.

OBJECTIVE

To compare effectiveness of a direct-access, online model for follow-up dermatologic care in pediatric and adult patients with atopic dermatitis with that of in-person office visits.

DESIGN, SETTING, AND PARTICIPANTS

This was a 1-year, randomized controlled equivalency clinical trial in medically underserved areas, outpatient clinics, and the general community. Participants included children and adults with atopic dermatitis with access to the Internet, computers, and digital cameras.

INTERVENTIONS

After an initial in-person visit, patients were randomized 1:1 to direct-access online or usual in-person care for follow-up management of atopic dermatitis. In the direct-access online group, patients captured and transmitted clinical images and history asynchronously to dermatologists online; dermatologists evaluated the clinical information, provided recommendations and education, and prescribed medications online asynchronously. In the in-person group, patients visited dermatologists in their offices for follow-up care.

MAIN OUTCOMES AND MEASURES

Atopic dermatitis disease severity as assessed by patient-oriented eczema measure (POEM) and investigator global assessment (IGA).

RESULTS

A total of 156 children and adults were randomized. Between baseline and 12 months, the mean (SD) within-group difference in POEM score in patients in the direct-access online group was -5.1 (5.48) (95% CI, -6.32 to -3.88); in the in-person group, the within-group difference was -4.86 (4.87) (95% CI, -6.27 to -3.46). The difference in the change in POEM scores between the 2 groups was 0.24 (6.59) (90% CI, -1.70 to 1.23), which was contained within the predetermined 2.5 equivalence margin. The percentage of patients achieving clearance or near-clearance of their disease (IGA score of 0 or 1) was 38.4% (95% CI, 27.7% to 49.3%) in the direct-access online group and 43.6% (95% CI, 32.6%-54.6%) in the in-person group. The difference in the percent of patients achieving clearance or near-clearance between the 2 groups was 5.1% (90% CI, 1.7%-8.6%), which was contained within the predetermined 10% equivalence margin.

CONCLUSIONS AND RELEVANCE

The direct-access online model results in equivalent improvements in atopic dermatitis clinical outcomes as in-person care. Direct-access online care may represent an innovative model of delivering dermatological services to patients with chronic skin diseases.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00985894.

Molecular cloning and tissue distribution profiles of the chicken R-spondin1 gene

Rspo1 belongs to the Rspo family, which is composed of 4 members (Rspo1-4) that share 40 to 60% sequence homology and similar domain organizations, and regulate the WNT signaling pathway via a common mechanism. Rspo1 plays a key role in vertebrate development and is an effective mitogenic factor of gastrointestinal epithelial cells. We report the cloning of chicken Rspo1 and its gene expression distribution among tissues. It contained an open reading frame of 783 bp encoding a protein of 260 amino acids, and its molecular weight was predicted to be 28.80 kDa. Reverse transcription-polymerase chain reaction-based gene expression analysis indicated that chicken Rspo1 was highly expressed in the stomach muscle tissue, but was expressed at low levels in the lung, brain, jejunum, cecum, ileum, spleen, pancreas, kidney, and glandular stomach. These results suggest that Rspo1 plays a major role in muscular immune protection.