Staphylococcus aureus is one of the most causative agents of mastitis and is associated with chronic udder infections. The persistency of the pathogen is believed to be the result of an insufficient triggering of local inflammatory signaling. In this study, the preclinical mastitis model was used, aiming to evaluate if lipopolysaccharide (LPS) or lipoteichoic acid (LTA) preconditioning could aid the host in more effectively clearing or at least limiting a subsequent S. aureus infection. A prototypic Gram-negative virulence factor, i.e., LPS and Gram-positive virulence factor, i.e., LTA were screened whether they were able to boost the local immune compartment. Compared to S. aureus-induced inflammation, both toxins had a remarkable high potency to efficiently induce two novel selected innate immunity biomarkers i.e., lipocalin 2 (LCN2) and chitinase 3-like 1 (CHI3L1). When combining mammary inoculation of LPS or LTA prior to a local S. aureus infection, we were able to modulate the innate immune response, reduce local bacterial loads, and induce either LCN2 or CHI3L1 at 24 h post-infection. Clodronate depletion of mammary macrophages also identified that macrophages contribute only to a limited extend to the LPS/LTA-induced immunomodulation upon S. aureus infection. Based on histological neutrophil influx evaluation, concomitant local cytokine profiles and LCN2/CHI3L1 patterns, the macrophage-independent signaling plays a major role in the LPS- or LTA-pretreated S. aureus-infected mouse mammary gland. Our results highlight the importance of a vigilant microenvironment during the innate immune response of the mammary gland and offer novel insights for new approaches concerning effective immunomodulation against a local bacterial infection.

Lipocalin 2 (LCN2) is an induced stressor that promotes the epithelial-mesenchymal transition (EMT). We previously demonstrated that the development of endometriosis in mice correlates with the secretion of LCN2 in the uterus. Here, we sought to clarify the relationship between LCN2 and EMT in endometrial epithelial cells and to determine whether LCN2 plays a role in endometriosis. Antibodies that functionally inhibit LCN2 slowed the growth of ectopic endometrial tissue in a mouse model of endometriosis, suggesting that LCN2 promotes the formation of endometriotic lesions. Using nutrient deprivation as a stressor, LCN2 expression was induced in cultured primary endometrial epithelial cells. As LCN2 levels increased, the cells transitioned from a round to a spindle-like morphology and dispersed. Immunochemical analyses revealed decreased levels of cytokeratin and increased levels of fibronectin in these endometrial cells, adhesive changes that correlate with induction of cell migration and invasion. Lcn2 knockdown also indicated that LCN2 promotes EMT and migration of endometrial epithelial cells. Our results suggest that stressful cellular microenvironments cause uterine tissues to secrete LCN2 and that this results in EMT of endometrial epithelial cells, which may correlate with the development of ectopic endometriosis. These findings shed light on the role of LCN2 in the pathology of endometrial disorders.

OBJECTIVE

In this study we aimed to investigate the relationship between lipocalin-2 (LCN2) levels and cardiovascular risk in patients with polycystic ovary syndrome (PCOS).

METHODS

Fifty patients with PCOS and 44 healthy women as controls were enrolled in the study. Laboratory and echocardiographic examinations were performed between the second and fifth days of the menstrual cycle. Serum LCN2 levels were measured with an enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

Serum LCN2 levels were significantly lower in PCOS patients (75.8 [51.4-131.2] ng/ml vs. 85.3 [56.7-138.5] ng/ml, p=0.038). Carotid intima-media thickness (CIMT) was increased in patients with PCOS compared to controls (0.61±0.13mm vs. 0.50±0.07mm, p=0.001). Aortic strain was lower in patients with PCOS. Aortic stiffness (β index) was significantly increased and distensibility was decreased in PCOS patients compared to control subjects. Serum LCN2 levels and the presence of PCOS were associated with CIMT in Spearman correlation analysis (p=0.05 and p<0.001) in all participants. There was no statistically significant relationship between LCN2 levels and CIMT in patients with PCOS (p=0.238).

CONCLUSIONS

In the present study, we found that LCN2 levels were low in women with PCOS. Although our patients with PCOS had elevated cardiac risk, there was no correlation between LCN2 levels and early findings of atherosclerosis.

