Plasma Neutrophil Gelatinase-Associated Lipocalin Associates with New-Onset Chronic Kidney Disease in the General Population.

Circulating levels of neutrophil gelatinase-associated lipocalin (NGAL) have been associated with acute kidney injury and the severity and progression of chronic kidney disease (CKD). This study investigated its potential utility as a biomarker for the risk of new-onset CKD in a population-based cohort study. Individuals without CKD at baseline (n = 4660) who participated in the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) prospective population-based cohort study in the Netherlands were included. Baseline plasma NGAL concentrations were investigated for their associations with new-onset CKD, defined as a composite outcome of an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2, urinary albumin excretion (UAE) > 30 mg/24-h, or both. Mean (±SD) plasma NGAL concentrations were 104.0 (±34.7) µg/L and median eGFR was 96 [IQR: 85.3-105.8] mL/min/1.73 m2. After median follow-up of 8.3 [IQR: 7.8-8.9] years, 467 participants developed new-onset CKD. Plasma NGAL concentrations were significantly associated with an increased risk of new-onset CKD (hazard ratio [HR] per doubling 1.35 [95% CI: 1.11-1.63], p = 0.002), even after adjustment for potentially confounding factors (1.37 [1.09-1.73], p = 0.007) except baseline eGFR (1.09 [0.86-1.37], p = 0.490). In secondary analyses, plasma NGAL concentrations were significantly associated with new-onset CKD as defined by eGFR < 60 mL/min/1.73 m2 alone (adjusted HR per doubling 2.54 [1.69-3.80], p < 0.001), which was abrogated after adjustment for eGFR (1.05 [0.69-1.59], p = 0.828), also when UAE > 30 mg/24-h was set as individual outcome (1.05 [0.82-1.35], p = 0.705). Higher plasma NGAL concentrations are associated with an increased risk of developing CKD in the general population. This association is dependent on renal function, and mainly driven by new-onset CKD as defined by renal function decline.

Role of lipocalin 2 in stroke.

Stroke is the second leading cause of death worldwide; however, the treatment choices available to neurologists are limited in clinical practice. Lipocalin 2 (LCN2) is a secreted protein, belonging to the lipocalin superfamily, with multiple biological functions in mediating innate immune response, inflammatory response, iron-homeostasis, cell migration and differentiation, energy metabolism, and other processes in the body. LCN2 is expressed at low levels in the brain under normal physiological conditions, but its expression is significantly up-regulated in multiple acute stimulations and chronic pathologies. An up-regulation of LCN2 has been found in the blood/cerebrospinal fluid of patients with ischemic/hemorrhagic stroke, and could serve as a potential biomarker for the prediction of the severity of acute stroke. LCN2 activates reactive astrocytes and microglia, promotes neutrophil infiltration, amplifies post-stroke inflammation, promotes blood-brain barrier disruption, white matter injury, and neuronal death. Moreover, LCN2 is involved in brain injury induced by thrombin and erythrocyte lysates, as well as microvascular thrombosis after hemorrhage. In this paper, we review the role of LCN2 in the pathological processes of ischemic stroke; intracerebral hemorrhage; subarachnoid hemorrhage; and stroke-related brain diseases, such as vascular dementia and post-stroke depression, and their underlying mechanisms. We hope that this review will help elucidate the value of LCN2 as a therapeutic target in stroke.

Assessment of Urinary Level of Neutrophil Gelatinaseassociated Lipocalin (NAGL) in Children with Renal Scar Due to Vesicoureteral Reflux.

INTRODUCTION: Renal scarring is a serious complications of urinary tract infection and vesicoureteral reflux (VUR). The dimercaptosuccinic acid (DMSA) scan is the gold standard method for diagnosing renal scars but is an expensive procedure that risks ionizing materials and is not available to everyone. Neutrophil gelatinase-associated lipocalin (NGAL) increases following inflammation, infection, and acute kidney injury in the urine. The aim of this study was to evaluate the urinary level of NGAL and determine its diagnostic value in renal scarring. METHODS: Patients aged 3 to 60 months with pyelonephritis were included in this study. Voiding cystourethrography (VCUG) was performed in the presence of hydronephrosis on ultrasonography. Children with VUR underwent DMSA scans six months after successful treatment of pyelonephritis., Patients were divided into two groups based on the result of DMSA scan: those with and those without renal scars. Levels of urinary NGAL were measured in both groups. RESULTS: Ninety-two children with VUR (grades 2 to 5) were studied, of whom 40 had renal scars and 52 did not. The urinary level of NGAL at the cutoff point of 284 ng/dL had 70% sensitivity and 100% specificity for the detection of renal scars and was higher in patients with renal scars. (P < .05). CONCLUSION: The urinary level of NGAL is considerably higher in children with renal scarring. It is not a good test for screening and early diagnosis due to its low sensitivity, although it can identify renal scars caused by VUR with high specificity.  DOI: 10.52547/ijkd.6951.

