Anti-inflammatory effects of anethole in lipopolysaccharide-induced acute lung injury in mice

Aims

Anethole, the major component of the essential oil of star anise, has been reported to have antioxidant, antibacterial, antifungal, anti-inflammatory, and anesthetic properties. In this study, we investigated the anti-inflammatory effects of anethole in a mouse model of acute lung injury induced by lipopolysaccharide (LPS).

Main methods

BALB/C mice were intraperitoneally administered anethole (62.5, 125, 250, or 500 mg/kg) 1 h before intratracheal treatment with LPS (1.5 mg/kg) and sacrificed after 4 h. The anti-inflammatory effects of anethole were assessed by measuring total protein and cell levels and inflammatory mediator production and by histological evaluation and Western blot analysis.

Key findings

LPS significantly increased total protein levels; numbers of total cells, including macrophages and neutrophils; and the production of inflammatory mediators such as matrix metalloproteinase 9 (MMP-9), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nitric oxide (NO) in bronchoalveolar lavage fluid. Anethole (250 mg/kg) decreased total protein concentrations; numbers of inflammatory cells, including neutrophils and macrophages; and the inflammatory mediators MMP-9, TNF-α and NO. In addition, pretreatment with anethole decreased LPS-induced histopathological changes. The anti-inflammatory mechanism of anethole in LPS-induced acute lung injury was assessed by investigating the effects of anethole on NF-κB activation. Anethole suppressed the activation of NF-κB by blocking IκB-α degradation.

Significance

These results, showing that anethole prevents LPS-induced acute lung inflammation in mice, suggest that anethole may be therapeutically effective in inflammatory conditions in humans.     

Development of peptide inhibitor as a therapeutic agent against head and neck squamous cell carcinoma (HNSCC) targeting p38α MAP kinase

Background

The p38α MAP kinase pathway is involved in inflammation, cell differentiation, growth, apoptosis and production of pro-inflammatory cytokines TNF-α and IL-1β. The overproduction of these cytokines plays an important role in cancer. The aim of this work was to design a peptide inhibitor on the basis of structural information of the active site of p38α.

Methods

A tetrapeptide, VWCS as p38α inhibitor was designed on the basis of structural information of the ATP binding site by molecular modeling. The inhibition study of peptide with p38α was performed by ELISA, binding study by Surface Plasmon Resonance and anti-proliferative assays by MTT and flow cytometry.

Results

The percentage inhibition of designed VWCS against pure p38α protein and serum of HNSCC patients was 70.30 and 71.5%, respectively. The biochemical assay demonstrated the K_D and IC₅₀ of the selective peptide as 7.22 × 10^− 9 M and 20.08 nM, respectively. The VWCS as inhibitor significantly reduced viability of oral cancer KB cell line with an IC₅₀ value of 10 μM and induced apoptosis by activating Caspase 3 and 7.

Conclusions

VWCS efficiently interacted at the ATP binding pocket of p38α with high potency and can be used as a potent inhibitor in case of HNSCC.

General significance

VWCS can act as an anticancer agent as it potentially inhibits the cell growth and induces apoptosis in oral cancer cell-line in a dose as well as time dependent manner. Hence, p38α MAP kinase inhibitor can be a potential therapeutic agent for human oral cancer.     

C-type natriuretic peptide ameliorates ischemia/reperfusion-induced acute kidney injury by inhibiting apoptosis and oxidative stress in rats

Aims

Although atrial natriuretic peptide has been shown to attenuate ischemia–reperfusion (IR)-induced kidney injury, the effect of natriuretic peptide receptor (NPR)-B activation on IR-induced acute kidney injury is not well documented. The purpose of the present study was to identify the effect of C-type natriuretic peptide (CNP), a selective activator of NPR-B, on the IR-induced acute kidney injury and its mechanisms involved.

Main methods

Unilaterally nephrectomized rats were insulted by IR in their remnant kidney, and they were randomly divided into three groups: sham, vehicle + IR, and CNP + IR groups. CNP (0.2 μg/kg/min) was administered intravenously at the start of a 45-min renal ischemia for 2 h. Rats were then killed 24 h after I/R, and the blood and tissue samples were collected to assess renal function, histology, TUNEL assay, and Western blot analysis of kidney Bax and Bcl-2 expressions.

Key findings

The levels of blood urea nitrogen and serum creatinine were significantly increased in rats after IR compared with vehicle-treated rats. IR elevated apoptosis, Bcl-2/Bax ratio, TUNEL positivity, oxidative stress parameters, malondialdehyde concentration, and superoxide dismutase activity. IR also induced epithelial desquamation of the proximal tubules and glomerular shrinkage. CNP significantly attenuated the IR-induced increase in BUN and serum creatinine. Furthermore, CNP restored the suppressed renal cyclic guanosine 3′ 5′-monophosphate levels caused by IR insult.

Significance

Study findings suggest that CNP could ameliorate IR-induced acute kidney injury through inhibition of apoptotic and oxidative stress pathways, possibly through NPR-B-cGMP signaling.     

A single-nucleotide polymorphism in tumor necrosis factor-α (− 308 G/A) as a biomarker in chronic pancreatitis

Objective

Chronic pancreatitis is a gradual, long-term inflammation of the pancreas that results in alteration of its normal structure and function. The study aims to investigate the role of − 308 (G/A) polymorphism of TNF-α gene in chronic pancreatitis.

Material and methods

A total of 200 subjects were included in this case–control study. A total of 100 in patients admitted in the Gastroenterology Unit of Gandhi Hospital and Osmania General Hospital, Hyderabad were included in the present study. An equal number of healthy control subjects were randomly selected for the study. The genotyping of TNF-α gene was carried out by tetra-primer ARMS PCR followed by gel electrophoresis. The TNF-α levels were assayed by enzyme-linked immunosorbent assay.