Lipocalin-2 (LCN2) is a member of the lipocalin superfamily and plays a critical role in the regulation of various physiological processes, such as inflammation and obesity. In this study, we report that LCN2 negatively modulates the proliferation and differentiation of osteoclast precursors, resulting in impaired osteoclast formation. The overexpression of LCN2 in bone marrow-derived macrophages or the addition of recombinant LCN2 protein inhibits the formation of multinuclear osteoclasts. LCN2 suppresses macrophage colony-stimulating factor (M-CSF)-induced proliferation of osteoclast precursor cells without affecting their apoptotic cell death. Interestingly, LCN2 decreases the expression of the M-CSF receptor, c-Fms, and subsequently blocks its downstream signaling cascades. In addition, LCN2 inhibits RANKL-induced osteoclast differentiation and attenuates the expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1), which are important modulators in osteoclastogenesis. Mechanistically, LCN2 inhibits NF-κB signaling pathways, as demonstrated by the suppression of IκBα phosphorylation, nuclear translocation of p65, and NF-κB transcriptional activity. Thus, LCN2 is an anti-osteoclastogenic molecule that exerts its effects by retarding the proliferation and differentiation of osteoclast lineage cells.

Lipocalin (LCN) family members are small secreted proteins that bind to small hydrophobic molecules via their characteristic central β-barrels. A couple of LCN family members, including major urinary protein 1, retinol-binding protein 4, LCN2, and LCN13, have been reported to regulate insulin sensitivity and nutrient metabolism. LCN13 is expressed by multiple tissues, including the liver, pancreas, epididymis, and skeletal muscle, and is secreted into the bloodstream in mice. Obesity is associated with a downregulation of LCN13 expression and lower levels of circulating LCN13. LCN13 therapies overcome LCN13 deficiency in mice with either genetic or dietary obesity, leading to an improvement in hyperglycemia, hyperinsulinemia, insulin resistance, glucose intolerance, and hepatic steatosis. In hepatocytes, LCN13 directly suppresses hepatic gluconeogenesis and lipogenesis but increases fatty acid β oxidation. LCN13 also enhances insulin sensitivity in adipocytes. The potential mechanisms of the antidiabetes and antisteatosis actions of LCN13 are discussed.

UNASSIGNED

Alport syndrome (AS) is a hereditary, progressive nephritis caused by mutation of type IV collagen. Previous studies have shown that activation of signal transducer and activator of transcription 3 (STAT3) exacerbates other renal diseases, but whether STAT3 activation exacerbates AS pathology is still unknown. Here we aim to investigate the involvement of STAT3 in the progression of AS.

UNASSIGNED

Phosphorylated STAT3 expression was assessed by immunoblotting analysis of kidneys and glomeruli of an AS mouse model (Col4a5 G5X mutant). To determine the effect of blocking STAT3 signaling, we treated AS mice with the STAT3 inhibitor stattic (10 mg/kg i.p., three times per week for 10 weeks; n = 10). We assessed the renal function [proteinuria, blood urea nitrogen (BUN), serum creatinine] and analyzed the glomerular injury score, fibrosis and inflammatory cell invasion by histological staining. Moreover, we analyzed the gene expression of nephritis-associated molecules.

UNASSIGNED

Phosphorylated STAT3 was upregulated in AS kidneys and glomeruli. Treatment with stattic ameliorated the progressive renal dysfunction, such as increased levels of proteinuria, BUN and serum creatinine. Stattic also significantly suppressed the gene expression levels of renal injury markers (Lcn2, Kim-1), pro-inflammatory cytokines (Il-6, KC), pro-fibrotic genes (Tgf-β, Col1a1, α-Sma) and Mmp9. Stattic treatment decreased the renal fibrosis congruently with the decrease of transforming growth factor beta (TGF-β) protein and increase of antifibrosis-associated markers p-Smad1, 5 and 8, which are negative regulators of TGF-β signaling.

UNASSIGNED

STAT3 inhibition significantly ameliorated the renal dysfunction in AS mice. Our finding identifies STAT3 as an important regulator in AS progression and provides a promising therapeutic target for AS.