Research Progress on Lipocalin-2 in Diabetic Encephalopathy.

Diabetic encephalopathy is a central nervous complication of diabetes mellitus which is characterized by cognitive impairment and structural and neurochemical abnormalities, which is easily neglected. Lipocalin-2 (LCN2) is a 25 kDa transporter in the lipocalin family that can transport small molecules, including fatty acids, iron, steroids, and lipopolysaccharides in the circulation. Recently, LCN2 has been found to be a significant regulator of insulin resistance and glucose homeostasis. Numerous studies have shown that LCN2 is connected to central nervous system abnormalities, including neuroinflammation and neurodegeneration, while the latest researches have found that LCN2 is closely related to the development of diabetic encephalopathy. Nevertheless, its precise role in the pathogenesis of diabetic encephalopathy remains to be determined. In this paper, we review recent evidence on the role of LCN2 in diabetic encephalopathy from multiple perspectives in order to decipher the impact of LCN2 in both the aetiology and treatment of diabetic encephalopathy.

Component-Resolved Diagnosis Based on a Recombinant Variant of Mus m 1 Lipocalin Allergen.

Exposure to the Mus m 1 aeroallergen is a significant risk factor for laboratory animal allergy. This allergen, primarily expressed in mouse urine where it is characterized by a marked and dynamic polymorphism, is also present in epithelium and dander. Considering the relevance of sequence/structure assessment in protein antigenic reactivity, we compared the sequence of the variant Mus m 1.0102 to other members of the Mus m 1 allergen, and used Discotope 2.0 to predict conformational epitopes based on its 3D-structure. Conventional diagnosis of mouse allergy is based on serum IgE testing, using an epithelial extract as the antigen source. Given the heterogeneous and variable composition of extracts, we developed an indirect ELISA assay based on the recombinant component Mus m 1.0102. The assay performed with adequate precision and reasonable diagnostic accuracy (AUC = 0.87) compared to a routine clinical diagnostic test that exploits the native allergen. Recombinant Mus m 1.0102 turned out to be a valuable tool to study the fine epitope mapping of specific IgE reactivity to the major allergen responsible for mouse allergy. We believe that advancing in its functional characterization will lead to the standardization of murine lipocalins and to the development of allergen-specific immunotherapy.

Tumor-derived OBP2A promotes prostate cancer castration resistance.

Androgen deprivation therapy (ADT) is a systemic therapy for advanced prostate cancer (PCa); although most patients initially respond to ADT, almost all cancers eventually develop castration-resistant PCa (CRPC). Currently, most research focuses on castration-resistant tumors, and the role of tumors in remission is almost completely ignored. Here, we report that odorant-binding protein (OBP2A) released from tumors in remission during ADT catches survival factors, such as CXCL15/IL8, to promote PCa cell androgen-independent growth and enhance the infiltration of myeloid-derived suppressor cells (MDSCs) into tumor microenvironment, leading to the emergence of castration resistance. OBP2A knockdown significantly inhibits CRPC and metastatic CRPC development and improves therapeutic efficacy of CTLA-4/PD-1 antibodies. Treatment with OBP2A-binding ligand α-pinene interrupts the function of OBP2A and suppresses CRPC development. Furthermore, α-pinene-conjugated doxorubicin/docetaxel can be specifically delivered to tumors, resulting in improved anticancer efficacy. Thus, our studies establish a novel concept for the emergence of PCa castration resistance and provide new therapeutic strategies for advanced PCa.

Identification and characterization of lipocalin-type prostaglandin D2 synthase homologs in the urine of male rockfish.

