OBJECTIVE: To explore the contribution of ferroptosis to myocardial injury in mouse models of sepsis and the role lipocalin-2 (Lcn2) in ferroptosis. METHODS: Adult male C57BL/6 mice were randomized equally into sham-operated group, cecal ligation and puncture (CLP)-induced sepsis group, and CLP + Fer-1 group where the mice received intraperitoneal injection of 5 mg/mL Fer-1 (5 mg/kg) 1 h before CLP. The left ventricular functions (including LVEF%, LVFS%, LVIDd and LVIDs) of the mice were assessed by echocardiography at 24 h after CLP. Myocardial injury in the mice was observed with HE staining, and the changes of myocardial ultrastructure and mitochondria were observed using transmission electron microscopy (TEM). Serum TNF-α level was measured with ELISA, and the changes of myocardial iron content were detected using tissue iron kit. The protein expressions of myocardial Lcn2, glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) were determined with Western blotting. RESULTS: The septic mice showed significantly decreased LVEF%, LVFS% and LVIDd and increased LVIDs at 24 h after CLP (P < 0.05), and these changes were significantly improved by Fer-1 treatment. Sepsis caused obvious myocardial pathologies and changes in myocardial ultrastructure and mitochondria, which were significantly improved by Fer-1 treatment. Fer-1 treatment also significantly ameliorated sepsis-induced elevations of serum TNF-α level, myocardial tissue iron content, and Lcn2 protein expression and the reduction of GPX4 and FSP1 protein expression levels (P < 0.05). CONCLUSION GPX4- and FSP1-mediated ferroptosis are involved in myocardial injury in mice with CLP-induced sepsis, and inhibition of ferroptosis can attenuate septic myocardial injury, in which Lcn2 may play a role.
Animals ; Ferroptosis ; Heart Injuries ; Lipocalin-2 ; Male ; Mice ; Mice, Inbred C57BL ; Sepsis/metabolism*

Acute-Phase Proteins ; metabolism ; Animals ; Female ; Hepatitis, Autoimmune ; immunology ; metabolism ; pathology ; Interleukin-17 ; metabolism ; Lipocalin-2 ; Lipocalins ; metabolism ; Liver ; pathology ; Mice ; Mice, Inbred BALB C ; Oncogene Proteins ; metabolism

Neutrophil gelatinase-associated lipocalin (NGAL) is a member of the lipocalin family. As a novel adipokine, it widely presents in the tissues under the condition of metabolic disorders. More and more studies suggest that NGAL might be a marker for a variety of diseases associated with lipid metabolism. It is likely that NGAL plays an important role in obese-inflammation-induced metabolic syndrome,insulin resistance, glucose and lipid metabolism, endothelial dysfunction and atherosclerosis pathway.
Acute-Phase Proteins ; metabolism ; Atherosclerosis ; Biomarkers ; metabolism ; Humans ; Inflammation ; Insulin Resistance ; Lipocalin-2 ; Lipocalins ; metabolism ; Metabolic Syndrome ; metabolism ; physiopathology ; Obesity ; Proto-Oncogene Proteins ; metabolism