Lipocalin-2 (LCN2) is a member of the lipocalin family whose expression is modulated in several conditions, including cell differentiation, innate immunity, stress, and cancer. Although it is known that it is expressed in bone, its function in this tissue remains poorly studied. To this end, we took advantage of transgenic mice lines that expressed LCN2 driven by a bone specific type I collagen (LCN2-Tg). In the bone marrow (BM) of LCN2-Tg mice we observed an increased number of phenotypically long-term hematopoietic stem cells (LT-HSC) that also displayed a higher proliferation rate compared to wild-type controls (Wt). Furthermore, hematopoietic progenitor cells, obtained from LCN2-Tg BM showed an increased clonogenic capacity compared to those obtained from LCN2-Tg spleen, a higher concentration of serum erythropoietin and a higher number of mature erythrocytes in the peripheral blood of old LCN2-Tg animals compared to aged-matched wt. The findings of a combined increase in the BM of the LCN2-Tg mice of SDF-1, SCF, and TIMP-1 levels along with the reduction of both MMP-9 activity and cathepsin K concentration may explain the observed effects on the HSC compartment. This study shows that LCN2 overexpression in bones modifies the BM microenvironment via modulation of the expression of key secreted factors and cytokines, which in turn regulate the HSC niche behavior enhancing both HSC homing in young mice and erythrocytes production in older mice.

Lipocalin-2 (LCN2) has been previously characterized as an adipokine regulating thermogenic activation of brown adipose tissue and retinoic acid (RA)-induced thermogenesis in mice. The objective of this study was to explore the role and mechanism for LCN2 in the recruitment and retinoic acid-induced activation of brown-like or ‘beige’ adipocytes. We found LCN2 deficiency reduces key markers of thermogenesis including uncoupling protein-1 (UCP1) and peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) in inguinal white adipose tissue (iWAT) and inguinal adipocytes derived from Lcn2 −/− mice. Lcn2 −/− inguinal adipocytes have attenuated insulin-induced upregulation of thermogenic gene expression and p38 mitogen-activated protein kinase (p38MAPK) signaling pathway activation. This is accompanied by a lower basal and maximal oxidative capacity in Lcn2 −/− inguinal adipocytes, indicating mitochondrial dysfunction. Recombinant Lcn2 was able to restore insulin-induced p38MAPK phosphorylation in both WT and Lcn2 −/− inguinal adipocytes. Rosiglitazone treatment during differentiation of Lcn2 −/− adipocytes is able to recruit beige adipocytes at a normal level, however, further activation of beige adipocytes by insulin and RA is impaired in the absence of LCN2. Further, the synergistic effect of insulin and RA on UCP1 and PGC-1α expression is markedly reduced in Lcn2 −/− inguinal adipocytes. Most intriguingly, LCN2 and the retinoic acid receptor-alpha (RAR-α) are concurrently translocated to the plasma membrane of adipocytes in response to insulin, and this insulin-induced RAR-α translocation is absent in adipocytes deficient in LCN2. Our data suggest a novel LCN2-mediated pathway by which RA and insulin synergistically regulates activation of beige adipocytes via a non-genomic pathway of RA action.

Lipocalin-2 is not only a sensitive biomarker, but it also contributes to the pathogenesis of renal injuries. The present study demonstrates that adipose tissue-derived lipocalin-2 plays a critical role in causing both chronic and acute renal injuries. Four-week treatment with aldosterone and high salt after uninephrectomy (ANS) significantly increased both circulating and urinary lipocalin-2, and it induced glomerular and tubular injuries in kidneys of WT mice. Despite increased renal expression of lcn2 and urinary excretion of lipocalin-2, mice with selective deletion of lcn2 alleles in adipose tissue (Adipo-LKO) are protected from ANS- or aldosterone-induced renal injuries. By contrast, selective deletion of lcn2 alleles in kidney did not prevent aldosterone- or ANS-induced renal injuries. Transplantation of fat pads from WT donors increased the sensitivity of mice with complete deletion of Lcn2 alleles (LKO) to aldosterone-induced renal injuries. Aldosterone promoted the urinary excretion of a human lipocalin-2 variant, R81E, in turn causing renal injuries in LKO mice. Chronic treatment with R81E triggered significant renal injuries in LKO, resembling those observed in WT mice following ANS challenge. Taken in conjunction, the present results demonstrate that lipocalin-2 derived from adipose tissue causes acute and chronic renal injuries, largely independent of local lcn2 expression in kidney.