Black rockfish (Sebastes schlegelii) and its relatives are viviparous marine fish. Males produce urinary proteins during the copulation season; however, the identity of these proteins was unknown. In this study, we focused on high-molecular-weight urinary proteins (HMWups) in male black rockfish. The HMWups were identified by liquid chromatography and tandem mass spectrometry (LC-MS/MS) of urine. In silico analyses of RNA-seq data predicted the tissue distribution of candidate HMWup transcripts and their gene structures. Candidate cDNAs were cloned and a recombinant protein of a major candidate was prepared. Western blotting of urine using an antiserum against the recombinant protein was performed to reconfirm the LC-MS/MS results. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry were employed to validate the prediction by RNA-seq and identify the cells producing HMWups, respectively. LC-MS/MS, in conjunction with Western blotting and cDNA cloning, identified the HMWups as lipocalin-type prostaglandin D2 synthase (l-PGDS) homologs. RNA-seq analyses and qRT-PCR revealed that the l-PGDS homolog transcripts were dominantly expressed in the testis and male kidney; Sertoli cells and epithelial cells in the renal tubules were immunoreactive. These results indicated that major protein components in the urine of male black rockfish are l-PGDS homologs, potentially produced by the renal tubules in the kidney. Male rockfish (genus Sebastes) are thought to release unknown pheromone substances during mating behavior. The knowledge and tools obtained in this study empower research into the role(s) of HMWups in pheromone systems underlying rockfish reproduction. No protein-type teleost pheromone has heretofore been discovered.

The Utility of Novel Kidney Injury Biomarkers in Early Detection of CSA-AKI.

Cardiac surgery-associated acute kidney injury (CSA-AKI) is one of the most common complications of cardiac surgery procedures. In this study, the authors attempt to provide new data regarding the application of novel kidney injury biomarkers in the early diagnostics of CSA-AKI. 128 adult patients undergoing elective cardiac surgery procedures with the use of cardiopulmonary by-pass (CPB) were enrolled in this study. Novel kidney injury biomarkers were marked in the plasma and urine 6 h after weaning from the CPB. A significant difference in the postoperative biomarkers' concentration between the AKI and no-AKI group was found, regarding plasma IL-8, plasma TNF-α and urine NGAL, normalized for creatinine excretion (NGAL/Cr). These were also independent predictors of CSA-AKI. An independent risk factor for CSA-AKI proved to be preoperative CKD. Plasma IL-8 and TNF-α, as well as urine NGAL/Cr, are independent early indicators of CSA-AKI and pose a promising alternative for creatinine measurements. The cut-off points for these biomarkers proposed in this investigation should be confronted with more data and revised to achieve a suitable diagnostic value.

Anti-inflammatory effects of the prostaglandin D2/prostaglandin DP1 receptor and lipocalin-type prostaglandin D2 synthase/prostaglandin D2 pathways in bacteria-induced bovine endometrial tissue.

Dairy cows often develop different degrees of endometritis after calving and this is attributed to pathogenic bacterial infections such as by Escherichia coli and Staphylococcus aureus. Infection of the bovine endometrium causes tissue damage and increases the expression of prostaglandin D2 (PGD2), which exerts anti-inflammatory effects on lung inflammation. However, the roles of PGD2 and its DP1 receptor in endometritis in cows remain unclear. Here, we examined the anti-inflammatory roles of the lipocalin-type prostaglandin D2 synthase (L-PGDS)/PGD2 and DP1 receptor regulatory pathways in bovine endometritis. We evaluated the regulatory effects of PGD2 on inflammation and tissue damage in E. coli- and S. aureus-infected bovine endometrial cells cultured in vitro. We found that the secretion of pro-inflammatory cytokines interleukin (IL)-6, IL-1ß, and tumour necrosis factor (TNF)-α as well as expression of matrix metalloproteinase (MMP)-2, platelet-activating factor receptor (PAFR), and high mobility group box (HMGB)-1 were suppressed after DP1 receptor agonist treatment. In contrast, IL-6, IL-1ß, and TNF-α release and MMP-2, PAFR, and HMGB-1 expression levels were increased after treatment of bovine endometrial tissue with DP1 receptor antagonists. DP1-induced anti-inflammatory effects were dependent on cellular signal transduction. The L-PGDS/PGD2 pathway and DP1 receptor induced anti-inflammatory effects in bovine endometrium infected with S. aureus and E. coli by inhibiting the mitogen-activated protein kinase and nuclear factor-κB signalling pathways, thereby reducing tissue damage. Overall, our findings provide important insights into the pathophysiological roles of PGD2 in bovine endometritis and establish a theoretical basis for applying prostaglandins or non-steroidal anti-inflammatory drugs for treating endometrial inflammatory infertility in bovines.