OBJECTIVES: The excretion of urinary vitamin D-binding protein (uVDBP) is related to the occurrence and development of early-stage renal damage in patients with Type 2 diabetes (T2DM). This study aims to explore the significance of detecting uVDBP in T2DM patients and its relationship with renal tubules, and to provide a new direction for the early diagnosis of T2DM renal damage. METHODS: A total of 105 patients with T2DM, who met the inclusion criteria, were included as a patient group, and recruited 30 individuals as a normal control group. The general information and blood and urine biochemical indicators of all subjects were collected; the levels of uVDBP, and a marker of tubular injury [urine kidney injury molecule 1 (uKIM-1), urine neutrophil gelatinase-associated lipocalin (uNGAL) and urine retinol-binding protein (uRBP)] were detected by enzyme-linked immunosorbent assay. The results were corrected by urinary creatinine (Cr) to uVDBP/Cr, uKIM-1/Cr, uNGAL/Cr and uRBP/Cr. The Pearson's and Spearman's correlation tests were used to analyze the correlation between uVDBP/Cr and urine albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate (eGFR) and markers of tubular injury, and multivariate linear regression and receiver operating characteristic curve were used to analyze the correlation between uVDBP/Cr and UACR or eGFR. RESULTS: Compared with the normal control group, the uVDBP/Cr level in the patient group was increased (P<0.05), and which was positively correlated with UACR (r=0.774, P<0.01), and negatively correlated with eGFR (r=-0.397, P<0.01). There were differences in the levels of uKIM-1/Cr, uNGAL/Cr, and uRBP/Cr between the 2 groups (all P<0.01). The uVDBP/Cr was positively correlated with uKIM-1/Cr (r=0.752, P<0.01), uNGAL/Cr (r=0.644, P<0.01) and uRBP/Cr (r=0.812, P<0.01). The sensitivity was 90.0% and the specificity was 82.9% (UACR>30 mg/g) for evaluation of uVDBP/Cr on T2DM patients with early-stage renal damage, while the sensitivity was 75.0% and the specificity was 72.6% for evaluation of eGFR on T2DM patients with early-stage renal damage. CONCLUSIONS The uVDBP/Cr can be used as a biomarker in early-stage renal damage in T2DM patients.
Humans ; Diabetes Mellitus, Type 2/complications* ; Creatinine ; Vitamin D-Binding Protein/urine* ; Lipocalin-2/urine* ; Kidney/metabolism* ; Glomerular Filtration Rate ; Biomarkers

Acute-Phase Proteins ; metabolism ; Biomarkers ; metabolism ; urine ; Cytokines ; metabolism ; Fatty Acid-Binding Proteins ; metabolism ; Hepatitis A Virus Cellular Receptor 1 ; Humans ; Kidney Failure, Chronic ; metabolism ; urine ; Lipocalin-2 ; Lipocalins ; metabolism ; Membrane Glycoproteins ; metabolism ; Proteomics ; Proto-Oncogene Proteins ; metabolism ; Receptors, Virus ; metabolism

Insufficient remyelination due to impaired oligodendrocyte precursor cell (OPC) differentiation and maturation is strongly associated with irreversible white matter injury (WMI) and neurological deficits. We analyzed whole transcriptome expression to elucidate the potential role and underlying mechanism of action of lipocalin-2 (LCN2) in OPC differentiation and WMI and identified the receptor SCL22A17 and downstream transcription factor early growth response protein 1 (EGR1) as the key signals contributing to LCN2-mediated insufficient OPC remyelination. In LCN-knockdown and OPC EGR1 conditional-knockout mice, we discovered enhanced OPC differentiation in developing and injured white matter (WM); consistent with this, the specific inactivation of LCN2/SCl22A17/EGR1 signaling promoted remyelination and neurological recovery in both atypical, acute WMI due to subarachnoid hemorrhage and typical, chronic WMI due to multiple sclerosis. This potentially represents a novel strategy to enhance differentiation and remyelination in patients with white matter injury.
Mice ; Animals ; Remyelination/physiology* ; Oligodendrocyte Precursor Cells/metabolism* ; White Matter ; Subarachnoid Hemorrhage/metabolism* ; Lipocalin-2/metabolism* ; Early Growth Response Protein 1/metabolism* ; Oligodendroglia/metabolism* ; Mice, Knockout ; Cell Differentiation/physiology* ; Brain Injuries/metabolism*