OBJECTIVE

Lipocalin-2 (Lcn2), a newer adipocyte-secreted acute phase protein, was recently reported to be correlated with potential effects on obesity and inflammation. The reaction of this protein to progressive exercise has not been evaluated yet. This study was designed to compare the serum Lcn2 and high-sensitivity C-reactive protein (hs-CRP) levels after participating in an acute bout of treadmill protocol in obese and normal-weight men.

METHODS

NINE OBESE (AGED: 43.2±4.6 yrs and body mass index (BMI): 31.4±1.6 kg/m(2)) and 9 normal-weight (aged: 42.9±4.4 yrs and BMI: 23.03±1.7 kg/m(2); mean ± SD) sedentary men selected randomly from volunteers performed a single bout of exercise according to the treadmill Bruce protocol.

RESULTS

Before the exercise, Lcn2 level was higher in obese than normal-weight individuals (P<0.05). A significant increase in Lcn2, hs-CRP, white blood cells (WBC) and insulin resistance index was observed after the exercise in both groups (P<0.05). The level of Lcn2, hs-CRP and WBC increase was more significant in obese individuals than normal-weight subjects after the exercise (P<0.05).

CONCLUSIONS

It seems that the levels of Lcn2 and other inflammatory markers elevated in obese and normal-weight men after participating in an exhaustive progressive exercise. These changes in obese men were considerable.

Aspirin is the most widely used antiplatelet agent because it is safe, efficient, and inexpensive. However, a significant subset of patients does not exhibit a full inhibition of platelet aggregation, termed 'aspirin resistance' (AR). Several major studies have observed that AR patients have a 4-fold increased risk of myocardial infarction (MI), stroke, and other thrombotic events. Arachidonic acid-stimulated whole blood aggregation was tested in 132 adults at risk for ischemic events, and identified an inadequate response to aspirin therapy in 9 patients (6.8%). Expression profiling of blood RNA by microarray was used to generate new hypotheses about the etiology of AR. Among the differentially expressed genes, there were decreases in several known platelet transcripts, including clusterin (CLU), glycoproteins IIb/IIIa (ITGA2B/3), lipocalin (LCN2), lactoferrin (LTF), and the thrombopoetin receptor (MPL), but with increased mRNA for the T-cell Th1 chemokine CXCL10. There was a strong association of AR with expression of HLA-DRB4 and HLA-DQA1. Similar HLA changes have been linked to autoimmune disorders, particularly antiphospholipid syndrome (APS), in which autoantibodies to phospholipid/protein complexes can trigger platelet activation. Consistent with APS, AR patients exhibited a 30% reduction in platelet counts. Follow-up testing for autoimmune antibodies observed only borderline titers in AR patients. Overall, these results suggest that AR may be related to changes in platelet gene expression creating a hyperreactive platelet, despite antiplatelet therapy. Future studies will focus on determining the protein levels of these differential transcripts in platelets, and the possible involvement of HLA restriction as a contributing factor.

Lipocalin-2 (LCN2) is an acute-phase protein induced by injury, infection, or other inflammatory stimuli. LCN2 binds small hydrophobic ligands and interacts with cell surface receptor to regulate diverse cellular processes. The role of LCN2 as a chemokine inducer in the central nervous system (CNS) has been previously reported. Based on the previous participation of LCN2 in neuroinflammation, we investigated the role of LCN2 in formalin-induced nociception and pathological pain. Formalin-induced nociceptive behaviors (licking/biting) and spinal microglial activation were significantly reduced in the second or late phase of the formalin test in Lcn2 knockout mice. Likewise, antibody-mediated neutralization of spinal LCN2 attenuated the mechanical hypersensitivity induced by peripheral nerve injury in mice. Taken together, our results suggest that LCN2 can be therapeutically targeted, presumably for both prevention and reversal of acute inflammatory pain as well as pathological pain.