Urinary Neutrophil Gelatinase-Associated Lipocalin Predicts Intensive Care Unit Admission Diagnosis: A Prospective Cohort Study.

Background: Acute kidney injury (AKI) is most commonly caused by tubular injury and is associated with a wide variety of critical illnesses. It is well known that urinary biomarkers can lead to the early identification of AKI. However, the ability of urinary biomarkers to distinguish between different types of critical illness has been less studied. Methods: In this prospective cohort study, urinary neutrophil gelatinase-associated lipocalin (uNGAL) was measured in 107 patients consecutively admitted to the ICUs in our tertiary medical center. uNGAL samples were collected within 3-6 hours of admission to an ICU and measured by ELISA. All data were analyzed using R statistical software, and univariate analysis was used to determine the correlations of uNGAL levels with AKI stage, admission diagnoses, and ICU course. Results: uNGAL level increased by a mean of 24-fold (SD 10-59) in ICU patients with AKI and demonstrated a significant correlation with the different AKI stages. uNGAL predicted the need for RRT, with values increased by more than 15-fold (P<0.05) in patients needing RRT, and remained a useful tool to predict AKI in ICU patients with a urinary tract infection. uNGAL level was correlated with certain ICU admitting diagnoses whereby uNGAL levels were lower in ICU patients with cardiogenic shock compared with other admission diagnoses (ß=-1.92, P<0.05). Conclusions: uNGAL can be used as an early predictor of AKI and its severity in patients admitted to the ICU, including the need for RRT. uNGAL may also help in distinguishing patients with cardiogenic shock from those with other critical illnesses and identifying those at risk for poor outcomes irrespective of the presence of AKI.

Neutrophil Gelatinase-Associated Lipocalin as Potential Predictive Biomarker of Melanoma and Non-Melanoma Skin Cancers in Psoriatic Patients: A Pilot Study.

BACKGROUND: Studies have demonstrated a higher risk of nonmelanoma skin cancers (NMSC) and a modestly increased melanoma risk in patients with psoriasis. To date, no biomarkers predictive of evolution have been identified yet. METHODS: The aim of this prospective case-control study was to investigate the potential role of neutrophil gelatinase-associated lipocalin (NGAL) as a predictive biomarker of skin cancers in psoriatic patients. Patients with a diagnosis of psoriasis were enrolled, as well as healthy subjects and patients with skin cancers as controls. Plasma protein expression of NGAL, metalloproteinases (MMP)-2, and MMP-9 was performed by an enzyme-linked immunosorbent assay (ELISA). In all the patients who developed skin cancer at follow-up, NGAL, MMP-2, and MMP-9 serum levels were dosed again. RESULTS: Plasma NGAL levels were significantly higher in psoriatic patients with NMSC than without (182.3 ± 36.6 ng/mL vs. 139.9 ± 39.3 ng/mL) (p < 0.001). Plasma NGAL levels were significantly higher (p < 0.00001) in patients with psoriasis and NMSC than in patients with skin tumors without psoriasis (182.3 vs. 122.9). Patients with psoriasis who developed NMSC at follow-up showed increased plasma MMP-9 levels. CONCLUSION: NGAL seems to play a role in the pathogenesis of NMSC but not melanoma in patients with psoriasis.

The Importance of Neutrophil Gelatinase - Associated Lipocalin and Liver Type Fatty Acid Binding Protein in Acute Kidney Injury.

