OBJECTIVE: The present study aimed to assess Lipocalin-2 (LCN2) expression in patients with papillary thyroid cancer (PTC) and to compare it with multinodular goitre (MNG). We also investigated the correlation between LCN2 expression and clinicopathologic characteristics.
METHODS: This retrospective study included 63 surgically treated adult patients with papillary carcinoma and 65 adult patients with a MNG. Age, gender, physical, radiological and histopathological examinations, and surgical data of the patients were extracted from the hospital records. Size, histological subtype, capsule invasion, multifocality, extrathyroidal extension (ETE), lymph node metastasis (LNM), and immunohistochemical (IHC) studies of the tumour were recorded from the final histopathological reports of patients with PTC. The patient groups were compared in terms of LCN2 expression. The relationships between LCN2 expression and clinicopathological and other IHC parameters were also evaluated in patients with PTC.
RESULTS: LCN2 expression was significantly higher in the PTC group than in the control group. No significant correlation was demonstrated between LCN2 expression and the presence of multifocal disease, capsular invasion, vascular invasion, ETE, and LNM. There was a moderate positive correlation between LCN2 and human bone marrow endothelial cell marker-1 (HBME-1) expressions, however, no correlation was found between LCN2 and cytokeratin-19 (CK19), CD56, and galectin-3.
CONCLUSIONS: LCN2 expression may be a useful biomarker in differentiating benign and malignant lesions of the thyroid gland; however, its expression pattern may not be associated with clinicopathologic characteristics of the PTC and should be investigated in further studies with larger clinical samples.

We investigated the effects of tobacco smoke exposure and abnormal body weight on selected peptide hormones and their association with metabolic and hormonal disorders in women with polycystic ovary syndrome (PCOS). The study group included 88 women with PCOS and 28 women without the disease. In women with PCOS, chemerin, lipocalin, and apelin concentrations were influenced by overweight and obesity status, with the highest concentrations observed in those with a body mass index (BMI) ≥ 30.0. Exposure to tobacco smoke significantly increased only lipocalin-2 concentration. The disease itself did not affect the concentrations of chemerin, lipocalin, and apelin. Additionally, we found a positive correlation between chemerin concentration and fasting glucose, fasting insulin, and triglycerides levels, while a negative correlation was observed with high-density lipoprotein (HDL-C) concentration. In the smoking subgroup, chemerin concentration was positively correlated with free testosterone concentration and the free androgen index and negatively associated with sex hormone-binding globulin concentration. Our findings indicate that abnormal body weight has a stronger impact than tobacco smoke exposure on metabolic and hormonal disorders in women with PCOS, highlighting the important role of weight control in such individuals. However, smoking appears to be an additional factor that intensifies hormonal disorders associated with adipose tissue.

OBJECTIVE: The objective was to evaluate the serum levels of neutrophil gelatinase-associated lipocalin (NGAL), hypoxia-induced factor-1 alpha (HIF-1α), and apelin 13 in patients with acute pulmonary thromboembolism (PE) and to investigate their diagnostic and prognostic role in PE patients with different mortality risk groups.
METHODS: This study was conducted in a tertiary referral center and included 124 subjects with 94 cases of PE and 30 cases of healthy control group. All subjects were 18 years of age or older. The diagnosis of PE was done with computed tomography angiography of the thorax. After the diagnosis of acute PE, the serum levels of neutrophil gelatinase-associated lipocalin (NGAL), hypoxia-induced factor-1 alpha (HIF-1α), and apelin 13 levels were measured with a commercial enzyme-linked immunosorbent assay (ELISA) kit.
RESULTS: The median and IQR (interquartile range) age of patients and control groups were 68 (56-76) and 61.5 (56-67) years, respectively. The majority of patients with PE had risk factors (97.88 %), and only two (2.12 %) had no known risk factors. HIF-1 alpha level was found to be higher in the patient group than in the control group (p = 0.03). At the same time, the HIF-1 alpha level was found to be higher in the high mortality risk group than in the control group, low mortality risk group and intermediate-low mortality risk group (p = 0.000, 0.011, 0.002, respectively). While there was no significant difference in NGAL level between the patient group and the control group, a significant difference was observed between the mortality groups. NGAL level was found to be higher in the high mortality risk group than the control group, low mortality risk group, and medium-low mortality risk group (p = 0.001, 0.000, 0.010, respectively). Apelin 13 levels did not differ significantly in all groups.
CONCLUSIONS: HIF-1 alpha is a promising biomarker in distinguishing between patients and control groups and in identifying those with high mortality risk in the patient group. At the same time, NGAL can be used as a successful biomarker in determining the group with high mortality risk in cases of PE.