The iron siderophore binding protein lipocalin 2 (LCN2, also known as 24p3, NGAL and siderocalin) may be involved in iron homeostasis, but to date, little is known about expression of its putative receptor, brain-type organic cation transporter (BOCT, also known as BOCT1, 24p3R, NGALR and LCN2R), in the brain during neurodegeneration. The present study was carried out to elucidate the expression of LCN2 and BOCT in hippocampus after excitotoxicity induced by the glutamate analog, kainate (KA) and a possible role of LCN2 in neuronal injury. As reported previously, a rapid and sustained induction in expression of LCN2 was found in the hippocampus after intracerebroventicular injection of KA. BOCT was expressed in neurons of the saline-injected control hippocampus, and immunolabel for BOCT protein was preserved in pyramidal neurons of CA1 at 1 day post-KA injection, likely due to the delayed onset of neurodegeneration after KA injection. At 3 days and 2 weeks after KA injections, loss of immunolabel was observed due to degenerated neurons, although remaining neurons continued to express BOCT, and induction of BOCT was found in OX-42 positive microglia. This resulted in an overall decrease in BOCT mRNA and protein expression after KA treatment. Increased expression of the pro-apoptotic marker, Bim, was found in both neurons and microglia after KA injection, but TUNEL staining indicating apoptosis was found primarily in Bim-expressing neurons, but not microglia. Interaction between LCN2 and BOCT was found by DuoLink assay in cultured hippocampal neurons. Apo-LCN2 without iron caused no significant differences in neuronal Bim expression or cell survival, whereas holo-LCN2 consisting of LCN2:iron:enterochelin complex increased Bim mRNA expression and decreased neuronal survival. Together, results suggest that LCN2 and BOCT may have a role in neuronal injury.

We hypothesized that evolution of salivary gland secretory proteome has been important in adaptation to insectivory, the most common dietary strategy among Chiroptera. A submandibular salivary gland (SMG) transcriptome was sequenced for the little brown bat, Myotis lucifugus. The likely secretory proteome of 23 genes included seven (RETNLB, PSAP, CLU, APOE, LCN2, C3, CEL) related to M. lucifugus insectivorous diet and metabolism. Six of the secretory proteins probably are endocrine, whereas one (CEL) most likely is exocrine. The encoded proteins are associated with lipid hydrolysis, regulation of lipid metabolism, lipid transport, and insulin resistance. They are capable of processing exogenous lipids for flight metabolism while foraging. Salivary carboxyl ester lipase (CEL) is thought to hydrolyze insect lipophorins, which probably are absorbed across the gastric mucosa during feeding. The other six proteins are predicted either to maintain these lipids at high blood concentrations or to facilitate transport and uptake by flight muscles. Expression of these seven genes and coordinated secretion from a single organ is novel to this insectivorous bat, and apparently has evolved through instances of gene duplication, gene recruitment, and nucleotide selection. Four of the recruited genes are single-copy in the Myotis genome, whereas three have undergone duplication(s) with two of these genes exhibiting evolutionary 'bursts' of duplication resulting in multiple paralogs. Evidence for episodic directional selection was found for six of seven genes, reinforcing the conclusion that the recruited genes have important roles in adaptation to insectivory and the metabolic demands of flight. Intragenic frequencies of mobile- element-like sequences differed from frequencies in the whole M. lucifugus genome. Differences among recruited genes imply separate evolutionary trajectories and that adaptation was not a single, coordinated event.

Amyloid beta (Aβ) peptides, in particular Aβ42 and Aβ40, exert neurotoxic effects and their overproduction leads to amyloid deposits in the brain, thus constituting an important biomolecular target for treatments of Alzheimer's disease (AD). We describe the engineering of cognate Anticalins as a novel type of neutralizing protein reagent based on the human lipocalin scaffold. Phage display selection from a genetic random library comprising variants of the human lipocalin 2 (Lcn2) with mutations targeted at 20 exposed amino acid positions in the four loops that form the natural binding site was performed using both recombinant and synthetic target peptides and resulted in three different Anticalins. Biochemical characterization of the purified proteins produced by periplasmic secretion in Escherichia coli revealed high folding stability in a monomeric state, with Tm values ranging from 53.4°C to 74.5°C, as well as high affinities for Aβ40, between 95 pM and 563 pM, as measured by real-time surface plasmon resonance analysis. The central linear VFFAED epitope within the Aβ sequence was mapped using a synthetic peptide array on membranes and was shared by all three Anticalins, despite up to 13 mutual amino acid differences in their binding sites. All Anticalins had the ability-with varying extent-to inhibit Aβ aggregation in vitro according to the thioflavin-T fluorescence assay and, furthermore, they abolished Aβ42-mediated toxicity in neuronal cell culture. Thus, these Anticalins provide not only useful protein reagents to study the molecular pathology of AD but they also show potential as alternative drug candidates compared with antibodies.