BACKGROUND: The most important factor in the diagnosis of AKI is to accurately and early detect the damage that occurs in the kidney before the filtration capacity of the kidney decreases. Therefore, we discussed the use of NGAL and L-FABP in the early diagnosis of acute kidney injury, evaluation of clinical severity and prognosis as well as prediction of hemodialysis decision in this prospective study. METHODS: We studied 82 participants which included 41 patients aged 18 years and older with the diagnosis of acute kidney injury. We compared the renal function tests collected at 0 and 6 hours with the plasma NGAL and LFABP levels measured using ELISA. Acute kidney injury was defined as serum creatinine increase of 0.3 mg/dL in the last 48 hours, or an increase more than 1.5 times, or an increase in the basal serum creatinine value in the last seven days, or less than 0.5/mL/kg of urine volume within six hours. We tested the power of these new biomarkers in the early diagnosis, and prediction of hemodialysis and survival of the patients with AKI using ROC analysis. RESULTS: Fifteen (36.6%) of the patients were anuric and 26 (63.4%) were oliguric. Twenty-one (51.2%) patients were KDIGO Stage 3. Seventeen (41.5%) patients underwent hemodialysis. In the patient group, the mean NGAL level was 289.7 ± 117.4 ng/mL and the mean L-FABP level was 232.7 ± 72.8. Eleven (26.9%) of 41 patients died within the first 24 hours. In the dead patients, the mean plasma NGAL level was statistically significantly high (p = 0.005). The mean NGAL level was found to be statistically increased in correlation with the severity of acute kidney injury in patients (p < 0.05). To predict acute kidney injury, the ROC analysis showed that the area under the curve (AUC) was 0.819 (95% confidence interval (CI): 0.729 - 0.909) (p < 0.001) for plasma NGAL level, and the area under the curve (AUC) was 0.891 (95% confidence interval (CI): 0.822 - 0.959) for plasma L-FABP level (p < 0.001). CONCLUSIONS: Our study provides evidence that NGAL and L-FABP are effective biomarkers for early detection of AKI as well as predicting clinical severity and hemodialysis.

[Preclinical evaluation of a veno-venous bypass device for liver transplantation based on the principle of magnetic levitation drive].

Objective: To explore the performance of a self-made venous-venous bypass (VVB) device for liver transplantation based on the principle of magnetic levitation drive. Methods: Experimental study was conducted from August 2020 to January 2022. Eight Bama minipigs underwent VVB of hepatic portal vein-femoral vein-internal jugular vein after occlusion of hepatic portal vein and inferior vena cava. The animals were divided into two groups according to the VVB devices used during VVB. A self-made VVB device was used in group A(n=5),and an imported VVB device was used in group B(n=3). The hemodynamic changes of the two groups of animals were compared at 6 time points including before vascular occlusion, during vascular occlusion, 30 minutes, 60 minutes, 90 minutes after the start of VVB, and 30 minutes after vascular opening. In addition,the changes of blood compatibility indexes,intestinal injury indexes,kidney injury indexes and internal environment indexes of the two groups of animals at each time point were compared. The independent samples t test was used for the quantitative data between the two groups with non-repeated measures,and the repeated measures analysis of variance was used for the quantitative data between the two groups with repeated measures. Results: During the VVB of the two devices,the venous drainage was sufficient,and the main manifestations were that the color of the intestine of the Bama miniature pig was ruddy, the peristalsis was normal, and the urine output was normal. There were no significant differences in hemodynamics,blood injure indexes,intestinal injury indexes,kidney injury indexes,neutropil gelatinase-associated lipocalin,and internal environment indexes(all P>0.05).The indexes at 30 minutes after vascular opening in the group A and the group B were as follows:mean arterial pressure were (71.0±7.7)mmHg(1 mmHg=0.133 kPa) and (74.0±8.7)mmHg,central venous pressure were (7.0±1.4)cmH2O(1 cmH2O=0.098 kPa) and (7.7±0.6)cmH2O,heart rate were (131±10) beats/minutes and (132±8)beats/minutes; red blood cell count were (6.43±0.89)×1012/L and (6.32±0.58)×1012/L,hemoglobin were (108.4±5.9)g/L and (110.0±3.5)g/L,free hemoglobin were (78.28±3.96)mg/L and (78.08±4.54)mg/L; intestinal fatty acid binding protein were (2.27±0.49)µg/L and (2.40±0.78)µg/L;creatinine were (68.30±9.77)µmol/L and (79.90±26.91)µmol/L,blood urea nitrogen were (3.94±1.39)mmol/L and (3.45±0.65)mmol/L;neutropil gelatinase-associated lipocalin were (4.02±0.53) µg/L and (3.86±0.23)µg/L;pH value were 7.27±0.04 and 7.23±0.03,lactic acid were (6.18±2.62)mmol/L and (4.30±0.50)mmol/L,concentrations of Na+ were (136.3±3.0)mmol/L and (137.6±1.6) mmol/L,concentrations of K+ were (3.89±0.42) mmol/L and (3.98±0.17)mmol/L,concentrations of Ca2+ were (1.40±0.03)mmol/L and(1.40±0.04)mmol/L;all indexes in the two group had no differences(all P>0.05). Conclusion: The self-made venous bypass device can be safely and effectively applied to VVB of Bama minipigs,and achieves the same performance as the imported venous bypass device.

