Nutrient Responsive O-GlcNAcylation Dynamically Modulates Galectin 3 Secretion

Endomembrane glycosylation and cytoplasmic O-GlcNAcylation each play essential roles in nutrient sensing, and in fact, characteristic changes in glycan patterns have been described in disease states such as diabetes and cancer. These changes in glycosylation have important functional roles and can drive disease progression. However, little is known about the molecular mechanisms underlying how these signals are integrated and transduced into biological effects. Galectins are proteins that bind glycans that are secreted by a poorly characterized non-classical secretory mechanism. Once outside the cell, galectins bind to terminal galactose residues of cell surface glycans and modulate numerous extracellular functions like clathrin independent endocytosis (CIE). Originating in the cytoplasm, galectins are predicted substrates for O-GlcNAc addition and removal. This study shows that galectin 3 is O-GlcNAcylated, and that changes in O-GlcNAc cycling alters its secretion. Moreover, we determined that there is a significant difference in O-GlcNAcylation status between cytoplasmic and secreted galectin 3. We observed dramatic alterations in galectin 3 secretion in response to nutrient conditions and that these changes were dependent on dynamic O-GlcNAcylation. Finally, we showed that alterations in galectin 3 secretion via disrupted O-GlcNAcylation drove changes in CIE. These results indicate that dynamic O-GlcNAcylation of galectin 3 plays a role in modulating its secretion and can tune its function of transducing nutrient sensing information coded in cell surface glycosylation into biological effects.

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Altered Expressions of CD30, c-Jun N-Terminal Kinase, NF-κB and JunB Are Involved in Disease Progression in CD30-Positive Anaplastic Large Cell Lymphoma.

Blood ◽

10.1182/blood.v106.11.2827.2827 ◽

2005 ◽

Vol 106 (11) ◽

pp. 2827-2827

Author(s):

Tsuyoshi Nakamaki ◽

Hidetoshi Nakashima ◽

Masamichi Hattori ◽

Takako Usui ◽

Takashi Maeda ◽

...

Keyword(s):

Cell Surface ◽

Growth Inhibition ◽

Disease Progression ◽

Cell Lines ◽

Anaplastic Large Cell Lymphoma ◽

Cell Lymphoma ◽

Large Cell ◽

Cell Surface Expression ◽

Significant Difference ◽

Large Cell Lymphoma

Abstract Anaplastic large cell lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL) is an aggressive T cell lymphoma. CD30 is a characteristic cell surface protein overexpressed in ALCL cells as well as in malignant cells of Hodgkin lymphoma. CD30-mediated signals are molecular target(s) in the therapy for CD30-positive lymphoma. We studied molecular pathway(s) involved in the disease progression in two ALK- negative CD30-positive ALCL cell lines (N1, N2), which are recently established. In vitro culture, N1 and N2 represent early and advanced stage lymphoma phenotype, respectively. N2, compared to N1, was characterized by the increase of colony formation in soft agar more than 100 fold, the increase of cell surface expression of CD30 protein (p<0.0001) and the increase of activated (nuclear) NF- κB activities (p=0.0039). N2 showed significant decrease of cell surface expressions of co-stimulatory molecules such as CD80 and CD86 and decrease of adhesion molecules such as CD2, CD29 and CD49d, which suggest loss of these molecules are also involved in disease progression by allowing ALCL cells to escape immune systems of host against tumors and metastasize. Western blot analysis showed that N2 expressed CD30 protein with molecular weight of 100 Kd, whereas N1 expressed membrane molecule CD30 protein with 120Kd. These two different form of CD30 proteins were coimmunoprecipitated with TNF receptor-associated factor (TRAF)2 but not TRAF5, suggesting ligand-independent association of CD30 and TRAF2 has a function in CD30-mediated signal transduction in these cell lines. In both of N1 and N2, constitutive activation of AP-1 was demonstrated by gel shift analysis using AP-1 DNA consensus sequence. c-Jun N-terminal kinase (JNK) was highly phosphorylated in N2 compared to in N1 (p-JNK/total JNK, N1:0.14, N2:0.31). No significant difference was noted in status of extracellular-regulated kinase (ERK) and p38 kinase. Among Jun family proteins, levels of expression of JunB protein, but not c-Jun and JunD, decreased to 26% of those in N1 as judged by densitometric analysis. Three days incubation with JNK inhibitor, SP600125 (100μM) and NF- κB inhibitor, helenalin (1.0μM) inhibited cell growth of N2 to 25.4% and to51.2% of control culture, respectively. Furthermore, both of those inhibitors restored the levels of expression of JunB protein in N2 to 66% with 50μM SP600125and to 61% with 1.0μM helenalin, compared with those of N1. Increased expression of CD30 protein in N2 was not affected by the incubation with either of those inhibitors. Semi-quantitative RT-PCR analyses showed that growth inhibition by helenalin was accompanied with down-regulation of BCL2 mRNA(39.3±1.5% of control) in N2. Effect of SP600125 on BCL2 mRNA was negligible. In contrast, growth inhibition by SP600125 but not by helenalin resulted in up-regulation of CD86 mRNA(318±3% of control) in N2. Taken together, the present study showed that aberrantly activated JNK/AP-1 and NF- κB, at least in part, are responsible for disease progression in some types of CD30-positive ALCL, although details of signaling pathways triggered by altered CD30 in ALCL cells still remained to be elucidated. In addition, the data suggested that JunB, as a downstream molecule regulated by JNK and/or NF- κB, had a putative tumor suppressor function in CD30-positive lymphoma cells.