OBJECTIVE

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) insufficiency is commonly found in breast cancer patients with metastasis. We investigated the mechanisms by which PTEN affects breast cancer metastatic behavior.

METHODS

Migration and invasion assay, western blot, immunofluorescent staining and zebrafish animal model were applied.

RESULTS

We showed that PTEN insufficiency induced an increase in MCF-7 cell migration and invasion through induction of epithelial-mesenchymal transition (EMT), which was triggered by up-regulation of the EMT-inducing transcriptional factors Zeb1, Zeb2, Snail, Slug and Twist. Simultaneously, E-cadherin expression was inhibited and P-cadherin was up-regulated. Further, WNT1 inducible signaling pathway protein 1 (WISP1) and lipocalin-2 (LCN2) expressions were increased after PTEN knockdown in MCF-7 cells, which also exhibited increased filamentous actin (F-actin) synthesis and extracellular matrix metalloproteinase-2 (MMP-2) and MMP-9 expression. We further showed that PTEN knockdown in MCF-7 cells could increase cell migration in the xenograft zebrafish model.

CONCLUSIONS

Our findings reveal new therapeutic targets for breast cancer patients with PTEN insufficiency.

Hepatic fibrosis is characterized by excessive accumulation of extracellular matrix. Matrix metalloproteinases (MMPs) play an important role in the remodeling of the extracellular matrix during hepatic fibrosis. Lipocalin-2 (LCN2) forms complexes with MMP-9 and can be detected in the urine of patients with several types of cancers. The objective of this study was to examine the relationship between urinary LCN2 levels and MMP-9 activity with respect to the stage of liver fibrosis in patients with chronic hepatitis C (CHC), and to assess the utility of urine LCN2 as a non-invasive marker of hepatic fibrosis. Fresh spot urine samples were prospectively collected from forty-two interferon-naive CHC patients who underwent liver biopsy. The stage of hepatic fibrosis was assessed according to the METAVIR fibrosis score; 18 patients had no or mild fibrosis (stages F0 and F1) and 24 patients showed significant fibrosis (stages F2-F4). Immunoblot analyses demonstrated co-migration of urine LCN2 and MMP-9. Gelatin zymography showed that urinary MMP-9/MMP-2 activity ratios were higher in patients with significant fibrosis (F2-F4) than in patients no or mild fibrosis (F0-F1). Urine LCN2 levels which were normalized to urine creatinine concentration (urine LCN2-to-creatinine ratio; ULCR) were higher in F2-F4 patients compared to F0-F1 patients. There was a positive correlation between ULCR and urine MMP-9/MMP-2 activity ratios (r = 0.735). ULCR and AST-to-platelet ratio index were independent predictors of significant fibrosis by multivariate analysis. The present study suggests that urinary LCN2 is a novel marker of hepatic fibrosis by reflecting urine MMP-9 activity in CHC.

Periodontitis is an infectious inflammatory disease that destroys the tooth-supporting (periodontal) tissues. Porphyromonas gingivalis is an oral pathogen highly implicated in the pathogenesis of this disease. It can exert its effects to a number of cells, including osteogenic bone marrow stromal cells which are important for homeostastic capacity of the tissues. By employing gene microarray technology, this study aimed to describe the overall transcriptional events (>2-fold regulation) elicited by P. gingivalis secreted products in bone marrow stromal cells, and to dissect further the categories of genes involved in bone metabolism, inflammatory and immune responses. After 6 h of challenge with P. gingivalis, 271 genes were up-regulated whereas 209 genes were down-regulated, whereas after 24 h, these numbers were 259 and 109, respectively. The early (6 h) response was characterised by regulation of genes associated with inhibition of cell cycle, induction of apoptosis and loss of structural integrity, whereas the late (24 h) response was characterised by induction of chemokines, cytokines and their associated intracellular pathways (such as NF-κB), mediators of connective tissue and bone destruction, and suppression of regulators of osteogenic differentiation. The most strongly up-regulated genes were lipocalin 2 (LCN2) and serum amyloid A3 (SAA3), both encoding for proteins of the acute phase inflammatory response. Collectively, these transcriptional changes elicited by P. gingivalis denote that the fundamental cellular functions are hindered, and that the cells acquire a phenotype commensurate with propagated innate immune response and inflammatory-mediated tissue destruction. In conclusion, the global transcriptional profile of bone marrow stromal cells in response to P. gingivalis is marked by deregulated homeostatic functions, with implications in the pathogenesis of periodontitis.