Relationship between morning peak phenomenon and early renal injury NGAL in H-type hypertension.

PURPOSE: To investigate the relationship between morning blood pressure surge (MBPS) and neutrophilgelatinase associated lipocalin (NGAL) in patients with H-type hypertension. MATERIALS AND METHODS: A total of 224 patients with diagnosed H-type hypertension [homocysteine (Hcy)≧10umol/L] were selected and underwent 24-hour ambulatory blood pressure monitoring (ABPM). In the morning peak group (115 cases), NGAL and serum cystatin C levels, ß2-microglobulin levels were detected in each group, and general biochemical indicators were also detected. RESULTS: There was no significant difference in the course of hypertension, age, blood glucose, blood lipids, Hcy, BUN, Cr, and UA between the two groups (p > 0.05). CysC, ß2-MG were higher than those in the nonmorning peak group, and the difference was statistically significant (p < 0.05).; Pearson correlation analysis showed that NGAL was moderately and highly correlated with CysC, systolic blood pressure morning peak, ß2-MG, and high (p < 0.05), low-density lipoprotein (LDL-C), and Hcy were lowly correlated (p < 0.05).) and morning peak diastolic blood pressure (p > 0.05); multiple linear stepwise regression analysis indicated that morning peak systolic blood pressure, CysC,ß2-MG, and FBG were the risk factors for NGAL. CONCLUSION: The morning peak of systolic blood pressure in H-type hypertension is an important factor causing kidney injury. Paying attention to the ambulatory blood pressure monitoring and the control of morning peak blood pressure in patients with H-type hypertension, and early screening of NGAL has important clinical significance for the early prevention and treatment of renal injury in patients with H-type hypertension. PLAIN LANGUAGE SUMMARYThe morning peak of blood pressure is closely related to target organ damage.There are few studies on the relationship between morning peak phenomenon and renal damage in patients with H-type hypertension at home and abroad.We investigated the relationship between MBPS and NGAL in H-type hypertensive patients with BUN, Cr and UA in the normal range to provide a clinical basis for early renal protection in hypertensive patients.

The effect of interval and continuous work on markers of acute kidney injury in a hot environment.

PURPOSE: To examine the effect of high-intensity interval work (HIIW) and moderate-intensity continuous work (MICW) on markers of acute kidney injury (AKI) and kidney function in a hot environment. METHODS: Nine males completed 2 h of work (2 × 60 min with 10 min passive rest) in a hot environment (40 °C and 15% relative humidity) as either HIIW [2 min at 80% peak oxygen consumption (VO2peak) and 3 min at 30% VO2peak] or MICW (matched for total work of HIIW). Blood and urine samples were collected immediately before (Pre), after (Post), 1 h (1 h Post), and 24 h after (24 h Post) the trials. Urine flow rate (UFR), creatinine clearance, insulin-like growth factor binding protein 7 (IGFBP7), urinary neutrophil gelatinase-associated lipocalin (uNGAL), and urinary kidney injury marker 1 (uKIM-1) were measured to assess kidney function and injury. RESULTS: Log IGFBP7 (p < 0.01), log uNGAL (p < 0.01), and log uKIM-1 (p = 0.01) all displayed a main effect for time after both HIIW and MICW. IGFBP7 (p = 0.01) and uKIM-1 (p < 0.01), corrected for Uosm, were higher after HIIW compared to MICW at Post, while IGFBP7 was also higher 1 h Post after HIIW compared to MICW (p = 0.02). UFR significantly decreasing from Pre to Post (p < 0.01) and 1 h Post (p < 0.01), but no main effect for condition (p = 0.53). CONCLUSION: Both HIIW and MICW in a hot environment caused an increase in biomarkers of kidney injury (IGFBP7, KIM-1, and NGAL), but HIIW may have a greater impact on biomarkers related to AKI.

Potential neurotoxic activity of diverse molecules released by astrocytes.