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L-amino acid oxidases: properties and molecular mechanisms of action

Biomeditsinskaya Khimiya ◽

10.18097/pbmc20125804372 ◽

2012 ◽

Vol 58 (4) ◽

pp. 372-384 ◽

Cited By ~ 7

Author(s):

E.V. Lukasheva ◽

A.A. Efremova ◽

E.M. Treshalina ◽

A.Ju. Arinbasarova ◽

A.G. Medentzev ◽

...

Keyword(s):

Amino Acid ◽

Molecular Mechanisms ◽

Biological Effects ◽

Essential Amino Acids ◽

Functional Roles ◽

Wide Range ◽

Previous Decade ◽

Lysine Degradation ◽

Mice Brain ◽

Apoptotic Pathways

During previous decade L-amino acid oxidases (LAAO) attracted the steady interest of researchers due to their poly functional effects on different biological systems. The review summarizes information concerning the sources, structure, phisico-chemical and catalytical properties of LAAO which exhibit antibacterial, antifungal, antiprotozoal, antiviral effects as well as the ambiguous action on platelet aggregation. Special attention is devoted to the elucidation of molecular mechanisms of LAAO action. It is proposed that the unique properties of LAAO are based on their catalytic reaction, which causes the decrease of L-amino acid levels, including the essential amino acids and formation of hydrogen peroxide. The action of liberated H2O2 on cells involves the synthesis of oxygen reactive species and the development of necrotic and apoptotic pathways of cell death. The presence of carbohydrate moieties in LAAO molecules promotes their attachment to cell's surface and creation of high H2O2 local concentrations. The wide range of LAAO biological effects is undoubtedly connected with their important functional roles in the organism. In particular, it was shown that in the mice brain the LAAO-catalyzed reaction is the single pathway of L-lysine degradation, while in the mice milk LAAO carry out the antibacterial effect and in human leucocytes LAAO take part in fulfilling their defending role. Protector action may be also attributed to the oxidases from the other numerous sources: microscopic fungi, snake venoms and sea inhabitants.

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Phosphorylation of Human Jak3 at Tyrosines 904 and 939 Positively Regulates Its Activity

Molecular and Cellular Biology ◽

10.1128/mcb.01789-07 ◽

2008 ◽

Vol 28 (7) ◽

pp. 2271-2282 ◽

Cited By ~ 19

Author(s):

Hanyin Cheng ◽

Jeremy A. Ross ◽

Jeffrey A. Frost ◽

Robert A. Kirken

Keyword(s):