OBJECTIVE: To determine the pathological mechanism and prevent heart-renal syndrome after heart valve replacement surgery. METHODS: A total of 46 patients were admitted for selective valve replacement, and divide into 3 groups randomly: a control group (Con, n=16), a remote ischemic perconditioning (RIPerC) group (n=15) and a remote ischemic postconditioning (RIPostC) group (n=15). The serum creatinine (SCr), blood urea nitrogen (BUN), serum heme oxygennase-1 (HO-1), serum iron and urinary neutrophil gelatinase associated lipocalin (NGAL) level in the 3 groups were compared preoperatively and 6, 12, 24, 48 h after aortic cross-release. RESULTS: Compared with the preoperative level, the SCr, BUN, urinary NGAL, serum iron (6 and 12 h) and serum HO-1 values were significantly increased after the heart valve replacement surgery in the control patients, RIPreC and RIPostC groups (P<0.05). Compared with the control group, the serum HO-1 was significantly increased at 6, 12, 24, 48 h after the heart valve replacement surgery in both the RIPerC and RIPostC groups (P<0.05); the SCr, BUN, urinary NGAL and serum iron values were decreased at 6, 12, 24, 48 h after the heart valve replacement surgery in both the RIPerC and RIPostC groups (P>0.05). CONCLUSION Abnormal change in urinary NGAL, serum iron and HO-1 can be used as early warning indicators of acute kidney injury when cardio-renal syndrome occurrs among patients under heart valve replacement surgery. Remote ischemic conditioning plays a preventive role in the occurrence of cardio-renal syndrome and renal protection.
Acute Kidney Injury ; metabolism ; Acute-Phase Proteins ; metabolism ; Blood Urea Nitrogen ; Cardiac Surgical Procedures ; adverse effects ; Creatinine ; blood ; Heme Oxygenase-1 ; metabolism ; Humans ; Iron ; blood ; Ischemic Postconditioning ; Ischemic Preconditioning ; Lipocalin-2 ; Lipocalins ; metabolism ; Proto-Oncogene Proteins ; metabolism

OBJECTIVES: Sufentanil has a good protective effect on myocardial and liver injury caused by ischemia reperfusion (IR), but its protective effect on kidney is still unclear. This study aims to investigate whether sufentanil can prevent IR-induced acute kidney injury (AKI) and to determine whether its efficacy is related to miR-145-mediated autophagy. METHODS: A total of 40 rats were randomly divided into 5 groups (n=8 in each group): A sham group, an IR group, a sufentanil group, a sufentanil+miR-145 inhibitor control group (an anti-NC group) and a sufentanil+miR-145 inhibitor group (an anti-miR-145 group). Except for the sham group, the other groups established a rat AKI model induced by IR. The sufentanil group, the sufentanil+anti-NC group, and the sufentanil+anti-miR-145 were injected with sufentanil (1 μg/kg) through femoral vein 30 min before ischemia. The sufentanil+anti-NC group and the sufentanil+anti-miR-145 group were injected with miR-145 inhibitor control or anti-miR-145 (80 mg/kg) through the tail vein before sufentanil pretreatment. The structure and function of kidneys harvested from the rats were evaluated, and the protein levels of autophagy-related proteins, oxidative stress levels, and apoptosis levels were measured. RESULTS: Compared with the IR group, the renal structure and function were improved in the sufentanil group. The levels of blood urea nitrogen (BUN), creatinine (Cr), urinary kidney injury molecule 1 (KIM-1), neutrophil gelatinase related lipid transporter (NGAL), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and ROS were significantly decreased (all P<0.05). In addition, compared with the IR group, the levels of Beclin-1 and LC3 in renal tissues in the sufentanil group were significantly increased (both P<0.05), and the apoptosis in renal tissues was significantly reduced (P<0.05). Compared with the sufentanil+anti-NC group, the levels of BUN, Cr, KIM-1, NGAL, TNF-α, IL-1β, IL-6 and ROS in the sufentanil+anti-miR-145 group were significantly increased (all P<0.05), the levels of Beclin-1 and LC3 in renal tissues were significantly decreased (both P<0.05), and the apoptosis in renal tissues was significantly increased (P<0.05). CONCLUSIONS Sufentanil can prevent the AKI induced by IR, which is related to the up-regulation of miR-145-mediated autophagy.
Animals ; Rats ; Acute Kidney Injury/pathology* ; Antagomirs ; Autophagy ; Beclin-1/metabolism* ; Creatinine ; Interleukin-6/metabolism* ; Ischemia ; Kidney/pathology* ; Lipocalin-2 ; MicroRNAs/metabolism* ; Reactive Oxygen Species ; Reperfusion ; Reperfusion Injury/metabolism* ; Sufentanil/therapeutic use* ; Tumor Necrosis Factor-alpha ; Up-Regulation

