• Reproductive and Developmental Biology
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• v.33 no.2
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• pp.71-76
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• 2009

Salivary lipocalin (SAL1) is a member of the lipocalin protein family that has a property to associate with many lipophilic molecules. The importance of SAL1 during pregnancy in pigs has been suggested by our previous study which has shown that SAL1 is expressed in the uterine endometrium in a cell type- and implantation stage-specific manner and secreted into the uterine lumen. However, function of SAL1 in the uterus during pregnancy in pigs is not known. To understand SAL1 function in the uterus during pregnancy, we generated recombinant porcine SAL1 protein in an insect cell line. Porcine SAL1 cDNA was cloned into a baculovirus expression vector using RT-PCR and total RNA from uterine endometrium on day 12 of pregnancy, and the expression vector was used to generate recombinant Bacmid containing the SAL1 gene. The recombinant Bacmid was then transfected Sf9 cell to produce recombinant baculovirus. By infecting Sf9 cell with recombinant baculovirus, we established a SAL1-expressing insect cell expression system. Immunoblot analysis confirmed SAL1 expression in the infected cells. Recombinant SAL1 produced by the Sf9 cell line will be useful for understanding physiological function of SAL1 during pregnancy in pigs.

• Clinical and Experimental Pediatrics
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• v.64 no.7
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• pp.347-354
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• 2021

Background: Neutrophil gelatinase-associated lipocalin (NGAL) has emerged as a valuable biomarker of urinary tract infection (UTI) in children. Purpose: This study aimed to compare the diagnostic accuracy of urinary NGAL (uNGAL) with those of serum C-reactive protein (CRP) and white blood cell (WBC) count for predicting UTI and acute pyelonephritis (APN) in febrile children. Methods: The medical charts of children undergoing uNGAL measurements between November 2017 and August 2019 were retrospectively reviewed. Patients with a suspected or diagnosed UTIs were included. The diagnostic accuracies of uNGAL, serum CRP, and WBC count for detecting UTI and APN were investigated. Independent predictors of UTI and APN were investigated using multivariable logistic regression analyses. Results: A total of 321 children were enrolled in this study. The uNGAL levels were higher in the UTI group (n=157) than in the non-UTI group (n=164) (P<0.05). Among children with a UTI, uNGAL levels were higher in the APN group (n=70) than, the non-APN group (n=87) (P<0.05). In the multivariate analysis, uNGAL was independently associated with UTI and APN (both P<0.05). Serum CRP and WBC count were not correlated with the presence of UTI and APN. Receiver operating curve analyses showed that the uNGAL level had the highest area under the curve (AUC) for predicting UTI and APN, respectively (AUC, uNGAL vs. CRP vs. WBC count, 0.860 vs. 0.608 vs. 0.669 for UTI; 0.780 vs. 0.680 vs. 0.639 for APN, all P<0.05, respectively). The predictive values and likelihood ratios of uNGAL were superior to those of serum CRP and WBC count for detecting UTI and APN at each cutoff level. Conclusion: UNGAL may be more useful than serum CRP and WBC count for identifying and assessing UTI in febrile children.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.335-344
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• 2019

Obesity causes inflammation and impairs thermogenic functions in brown adipose tissue (BAT). The adipokine lipocalin 2 (LCN2) has been implicated in inflammation and obesity. Herein, we investigated the protective effects of caloric restriction (CR) on LCN2-mediated inflammation and oxidative stress in the BAT of high-fat diet (HFD)-fed mice. Mice were fed a HFD for 20 weeks and then either continued on the HFD or subjected to CR for the next 12 weeks. CR led to the browning of the white fat-like phenotype in HFD-fed mice. Increased expressions of LCN2 and its receptor in the BAT of HFD-fed mice were significantly attenuated by CR. Additionally, HFD+CR-fed mice had fewer neutrophils and macrophages expressing LCN2 and iron-positive cells than HFD-fed mice. Further, oxidative stress and mitochondrial fission induced by a HFD were also significantly attenuated by CR. Our findings indicate that the protective effects of CR on inflammation and oxidative stress in the BAT of obese mice may be associated with regulation of LCN2.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.49-53
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• 2016