Molecular Mechanisms ◽

Kinase Activity ◽

Interleukin 2 ◽

Intact Cells ◽

Positive Functional ◽

Functional Roles ◽

Disease States ◽

Proteomics Approach

ABSTRACT Janus tyrosine kinase 3 (Jak3) is essential for signaling by interleukin-2 (IL-2) family cytokines and proper immune function. Dysfunctional regulation of Jak3 may result in certain disease states. However, the molecular mechanisms governing Jak3 activation are not fully understood. In this study, we used a functional-proteomics approach to identify two novel tyrosine phosphorylation sites within Jak3, Y904 and Y939, which are conserved among Jak family proteins. By using phosphospecific antibodies, both residues were observed to be rapidly induced by stimulation of cells with IL-2 or other γc cytokines. Mechanistic studies indicated that Y904 and Y939 regulate Jak3 activities. A phenylalanine substitution at either site greatly reduced Jak3 kinase activity in vitro and its ability to phosphorylate signal transducer and activator of transcription 5 (Stat5) in vivo, suggesting that phosphorylation of these previously unrecognized residues positively regulates Jak3 activity. Y904 and Y939 were required for optimal ATP usage by Jak3, while phosphorylation of Y939 preferentially promoted Stat5 activity in intact cells. Together, these findings demonstrate positive functional roles for two novel Jak3 phosphoregulatory sites which may be similarly important for other Jak family members. Identification of these sites also provides new therapeutic opportunities to modulate Jak3 function.

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Molecular Mechanisms Underlying the Functions of Cellular Markers Associated with the Phenotype of Cancer Stem Cells

Current Stem Cell Research & Therapy ◽

10.2174/1574888x13666180821154752 ◽

2019 ◽

Vol 14 (5) ◽

pp. 405-420 ◽

Cited By ~ 2

Author(s):

Eduardo Alvarado-Ortiz ◽

Miguel Á. Sarabia-Sánchez ◽

Alejandro García-Carrancá

Keyword(s):

Stem Cells ◽

Cancer Stem Cells ◽

Molecular Mechanisms ◽

Tumor Biology ◽

Molecular Tools ◽

Recent Past ◽

Functional Roles ◽

Cellular Population ◽

Cellular Markers ◽

A Minor

Cancer Stem Cells (CSC) generally constitute a minor cellular population within tumors that exhibits some capacities of normal Stem Cells (SC). The existence of CSC, able to self-renew and differentiate, influences central aspects of tumor biology, in part because they can continue tumor growth, give rise to metastasis, and acquire drug and radioresistance, which open new avenues for therapeutics. It is well known that SC constantly interacts with their niche, which includes mesenchymal cells, extracellular ligands, and the Extra Cellular Matrix (ECM). These interactions regularly lead to homeostasis and maintenance of SC characteristics. However, the exact participation of each of these components for CSC maintenance is not clear, as they appear to be context- or cell-specific. In the recent past, surface cellular markers have been fundamental molecular tools for identifying CSC and distinguishing them from other tumor cells. Importantly, some of these cellular markers have been shown to possess functional roles that affect central aspects of CSC. Likewise, some of these markers can participate in regulating the interaction of CSC with their niche, particularly the ECM. We focused this review on the molecular mechanisms of surface cellular markers commonly employed to identify CSC, highlighting the signaling pathways and mechanisms involved in CSC-ECM interactions, through each of the cellular markers commonly used in the study of CSC, such as CD44, CD133, CD49f, CD24, CXCR4, and LGR5. Their presence does not necessarily implicate them in CSC biology.

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Galectin-3: A factotum in carcinogenesis bestowing an archery for prevention

Tumor Biology ◽

10.3233/tub-200051 ◽

2021 ◽

Vol 43 (1) ◽

pp. 77-96

Author(s):

T. Jeethy Ram ◽

Asha Lekshmi ◽

Thara Somanathan ◽

K. Sujathan

Keyword(s):