OBJECTIVETo explore whether the amount of lipocalin-2 in the biofluid could reflect the onset of sepsis-induced acute lung injury (ALI) in mice.

METHODSLipopolysaccharide (LPS, 10 mg/kg) injection or cecal ligation and puncture (CLP) was performed to induce severe sepsis and ALI in C57 BL/6 male mice randomly divided into 5 groups (n=10 in each group): group A (intraperitoneal LPS injection), group B (intravenous LPS injection via tail vein), group C (CLP with 25% of the cecum ligated), group D (CLP with 75% of the cecum ligated), and the control group (6 sham-operation controls plus 4 saline controls). All the mice received volume resuscitation. Measurements of pulmonary morphological and functional alterations were used to identify the presence of experimental ALI. The expressions of lipocalin-2 and interleukin (IL)-6 in serum, bronchoalveolar lavage fluid (BALF), and lung tissue were quantified at both protein and mRNA levels. The overall abilities of lipocalin-2 and IL-6 tests to diagnose sepsis-induced ALI were evaluated by generating receiver operator characteristic curves (ROC) and computing area under curve (AUC).

RESULTSIn both group B and group D, most of the main features of experimental ALI were reproduced in mice, while group A and group C showed septic syndrome without definite evidence for the presence of ALI. Compared with septic mice without ALI (group A+group C), lipocalin-2 protein expression in septic mice with ALI (group B+group D) was significantly up-regulated in BALF (P<0.01) and in serum (P<0.01), and mRNA expression boosted in lung tissues (all P<0.05). Lipocalin-2 tests performed better than IL-6 tests in recognizing sepsis-induced ALI cases, evidenced by the larger AUC of the former (BALF tests, 0.8800 versus 0.6625; serum tests, 0.8500 versus 0.7000). Using a dual cutoff system to diagnose sepsis-induced ALI, BALF lipocalin-2 test exhibited the highest positive likelihood ratio (13.000) and the lowest negative likelihood ratio (0.077) among the tests of lipocalin-2 and IL-6 in blood and BALF. A statistically significant correlation was found between lipocalin-2 concentration in BALF and that in serum (Spearman r=0.8803, P<0.0001).

CONCLUSIONSLipocalin-2 expression is significantly up-regulated in septic ALI mice compared with those without ALI. Lipocalin-2 tests with a dual cutoff system could be an effective tool in distinguishing experimental ALI cases.

Acute-Phase Proteins ; metabolism ; Animals ; Base Sequence ; Bronchoalveolar Lavage Fluid ; DNA Primers ; Lipocalin-2 ; Lipocalins ; metabolism ; Lung Injury ; complications ; diagnosis ; Male ; Mice ; Mice, Inbred C57BL ; Oncogene Proteins ; metabolism ; Real-Time Polymerase Chain Reaction ; Sepsis ; complications

Biomarkers ; urine ; Cross-Sectional Studies ; Diabetes Mellitus, Type 2 ; pathology ; urine ; Enzyme-Linked Immunosorbent Assay ; Hepatitis A Virus Cellular Receptor 1 ; metabolism ; Humans ; Intracellular Signaling Peptides and Proteins ; urine ; Kidney Diseases ; pathology ; urine ; Lipocalin-2 ; urine ; Membrane Proteins ; urine ; Sialoglycoproteins ; urine ; Tissue Inhibitor of Metalloproteinase-2 ; urine