Astrocytes are the main support cells of the central nervous system. They also participate in neuroimmune reactions. In response to pathological and immune stimuli, astrocytes transform to reactive states characterized by increased release of inflammatory mediators. Some of these molecules are neuroprotective and inflammation resolving while others, including reactive oxygen species (ROS), nitric oxide (NO), matrix metalloproteinase (MMP)- 9, L-glutamate, and tumor necrosis factor α (TNF), are well-established toxins known to cause damage to surrounding cells and tissues. We hypothesized that similar to microglia, the brain immune cells, reactive astrocytes can release a broader set of diverse molecules that are potentially neurotoxic. A literature search was conducted to identify such molecules using the following two criteria: 1) evidence of their expression and secretion by astrocytes and 2) direct neurotoxic action. This review describes 14 structurally diverse molecules as less-established astrocyte neurotoxins, including C-X-C motif chemokine ligand (CXCL)10, CXCL12/CXCL12(5-67), FS-7-associated surface antigen ligand (FasL), macrophage inflammatory protein (MIP)- 2α, TNF-related apoptosis inducing ligand (TRAIL), pro-nerve growth factor (proNGF), pro-brain-derived neurotrophic factor (proBDNF), chondroitin sulfate proteoglycans (CSPGs), cathepsin (Cat)B, group IIA secretory phospholipase A2 (sPLA2-IIA), amyloid beta peptides (Aß), high mobility group box (HMGB)1, ceramides, and lipocalin (LCN)2. For some of these molecules, further studies are required to establish either their direct neurotoxic effects or the full spectrum of stimuli that induce their release by astrocytes. Only limited studies with human-derived astrocytes and neurons are available for most of these potential neurotoxins, which is a knowledge gap that should be addressed in the future. We also summarize available evidence of the role these molecules play in select neuropathologies where reactive astrocytes are a key feature. A comprehensive understanding of the full spectrum of neurotoxins released by reactive astrocytes is key to understanding neuroinflammatory diseases characterized by the adverse activation of these cells and may guide the development of novel treatment strategies.

Targeted proteomics using parallel reaction monitoring confirms salivary proteins indicative of metastatic triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most aggressive subtype due to the absence of hormonal receptors. Our study aimed to identify and determine the effectiveness of salivary proteins as candidate markers for metastatic TNBC subtype using parallel reaction monitoring mass spectrometry (PRM-MS). Three salivary proteins (lipocalin-1, SMR3B, and plastin-2) that showed significant differential expression in label-free quantitation (LFQ) between TNBC (N = 6) and health subjects (HS; N = 6) were selected for further validation. The developed PRM assay was used to quantify peptides GLST and NNLE (lipocalin-1), VYAL and MINL (Plastin-2) and GPYP, and IPPP (SMR3B) on a different cohort of TNBC patients (N = 20) and HS (N = 20) for evaluating their discriminating performances. Quantitative validation using PRM correlated well with the LFQ results, and 5 peptides from three proteins showed a similar up-or down-regulation. Subsequently, these proteins were validated by Western blot analysis. Compared to one protein's performance as an individual marker, the five-signature panel with salivary GLST, VYAL, MINL, GPYP, and IPPP achieved better performance in differentiating aggressive TNBC and HS with sensitivity (80%) and specificity (95%). Targeted proteomic analysis of the prioritized proteins highlights a peptide-based signature in saliva as the potential predictor to distinguish between TNBC and HS. SIGNIFICANCE OF THE STUDY: This study was designed to identify and quantify potential markers in saliva from the triple-negative breast cancer (TNBC) patients using parallel reaction monitoring assay. Three salivary proteins, Lipocalin-1 (LCN-1), Submaxillary androgen-regulated protein 3B (SMR3B), and Plastin-2 (LCP-1) selected in the discovery-phase were further quantified by targeted proteomics and Western blots. The salivary proteins successfully differentiated TNBC patients from healthy subjects with a sensitivity (80%) and specificity (95%).

Neutrophil Gelatinase-Associated Lipocalin (NGAL) and cystatin C are early biomarkers of acute kidney injury associated with cardiac surgery.