Acute kidney injury (AKI) is a common syndrome resulting in kidney damage and malfunction within a few days or even a few hours. The diagnosis of AKI depends on routine biochemical tests, including serum creatinine, aspartate aminotransferase (AST), alanine aminotransaminase (ALT), blood urea nitrogen (BUN), and electrolytes. Plasma neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker that shows correlation with the severity of acute infections and kidney injuries. The predictive value in other conventional assays for kidney functions has been reported to cause distraction for AKI syndrome. The aim of this study is to verify the predictive value of plasma NGAL in patients with established AKI. The NGAL kit for checkup demonstrates sensitivity of ${\geq}300$ (92.2%), ${\geq}200$ (95.6%), ${\geq}100$ (99.6%), specificity of ${\geq}300$ (95.1%), ${\geq}200$ (97.3%), ${\geq}100$ (99.4%), positive predictability of ${\geq}300$ (93.3%), ${\geq}200$ (93.4%), ${\geq}100$ (99.2%), and negative predictability of ${\geq}300$ (96.7%), ${\geq}200$ (97.7%), ${\geq}100$ (98.1%), respectively. The plasma NGAL compared with the enzyme-linked immunosorbent assay (ELISA) has been shown to be an early predictive biomarker of AKI. The NGAL kit, recently developed for point-of-care of plasma specimens, is thought to be a useful and reliable biomarker for the early diagnosis of decreased kidney functions.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4965-4969
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• 2015

LCN2 (Lipocalin 2) is a 25 KD secreted acute phase protein, reported to be a novel regulator of angiogenesis in breast cancer. Up regulation of LCN2 had been observed in multiple cancers including breast cancer, pancreatic cancer and ovarian cancer. However, the role of LCN2 promoter methylation in the formation of microvessels is poorly understood. The aim of this study was to analyze the association of LCN 2 promoter methylation with microvessel formation and tumor cell proliferation in breast cancer patients. The LCN2 promoter methylation status was studied in 64 breast cancer tumors by methylation specific PCR (MSP). Evaluation of microvessel density (MVD) and Ki67 cell proliferation index was achieved by immunohistochemical staining using CD34 and MIB-1 antibodies, respectively. LCN2 promoter unmethylation status was observed in 43 (67.2%) of breast cancer patients whereas LCN2 methylation status was seen in 21 (32.8%). Further, LCN2 promoter unmethylation status was associated with aggressive tumor phenotype and elevated mean MVD in breast cancer patients.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.342-347
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• 2011

Background: Glial cells are involved in immune and inflammatory responses in the central nervous system (CNS). Glial cells such as microglia and astrocytes also provide structural and functional support for neurons. Migration and morphological changes of CNS cells are associated with their physiological as well as pathological functions. The secreted protein lipocalin-2 (LCN2) has been previously implicated in regulation of diverse cellular processes of glia and neurons, including cell migration and morphology. Methods: Here, we employed a zebrafish model to analyze the role of LCN2 in CNS cell migration and morphology in vivo. In the first part of this study, we examined the indirect effect of LCN2 on cell migration and morphology of microglia, astrocytes, and neurons cultured in vitro. Results: Conditioned media collected from LCN2-treated astrocytes augmented migration of glia and neurons in the Boyden chamber assay. The conditioned media also increased the number of neuronal processes. Next, in order to further understand the role of LCN2 in the CNS in vivo, LCN2 was ectopically expressed in the zebrafish spinal cord. Expression of exogenous LCN2 modulated neuronal cell migration in the spinal cord of zebrafish embryos, supporting the role of LCN2 as a cell migration regulator in the CNS. Conclusion: Thus, LCN2 proteins secreted under diverse conditions may play an important role in CNS immune and inflammatory responses by controlling cell migration and morphology.

• Clinical and Experimental Pediatrics
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• v.61 no.1
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• pp.24-29
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• 2018

Purpose: The aim of this study was to evaluate the diagnostic accuracy of urinary biomarkers, such as neutrophil gelatinase-associated lipocalin (uNGAL) and ${\beta}-2$ microglobulin (uB2MG), in early detection of urinary tract infection (UTI) in infants aged <3 months with fever. Methods: A total of 422 infants aged <3 months (male:female=267:155; mean age, 56.4 days), who were admitted for fever, were retrospectively included in this study. We compared uNGAL and uB2MG between the UTI and non-UTI groups at the time of admission. The sensitivity, specificity, accuracy, and area under the curve (AUC) of uNGAL and uB2MG for use in diagnosing UTI were assessed. Results: Among 422 patients, 102 (24.2%) were diagnosed with UTI. Levels of uNGAL were higher in the UTI group than in the non-UTI group (366.6 ng/mL vs. 26.9 ng/mL, P<0.001). Levels of uB2MG were not different between the 2 groups. Multivariate analysis revealed that uNGAL was an independent predictive factor for UTI (P=0.033). The sensitivity, specificity, and accuracy were 90.2%, 92.5%, and 91.9% for uNGAL, and 48.0%, 43.8%, and 44.8% for uB2MG, respectively. AUC of uNGAL was 0.942 and that of uB2MG was 0.407. Conclusion: Accuracy of uNGAL in the diagnosis of UTI is high in febrile infants aged <3 months. uNGAL can help in the early diagnosis and treatment of UTI in infants.