BACKGROUND

Despite optimal primary treatment of ovarian cancer, overall prognosis is poor due to recurrences. While steroid hormone receptors are frequently expressed, the role of estrogen receptor (ER) in ovarian carcinogenesis, response to treatment or prognosis has not been established. We analyzed the gene-expression in response to estradiol (E2) and genistein (Gen) in ovarian cancer cells.

METHODS

Cell lines (Br-1, UL-1; Oy-1), treated with E2 (10 nM) or Gen (5 microM), were used for gene expression profiling. RT-PCR and Western immunoblotting were used to further analyze gene expression data.

RESULTS

Twenty-four genes were differentially regulated in ovarian cancer cell lines. C3, CLU, COL6A1, DLC1, NME1, NRIP1, PTEN, RAC2, S100A2 were down-regulated with E2 in Br-1 and UL-1 cells. MK167, SERPINB5, SLC7A5, CDK1NA, LCN2, PLAU, PHB2, CTSB, EGLN2, ERBB2, HMGB1, ID2, ITGB4, TOP2A were up-regulated in Oy-1 cells with E2 and/or genistein. ERBB2 and ID2 (E2 and Gen), LCN2, PHB2 and HMGB1 (Gen) were down-regulated in Br-1 cells. ERalpha and ERbeta were detected in all cell lines at different levels.

CONCLUSIONS

Variable response of ovarian cancer cells to E2 and Gen was observed. Study of ERs including splice variants, co-regulatory molecules are necessary to understand the relevance of receptors.

Our objective was to assess whether neutrophil gelatinase-associated lipocalin (NGAL)/lipocalin 2 (LCN2) expression in cervical human papillomavirus (HPV) lesions has implications on the outcome of HPV infections or disease progression. Cervical biopsy specimens from 225 women in the Latin American Screening study were analyzed for NGAL/LCN2 expression using immunohistochemical analysis, to assess associations with cervical intraepithelial neoplasia (CIN) grade, high-risk HPV, and in predicting outcomes of high-risk (HR)-HPV infections. Expression of NGAL/LCN2 increased with lesion grade (odds ratio [OR], 3.86; 95% confidence interval [CI], 1.53-9.71; P = .001). Up-regulation was also related to HR-HPV detection (OR, 2.21; 95% CI, 1.15-4.24; P = .016) and showed a linear relationship to HR-HPV load (P = .002). NGAL/LCN2 expression was of no value in predicting the outcomes of HR-HPV infections or the surrogate end points (incident CIN 1+ and CIN 2+) of progressive disease. Because the SV40 large T antigen is a powerful up-regulator of this lipocalin, up-regulation of NGAL/LCN2 in CIN is probably induced by HR-HPV E6 oncoprotein, most likely by eliminating its normal transcription repression exerted by wild-type p53.

Esophageal cancer is the eighth most common cancer and the sixth most common cause of cancer-related deaths worldwide. Despite the research progress in understanding the disease, the mechanism underlying the metastasis is still unclear. Here, we successfully generated a highly metastatic cell subline, designated as KYSE150-LuM, derived from an esophageal squamous cell carcinoma cell line (KYSE150) by in vivo selection. To elucidate the mechanisms driving metastasis, we characterized the gene expression differences between LuM cells and parent KYSE150 cells. IL-6, IL-1β, and LCN2, previously associated with tumor growth and metastasis, were up-regulated in LuM cells. Recent studies on cancer have increasingly focused on the tumor microenvironment, from which these cytokines are released. The fact that these three cytokines (IL-6, IL-1β, LCN2) were up-regulated in LuM cells indicates that these highly metastatic cells obtained through in vivo selection will be a useful resource for further studies on elucidating the mechanisms underlying the tumor microenvironment which is associated with cytokine-related tumor growth and metastasis. Moreover, LuM cells could disseminate to the lung in shorter period of time in vivo, indicating their utility for in vivo experiments of metastasis and new therapeutic targets in a shorter period of time than currently possible.