Acute kidney injury (AKI) is a serious complication in as much as half of the patients undergoing cardiac surgery, and early diagnosis and treatment are of the utmost importance. There is a need for robust biomarkers that can detect cardiac surgery-associated AKI (CSA-AKI) prior to rise in plasma creatinine, which typically occurs at least 48 h postoperatively. We compared pre- and 4, 12 and 48 h postoperative plasma (P) neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, urea and creatinine, and urine (U) NGAL, as markers of AKI, in 49 patients (67% men, median age 65 years) scheduled for elective cardiac surgery (e.g. coronary artery bypass graft and/or valve replacement surgery) with the use of extracorporeal circulation. Patients with preoperative sepsis, renal replacement therapy, or estimated glomerular filtration rate <30 mL/min/1.73m2 were excluded. P- and U-NGAL were measured using the Roche Modular P (Roche Diagnostics®) NGAL immunoassay. According to AKIN/KDIGO criteria, nine patients (18%) were diagnosed with CSA-AKI. Compared to patients without CSA-AKI, these patients had significantly higher P-NGAL and P-cystatin C values 4 h (p-values .002 and <.001) and 12 h (p-values <.001 and <.001) postoperatively. The same differences were not observed for U-NGAL. Patients with AKI also had significantly higher P-creatinine 4 and 12 h postoperatively (p-values .001 and <.001), however the rise in P-creatinine was just above the upper reference limit. In conclusion, plasma NGAL and cystatin C seem to detect CSA-AKI earlier than the more commonly used biomarkers creatinine and urea.

Oral exposure to DEHP may stimulate prostatic hyperplasia associated with upregulation of COX-2 and L-PGDS expressions in male adult rats.

Di-(2-ethylhexyl) phthalate (DEHP), a typical environmental endocrine disruptor (EED), can disrupt estrogen and androgen secretion and metabolism process, thus inducing dysfunctional reproduction such as impaired gonadal development and spermatogenesis disorder. Prostaglandin synthases (PGS) catalyze various prostaglandins biosynthesis, involved in inflammatory cascade and tumorigenesis. Yet, little is known about how PGS may impact prostatic hyperplasia development and progression. This study concentrates predominantly on the potential prostatic toxicity of DEHP exposure and the mediating role of PGS. In vivo study, adult male rats were administered via oral gavage 30 µg/kg/d, 90 µg/kg/d, 270 µg/kg/d, 810 µg/kg/d DEHP or vehicle for four weeks. The results elucidated that low-dose DEHP may cause the proliferation of the prostate with an increased PCNA/TUNEL ratio. Given the importance of estrogens and androgens in prostatic hyperplasia, our first objective was to evaluate the levels of sex hormones. DEHP improved the ratio of estradiol (E2)/testosterone (T) in a dose-dependent manner and upregulated estrogen receptor alpha (ERα) and androgen receptor (AR) expressions. Prostaglandin synthases, including cyclooxygenase-2 (COX-2) and lipocalin-type prostaglandin D synthase (L-PGDS), were significantly upregulated in the ventral prostate. COX-2 and L-PGDS might mediate the tendency of prostatic hyperplasia induced by low-dose DEHP through estradiol/androgen regulation and imbalance between proliferation and apoptosis in vivo. These findings provide the first evidence that prostaglandin synthases contribute to the tendency toward benign prostatic hyperplasia induced by DEHP. Further investigations will have to be performed to facilitate an improved understanding of the role of prostaglandin synthases in DEHP-induced prostatic lesions.

Lipocalin-Type Prostaglandin D2 Synthase Protein- A Central Player in Metabolism.

Lipocalin-type prostaglandin D synthase was previously known as ß-trace protein (BTP), a low-molecular-weight glycoprotein that is heavily expressed in human cerebrospinal fluid. Nevertheless, it is also seen to be expressed in numerous other tissues including the kidney, liver, lung, heart, adipose, muscle, and pancreas. Functionally, L-PGDS behaves like a lipocalin type protein where it helps in binding and transportation of small lipophilic substances, such as steroids, retinoids, and other lipophilic ligands. Enzymatically, L-PGDS functions as a prostaglandin synthase where it helps in the production of PGD2 by catalyzing the isomerization of PGH2, a common precursor of the two series of prostaglandins. PGD2 regulates its physiological function through two individual receptors named DP1 and DP2. L-PGDS has been a central player in many diseases, its role in metabolism including diabetes, fatty liver disease, and obesity has gathered a large attention. In this review, we summarize the current state of knowledge about L-PGDS and it's signaling in adipose, hepatic, skeletal muscle, and pancreas tissues, which are core targets for metabolic studies. Modulation of L-PGDS signaling can be considered as a potential future therapeutic target for the treatment of insulin resistance as well as fatty liver disease.