Cancer Progression ◽

Molecular Mechanisms ◽

Cancer Metastasis ◽

Epithelial Mesenchymal Transition ◽

Therapy Resistance ◽

Cellular Level ◽

Clinical Samples ◽

Innovative Strategy ◽

Mesenchymal Transition ◽

Galectin 3

Cancer metastasis and therapy resistance are the foremost hurdles in oncology at the moment. This review aims to pinpoint the functional aspects of a unique multifaceted glycosylated molecule in both intracellular and extracellular compartments of a cell namely galectin-3 along with its metastatic potential in different types of cancer. All materials reviewed here were collected through the search engines PubMed, Scopus, and Google scholar. Among the 15 galectins identified, the chimeric gal-3 plays an indispensable role in the differentiation, transformation, and multi-step process of tumor metastasis. It has been implicated in the molecular mechanisms that allow the cancer cells to survive in the intravascular milieu and promote tumor cell extravasation, ultimately leading to metastasis. Gal-3 has also been found to have a pivotal role in immune surveillance and pro-angiogenesis and several studies have pointed out the importance of gal-3 in establishing a resistant phenotype, particularly through the epithelial-mesenchymal transition process. Additionally, some recent findings suggest the use of gal-3 inhibitors in overcoming therapeutic resistance. All these reports suggest that the deregulation of these specific lectins at the cellular level could inhibit cancer progression and metastasis. A more systematic study of glycosylation in clinical samples along with the development of selective gal-3 antagonists inhibiting the activity of these molecules at the cellular level offers an innovative strategy for primary cancer prevention.

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Regulating the Regulators: Mechanisms of Substrate Selection of the O-GlcNAc Cycling Enzymes OGT and OGA

Glycobiology ◽

10.1093/glycob/cwab005 ◽

2021 ◽

Author(s):

Hannah M Stephen ◽

Trevor M Adams ◽

Lance Wells

Keyword(s):

Nutrient Sensing ◽

Substrate Selection ◽

Disease States ◽

Dynamic Modification ◽

Selection For ◽

Outstanding Question ◽

Glcnac Transferase ◽

Future Work ◽

Partner Proteins ◽

Selection Of

Abstract Thousands of nuclear and cytosolic proteins are modified with a single β-N-acetylglucosamine on serine and threonine residues in mammals, a modification termed O-GlcNAc. This modification is essential for normal development and plays important roles in virtually all intracellular processes. Additionally, O-GlcNAc is involved in many disease states, including cancer, diabetes, and X-linked intellectual disability. Given the myriad of functions of the O-GlcNAc modification, it is therefore somewhat surprising that O-GlcNAc cycling is mediated by only two enzymes: the O-GlcNAc transferase (OGT), which adds O-GlcNAc, and the O-GlcNAcase (OGA), which removes it. A significant outstanding question in the O-GlcNAc field is how do only two enzymes mediate such an abundant and dynamic modification. In this review, we explore the current understanding of mechanisms for substrate selection for the O-GlcNAc cycling enzymes. These mechanisms include direct substrate interaction with specific domains of OGT or OGA, selection of interactors via partner proteins, posttranslational modification of OGT or OGA, nutrient sensing, and localization alteration. Altogether, current research paints a picture of an exquisitely regulated and complex system by which OGT and OGA select substrates. We also make recommendations for future work, toward the goal of identifying interaction mechanisms for specific substrates that may be able to be exploited for various research and medical treatment goals.

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The Effect of Alcohol on Telomere Length: A Systematic Review of Epidemiological Evidence and a Pilot Study during Pregnancy

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18095038 ◽

2021 ◽

Vol 18 (9) ◽

pp. 5038

Author(s):

Andrea Maugeri ◽

Martina Barchitta ◽

Roberta Magnano San Lio ◽

Maria Clara La Rosa ◽

Claudia La Mastra ◽

...

Keyword(s):

Systematic Review ◽

Pilot Study ◽

Alcohol Consumption ◽

Telomere Length ◽

Molecular Mechanisms ◽

Epidemiological Studies ◽

Potential Association ◽

Significant Difference ◽

Periconceptional Period ◽

Using Data

Several studies—albeit with still inconclusive and limited findings—began to focus on the effect of drinking alcohol on telomere length (TL). Here, we present results from a systematic review of these epidemiological studies to investigate the potential association between alcohol consumption, alcohol-related disorders, and TL. The analysis of fourteen studies—selected from PubMed, Medline, and Web of Science databases—showed that people with alcohol-related disorders exhibited shorter TL, but also that alcohol consumption per se did not appear to affect TL in the absence of alcohol abuse or dependence. Our work also revealed a lack of studies in the periconceptional period, raising the need for evaluating this potential relationship during pregnancy. To fill this gap, we conducted a pilot study using data and samples form the Mamma & Bambino cohort. We compared five non-smoking but drinking women with ten non-smoking and non-drinking women, matched for maternal age, gestational age at recruitment, pregestational body mass index, and fetal sex. Interestingly, we detected a significant difference when analyzing relative TL of leukocyte DNA of cord blood samples from newborns. In particular, newborns from drinking women exhibited shorter relative TL than those born from non-drinking women (p = 0.024). Although these findings appeared promising, further research should be encouraged to test any dose–response relationship, to adjust for the effect of other exposures, and to understand the molecular mechanisms involved.