Breast cancer is the leading cancer diagnosed in women globally, with brain metastasis emerging as a major cause of death, particularly in human epidermal growth factor receptor 2 positive and triple-negative breast cancer subtypes. Comprehensive understanding of the molecular foundations of central nervous system metastases is imperative for the evolution of efficacious treatment strategies. Lipocalin-2 (LCN2), a secreted iron transport protein with multiple functions, has been linked to the progression of breast cancer brain metastasis (BCBM). In primary tumors, LCN2 promotes the proliferation and angiogenesis of breast cancer cells, triggers the epithelial-mesenchymal transition, interacts with matrix metalloproteinase-9, thereby facilitating the reorganization of the extracellular matrix and enhancing cancer cell invasion and migration. In brain microenvironment, LCN2 undermines the blood-brain barrier and facilitates tumor seeding in the brain by modulating the behavior of key cellular components. In summary, this review meticulously examines the fuel role of LCN2 in BCBM cascade, and investigates the potential mechanisms involved. It highlights the potential of LCN2 as both a therapeutic target and biomarker, indicating that interventions targeting LCN2 may offer improved outcomes for patients afflicted with BCBM.

Crohn\'s disease (CD) is a complex chronic inflammatory disorder with both gastrointestinal and extra-intestinal manifestations associated immune dysregulation. Analyzing 202,359 cells from 170 specimens across 83 patients, we identify a distinct epithelial cell type in both terminal ileum and ascending colon (hereon as \'LND\') with high expression of LCN2, NOS2, and DUOX2 and genes related to antimicrobial response and immunoregulation. LND cells, confirmed by in-situ RNA and protein imaging, are rare in non-IBD controls but expand in active CD, and actively interact with immune cells and specifically express IBD/CD susceptibility genes, suggesting a possible function in CD immunopathogenesis. Furthermore, we discover early and late LND subpopulations with different origins and developmental potential. A higher ratio of late-to-early LND cells correlates with better response to anti-TNF treatment. Our findings thus suggest a potential pathogenic role for LND cells in both Crohn\'s ileitis and colitis.

OBJECTIVE: To study the urinary neutrophil gelatinase-associated lipocalin (NGAL) and beta-2-microglobulin (β2M) levels as markers of tubular damage in children with type 1 diabetes (T1DM).
METHODS: Forty T1DM children and 40 age-matched controls were enrolled. Subjects with coexisting kidney disorder, intake of oral glucose lowering drugs and syndromic diabetes mellitus were excluded. Fasting plasma glucose, glycated hemoglobin (HbA1c), kidney function, urinary albumin-creatinine ratio (UACR), NGAL and β2M were measured and compared in cases and controls.
RESULTS: The median (IQR) age of cases and controls was 10.6 (8, 14.2) and 10.7 (8.4, 13.7) years, respectively. Cases had disease duration of 4 (3, 6.8) years and HbA1c 10.9 (9, 13.1) %. Microalbuminuria was seen in 14 (35 %). Median (IQR) levels of UACR were higher in cases than controls [19.38 (10.27, 35.26) and 6.49 (3.10, 11.65) µg/mg; p<0.001], similarly NGAL/creatinine [352.21 (191.49, 572.45) and 190.54 (125.91, 322.83) ng/mg; p=0.006], unlike β2M/creatinine [1.7 (0.43, 6.02) and 2.12 (1.05, 4.47) µg/mg; p=0.637]. Children with higher HbA1c (≥10 %) had higher urinary ACR and tubular biomarkers than HbA1c<10 % (p>0.05). Urinary ACR showed positive correlation with NGAL/creatinine (r=0.38, p=0.019) and β2M/creatinine (r=0.42, p=0.009).
CONCLUSIONS: Urinary biomarkers NGAL and β2M were elevated in the presence of normal urinary microalbumin levels suggestive of early tubular damage in T1DM.

Extracellular acyl-coenzyme A binding protein [ACBP encoded by diazepam binding inhibitor (DBI)] is a phylogenetically ancient appetite stimulator that is secreted in a nonconventional, autophagy-dependent fashion. Here, we show that low ACBP/DBI plasma concentrations are associated with poor prognosis in patients with anorexia nervosa, a frequent and often intractable eating disorder. In mice, anorexia induced by chronic restraint stress (CRS) is accompanied by a reduction in circulating ACBP/DBI concentrations. We engineered a chemical-genetic system for the secretion of ACBP/DBI through a biotin-activatable, autophagy-independent pathway. In transgenic mice expressing this system in hepatocytes, biotin-induced elevations in plasma ACBP/DBI concentrations prevented anorexia induced by CRS or chemotherapeutic agents including cisplatin, doxorubicin, and paclitaxel. ACBP/DBI reversed the CRS or cisplatin-induced increase in plasma lipocalin-2 concentrations and the hypothalamic activation of anorexigenic melanocortin 4 receptors, for which lipocalin-2 is an agonist. Daily intravenous injections of recombinant ACBP/DBI protein or subcutaneous implantation of osmotic pumps releasing recombinant ACBP/DBI mimicked the orexigenic effects of the chemical-genetic system. In conclusion, the supplementation of extracellular and peripheral ACBP/DBI might constitute a viable strategy for treating anorexia.