• Journal of Chest Surgery
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• v.47 no.3
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• pp.240-248
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• 2014

Background: Open heart surgery using cardiopulmonary bypass (CPB) is considered one of the most frequent surgical procedures in which acute kidney injury (AKI) is a frequent and serious complication. The aim of the present study was to evaluate the efficiency of neutrophil gelatinase-associated lipocalin (NGAL) as an early AKI biomarker after CPB in cardiac surgery (CS). Methods: Thirty-seven adult patients undergoing CS with CPB were included in this retrospective study. They had normal preoperative renal function, as assessed by the creatinine (Cr) level, NGAL level, and estimated glomerular filtration rate. Serial evaluation of serum NGAL and Cr levels was performed before, immediately after, and 24 hours after the operation. Patients were divided into two groups: those who showed normal immediate postoperative serum NGAL levels (group A, n=30) and those who showed elevated immediate postoperative serum NGAL levels (group B, n=7). Statistical analysis was performed using Statistical Package for the Social Sciences version 18. Results: Of the 37 patients, 6 (6/37, 16.2%) were diagnosed with AKI. One patient belonged to group A (1/30, 3.3%), and 5 patients belonged to group B (5/7, 71.4%). Two patients in group B (2/7, 28.5%) required further renal replacement therapy. Death occurred in only 1 patient (1/37, 2.7%), who belonged to group B. Conclusion: The results of this study suggest that postoperative plasma NGAL levels can be used as an early biomarker for the detection of AKI following CS using CPB. Further studies with a larger sample size are needed to confirm our results.

• Neonatal Medicine
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• v.28 no.2
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• pp.65-71
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• 2021

Purpose: We investigated whether consecutive levels of new emerging renal biomarkers, including serum cystatin C (CysC) and urinary neutrophil gelatinase-associated lipocalin (NGAL)/creatinine (Cr) ratio, were affected by postconceptional age in very-low-birth-weight (VLBW) infants. Methods: Repeatedly measured samples for each infant were divided into four groups according to postnatal age: at birth (stage I), 3 to 7 days postnatally (stage II), 8 to 28 days postnatally (stage III), and >28 days postnatally (stage IV). The association between renal biomarkers and postconceptional age was assessed using Pearson's correlation coefficient, and the mean values of renal biomarkers in the four stages were compared using repeated-measures analysis of variance. Results: For samples measured at birth, serum CysC (r=-0.358, P=0.032) and urinary NGAL/Cr ratio (r=-0.522, P=0.001) were negatively correlated with gestational age, whereas serum Cr (r=0.148, P=0.390) was not. In addition, for all samples measured, serum CysC (r=-0.209, P=0.012), urinary NGAL/Cr ratio (r=-0.536, P<0.001), and serum Cr (r=-0.311, P<0.001) were negatively correlated with postconceptional age. Compared with the mean values of the postnatal age-specific stages, serum CysC showed no significant differences in any of the four stages. However, the urinary NGAL/Cr ratio in stage IV was significantly different from those in stages I to III. Conclusion: Although urinary NGAL/Cr ratio and serum CysC were negatively correlated with postconceptional age considering renal development, serum CysC showed no significant differences in any of the four postnatal age-specific stages. Urinary NGAL/Cr ratio at >28 days postnatally seems to be more affected by postconceptional age than serum CysC in VLBW infants.

• Childhood Kidney Diseases
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• v.24 no.2
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• pp.83-90
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• 2020

Purpose: To investigate the association between urinary neutrophil gelatinase-associated lipocalin (uNGAL) and leukocyte differential count in children with urinary tract infections (UTIs). Methods: A retrospective chart review was performed in children undergoing uNGAL measurements between June 2018 and September 2019. Patients with suspected or diagnosed UTIs were included. The relationship between uNGAL and blood leukocyte differential count was investigated in children. Results: A total of 197 children were included in this study, 119 of whom (60%) had UTIs. The non-UTI patients (n=78) were diagnosed with pneumonia, acute gastroenteritis, viral upper respiratory infection, and others. After adjusting for age, gender, and fever duration, the leukocyte count, monocyte count, and uNGAL levels were higher in the UTI group than in the non-UTI group (P<0.05). uNGAL showed positive correlations with neutrophil counts, monocyte counts, the neutrophil-to-lymphocyte ratio, and the monocyte-to-lymphocyte ratio in the UTI group (P<0.05). uNGAL levels were only associated with the neutrophil-to-lymphocyte ratio in the non-UTI group (P<0.05). In a multivariable logistic regression analysis, only uNGAL was associated with the presence of UTI (P<0.05). The area under the receiver operating characteristic curves for uNGAL and monocyte counts to identify UTI were 0.89 (95% confidence interval (CI): 0.824-0.939; P=0.025) and 0.7 (95% CI: 0.627-0.774; P=0.038), respectively. Conclusions: In children with UTIs, uNGAL levels may be associated with blood leukocyte differential counts. uNGAL measurements and monocyte counts can be helpful in children with suspected UTIs.