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Enantioenriched Positive Allosteric Modulators Display Distinct Pharmacology at the Dopamine D1 Receptor

Molecules ◽

10.3390/molecules26133799 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3799

Author(s):

Tim J. Fyfe ◽

Peter J. Scammells ◽

J. Robert Lane ◽

Ben Capuano

Keyword(s):

Dopamine D1 Receptor ◽

D1 Receptor ◽

Intrinsic Activity ◽

Optical Isomers ◽

Allosteric Modulators ◽

Disease States ◽

Starting Point ◽

Significant Difference ◽

Optically Pure ◽

Allosteric Properties

(1) Background: Two first-in-class racemic dopamine D1 receptor (D1R) positive allosteric modulator (PAM) chemotypes (1 and 2) were identified from a high-throughput screen. In particular, due to its selectivity for the D1R and reported lack of intrinsic activity, compound 2 shows promise as a starting point toward the development of small molecule allosteric modulators to ameliorate the cognitive deficits associated with some neuropsychiatric disease states; (2) Methods: Herein, we describe the enantioenrichment of optical isomers of 2 using chiral auxiliaries derived from (R)- and (S)-3-hydroxy-4,4-dimethyldihydrofuran-2(3H)-one (d- and l-pantolactone, respectively); (3) Results: We confirm both the racemate and enantiomers of 2 are active and selective for the D1R, but that the respective stereoisomers show a significant difference in their affinity and magnitude of positive allosteric cooperativity with dopamine; (4) Conclusions: These data warrant further investigation of asymmetric syntheses of optically pure analogues of 2 for the development of D1R PAMs with superior allosteric properties.

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Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Molecules ◽

10.3390/molecules26061676 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1676

Author(s):

Giulia Rossi ◽

Martina Placidi ◽

Chiara Castellini ◽

Francesco Rea ◽

Settimio D'Andrea ◽

...

Keyword(s):

In Vitro Model ◽

Molecular Mechanisms ◽

Biological Effects ◽

Cellular Damage ◽

X Rays ◽

Adolescent Cancer ◽

Radiation Induced ◽

Vitro Model ◽

Underlying Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

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YWHAZ interacts with DAAM1 to promote cell migration in breast cancer

Cell Death Discovery ◽

10.1038/s41420-021-00609-7 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Jie Mei ◽

Yan Liu ◽

Xinqian Yu ◽

Leiyu Hao ◽

Tao Ma ◽

...

Keyword(s):

Breast Cancer ◽

Poor Prognosis ◽

Molecular Mechanisms ◽

Transcriptional Regulator ◽

Expression Levels ◽

Functional Roles ◽

Normal Tissues ◽

Rhoa Activation ◽

Promote Cell Migration

AbstractDishevelled-associated activator of morphogenesis 1 (DAAM1) is a critical driver in facilitating metastasis in breast cancer (BrCa). However, molecular mechanisms for the regulation of DAAM1 activation are only partially elucidated. In this research, the expression levels of YWHAZ and DAAM1 were examined by immunohistochemistry (IHC) staining in BrCa tissues. The functional roles of tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ)–DAAM1 axis and their regulator microRNA-613 (miR-613) in BrCa cells and associated molecular mechanisms were demonstrated in vitro. As results, the expression levels of DAAM1 and YWHAZ were significantly upregulated in BrCa tissues compared with normal tissues and remarkably associated with poor prognosis. Besides, DAAM1 and YWHAZ were positively correlated with each other in BrCa tissues. YWHAZ interacted and colocalized with DAAM1 in BrCa cells, which was essential for DAAM1-mediated microfilament remodeling and RhoA activation. Moreover, miR-613 directly targeted both YWHAZ and DAAM1, contributing to inhibiting BrCa cells migration via blocking the complex of YWHAZ–DAAM1. To sum up, these data reveal that YWHAZ regulates DAAM1 activation, and the YWHAZ–DAAM1 complex is directly targeted by the shared post-transcriptional regulator miR-613.

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