UNASSIGNED: The impaired proliferative capacity of alveolar epithelial cells after injury is an important factor causing epithelial repair dysfunction, leading to the occurrence of idiopathic pulmonary fibrosis (IPF). Alveolar type 2 (AT2) cells as the stem cells of alveolar epithelium participate in the repair process after alveolar injury. Lipocalin-2 (LCN2) participates in multiple processes regulating the pathological process of alveolar epithelial cells, but the mechanisms involved are still unclear.
UNASSIGNED: We used a BLM-treated mouse model to characterize the expression of LCN2 in lung fibrosis regions and analyzed the location of LCN2 in alveolar epithelial cells. Moreover, human pulmonary alveolar epithelial cells (HPAEpiCs) were transfected with the LCN2 overexpression plasmid vector in vitro. Recombinant human interleukin-17 (IL-17) protein (rhIL-17) at different concentrations was administered to intervene in HPAEpiCs, observing cell viability and analyzing the concentration-dependent effect of IL-17.
UNASSIGNED: LCN2 was increased in the alveolar epithelium post-BLM injury, and highly expressed LCN2 was mainly concentrated on AT2 cells in BLM-injured lungs. Meanwhile, LCN2-overexpressing HPAEpiCs showed impaired cell viability and cell growth. HPAEpiC intervention with rhIL-17 mildly rescued the impaired cell proliferation induced by LCN2 overexpression, and the effect of IL-17 intervention was partially concentration-dependent.
UNASSIGNED: The results revealed the reversed effect of IL-17 on the impaired proliferative capacity of the alveolar epithelium induced by LCN2 overexpression. The target alveolar epithelial cells regulated by this process were AT2 cells, providing new clues for alveolar epithelium repair after injury and the treatment of lung injury diseases.

Nephrotoxicity, including electrolytic disorders and acute kidney injury (AKI), limits the clinical dosage and utility of platinated antineoplastics such as cisplatin. Cisplatin nephrotoxicity embodies a tubulopathy involving the medullary S2 and S3 segments of the proximal and the distal tubules. Higher dosage extends damage over the cortical S1 segment and intensifies overall injury. However, the standard diagnosis based on plasma creatinine as well as novel injury biomarkers lacks enough pathophysiological specificity. Further granularity in the detection of renal injury would help understand the implications of individual damage patterns needed for personalized patient handling. In this article, we studied the association of urinary ganglioside GM2 activator protein (GM2AP) with the patterns of tubular damage produced by 5 and 10 mg/kg cisplatin in rats. Our results show that GM2AP appears in the urine only following damage to the cortical segment of the proximal tubule. The information provided by GM2AP is not redundant with but distinct and complementary to that provided by urinary neutrophil gelatinase-associated lipocalin (NGAL). Similarly, treatment with 150 mg/kg/day gentamicin damages the renal cortex and increases GM2AP urinary excretion; whereas renal ischemia, which does not affect the cortex, has no effect on GM2AP. Because of the key role of the cortical proximal tubule in renal function, we contend GM2AP as a potential diagnostic biomarker to stratify AKI patients according to the underlying damage and follow their evolution and prognosis. Prospectively, urinary GM2AP may help grade the severity of platinated antineoplastic nephrotoxicity by forming part of a non-invasive liquid biopsy.

BACKGROUND: The inflammatory response and scar formation after spinal cord injury (SCI) limit nerve regeneration and functional recovery. Our research group has previously shown that the expression of astrocyte-derived lipocalin 2 (Lcn2) is upregulated after SCI, which correlates with neuronal apoptosis and functional recovery. Therefore, we speculate that astrocyte-specific knockdown of Lcn2 after SCI may lead to a better prognosis.
METHODS: Tissue RNA sequencing, Western blotting, PCR, and immunofluorescence assays were conducted to assess the expression of Lcn2 following SCI in mice. Adeno-associated virus 9 (AAV9) transfection was employed to specifically reduce the expression of Lcn2 in astrocytes, and subsequent evaluations of scarring and inflammation were conducted. In vitro experiments involved treating primary astrocytes with TGF-β or an A1-induced mixture (C1q, TNF-α and IL-1α) following Lcn2 knockdown. Finally, the intrathecal injection of recombinant Lcn2 (ReLcn2) protein was conducted post-injury to further confirm the role of Lcn2 and its underlying mechanism in SCI.
RESULTS: Lcn2 expression was elevated in astrocytes after SCI at 7 dpi (days post injury). Lcn2 knockdown in astrocytes is beneficial for neuronal survival and functional recovery after SCI, and is accompanied by a reduced inflammatory response and inhibited scar formation. The inhibition of SMAD-associated signaling activation was identified as a possible mechanism, and in vitro experiments further confirmed this finding. ReLcn2 further activated SMAD-associated signaling and aggravated motor function after SCI.
CONCLUSIONS: The upregulation of Lcn2 expression in astrocytes is involved in neuroinflammation and scar formation after SCI, and the activation of SMAD-associated signaling is one of the underlying mechanisms.