Recent studies have investigated the roles of FXR deficiency in the pathogenesis of alcoholic liver disease (ALD). However, the underlying molecular mechanisms remain unclear. In this study, FXR knockout (FXR^-/-) and wild-type (WT) mice were subjected to chronic-plus-binge alcohol feeding to study the effect of FXR deficiency on ALD development. The degree of liver injury was greater in FXR^-/- mice compared to WT mice. Ethanol feeding enhanced hepatic steatosis in FXR^-/- mice, accompanied by decreased mRNA levels of Pparα and Srebp-1c. The expression of Lcn2 was increased by ethanol treatment, despite unchanged expression of pro-inflammatory cytokines Tnfα, Il6 and Il-1β. Furthermore, ethanol treatment altered bile acid (BA) homeostasis to a greater extent in FXR^-/- mice, as well as serum and hepatic BA pool composition. The mRNA levels of hepatic Cyp7a1 and Shp, as well as intestinal Fgf15, were decreased in WT mice with ethanol feeding, which were further reduced in FXR^-/- mice. Levels of both primary and secondary BAs were markedly elevated in FXR^-/- mice, which were further increased after ethanol treatment. Moreover, hepatic MAPK signaling pathways were disturbed presumably by increased hepatic BA levels. In summary, FXR deficiency increased hepatic steatosis and altered BA pool composition, contributing to worsened liver toxicity.

BACKGROUND

De-regulation of adipocytokines synthesis and secretion appears to be involved in the pathogenesis of different metabolic diseases.

OBJECTIVE

We assessed a possible association between plasmatic levels of lipocalin-2 (LCN2) and type 2 diabetes mellitus (T2DM), as well as among levels of LCN2 and those of adiponectin, ghrelin, leptin and resistin, in Mexican diabetic patients.

METHODS

Fifty-three healthy individuals and fifty-three with long-term T2DM were included. Measurements from all patients for BMI, fasting glucose, insulin, lipids and adipocytokine profiles were obtained.

RESULTS

Comparison of data between the corresponding for diabetic subjects and those of healthy individuals showed significant differences in every anthropometric and metabolic parameter analyzed (P < 0.001). In diabetic subjects, lipocalin-2 and ghrelin plasmatic levels were statistically diminished (P < 0.001) in comparison with the levels registered in healthy subjects. In conclusion, in this study we found that LCN2 plasmatic levels are reduced in Mexican subjects with long-term diabetes and this reduction in circulating concentrations is similar to the one reported for anti-inflammatory adipocytokines, which suggests that lipocalin-2 is somehow involved in insulin resistance and cardiometabolic alterations through an uncharacterized mechanism generated by the inflammation process.

Lipocalin-2 (LCN2) is a member of the lipocalin family, small secreted proteins functioning as modulators of many different physiological processes including cell differentiation, proliferation and apoptosis. LCN2 expression is also up-regulated in several pathological conditions, including inflammation and cancer. LCN2 synthesis has been described in epithelia, bone and cells of the immune system. Despite its wide expression the role of LCN2 remains to be fully elucidated. To better understand the role of this lipocalin in the bone/bone marrow system we generated transgenic mice over-expressing LCN2 specifically in bone under the control of a type I collagen promoter. In the bone marrow of these transgenic mice we observed an increased expression of SDF-1 that correlated with an increased number of CD34+/CXCR4+ (SDF-1 receptor) cells. To some extent, this appeared due to an enhanced cell proliferation rate. The higher level of the factor synthesis and the increased number of cells expressing its receptor was maintained during animal aging. Our results show that LCN2 could play a role in determining the number of CD34+/CXCR4+ precursor cells in the bone marrow thus contributing to the control of the bone marrow microenvironment.