Results

A significant variation with respect to the genotypic and allelic distribution in the disease group when compared to control subjects [OR = 2.001 (1.33–3.005), p < 0.0001**] was observed. Subjects homozygous for the A allele had higher TNF-α levels compared to G allele.

Conclusion

The present study revealed a significant association of the TNF-α gene promoter polymorphism with chronic pancreatitis. Thus, TNF-α genotype can be considered as one of the biological markers in the etiology of chronic pancreatitis.     

Structural alterations in Pseudomonas aeruginosa by zingerone contribute to enhanced susceptibility to antibiotics,serum and phagocytes

Aims

Excessive use of antibiotics has led to evolutionary adaptation resulting in emergence of multidrug resistance in P. aeruginosa. The aim of the present study was oriented towards exploiting zingerone (active component of ginger) in making P. aeruginosa more susceptible to killing with antibiotics, humoral/cellular defences and studying its underlying mechanism.

Main method

Effect of zingerone treatment on antibiotic susceptibility, serum, and phagocytic killing of P. aeruginosa was studied. The underlying mechanism was evaluated in terms of cell surface hydrophobicity, alginate and LPS production. TNF-α and MIP-2 cytokine production by mouse macrophages was also checked. Structural analysis was carried out using scanning electron microscopy (SEM) and liquid chromatography-mass spectrometry (LC-MS) analysis.

Key findings

Zingerone treated cells showed increased susceptibility to variety of antibiotics, serum as well as macrophages (p < 0.05). Zingerone treatment significantly reduced cell surface hydrophobicity, alginate and LPS production (p < 0.05). Zingerone treated cells showed significant decrease in TNF-α and MIP-2 cytokine production as compared to non-treated cells. Coupled with this, reduction in the production of extracellular protective matrix and modulation of chemical structure of LPS was also observed by scanning electron microscopy and liquid chromatography-mass spectrometric (LC-MS) respectively. Zingerone significantly influence surface structure of P. aeruginosa which contributes towards enhanced susceptibility to antibiotics and innate immune system.

Significance

Use of phytochemicals may prove to be a novel therapeutic approach by enhancing susceptibility of pathogenic microorganisms to antibiotics and immune system. Zingerone has proved to be one such agent which can be employed as a potential anti-virulent drug candidate against P. aeruginosa infections.     

Hepcidin expression by human monocytes in response to adhesion and pro-inflammatory cytokines

Background

A previous urine proteomic analysis from our laboratory suggested that hepcidin may be a biomarker for lupus nephritis flare. Immunohistochemical staining of kidney biopsies from lupus patients showed that hepcidin was expressed by infiltrating renal leukocytes. Here we investigated whether inflammatory cytokines relevant to the pathogenesis of lupus nephritis and other glomerular diseases regulate hepcidin expression by human monocytes.

Methods

Human CD14+ monocytes were incubated with interferon alpha (IFNα), interferon gamma (IFNγ), interleukin-6 (IL6), interleukin-1 beta (IL1β), monocyte chemotactic factor-1 (MCP1), or tumor necrosis factor alpha (TNFα). Hepcidin expression was examined by real-time PCR and enzyme immunoassay.

Results

Monocyte hepcidin mRNA increased during adherence to the tissue culture wells, reaching a level 150-fold higher than baseline within 12 h of plating. After accounting for the effects of adhesion, monocytes showed time and dose-dependent up-regulation of hepcidin mRNA upon treatment with IFNα or IL6. One hour of incubation with IFNα or IL6 increased hepcidin mRNA 20 and 80-fold, respectively; by 24 h the mRNA remained 5- and 2.4-fold higher than baseline. IL1β, IFNγ, and MCP-1 did not affect monocyte hepcidin expression. TNFα inhibited hepcidin induction by IL6 in monocytes by 44%. After 24 h of treatment with IFNα or IL6, immunoreactive hepcidin production by monocytes increased 3- and 2.6-fold, respectively.

Conclusion

Human monocytes produce hepcidin in response to adhesion and the pro-inflammatory cytokines IFNα and IL6.

General significance

The appearance of hepcidin in the kidneys or urine during glomerular diseases may be from infiltrating monocytes induced to express hepcidin by adherence and exposure to pro-inflammatory cytokines found in the renal milieu.     

Synergistic effect of anti and pro-inflammatory cytokine genes and their promoter polymorphism with ST-elevation of myocardial infarction

Background

The single-gene approach in association studies of polygenic diseases such as acute myocardial infarction (AMI) is likely to provide limited value. Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) plasma levels may be genetically influenced.

Aim

We evaluate the impact of single nucleotide polymorphism of the promoter region of these genes, as well as reciprocal interaction of these genes with ST-elevation of myocardial infarction (STEMI).

Methods

In a case–control study 500 STEMI patients and 500 age- and sex-matched controls were studied. Three single-nucleotide polymorphism genotypes were evaluated by polymerase chain reaction and restriction enzyme analysis and assessed their association with STEMI. The synergistic effects of IL-6, TNF-α and IL-10 gene polymorphisms were evaluated by using logistic regression analysis.

Results

We found that IL-6 and TNF-α concentrations of studied population were significantly different (p < 0.0001) in each genotype of IL-6 − 174G>C and TNF-α − 308G>A gene polymorphisms respectively. A significant association was found in multivariate analysis for the IL-6 − 174G>C [odds ratio (OR): 0.390; 95% confidence interval (CI): 0.176–0.865, p = 0.020] and TNF-α − 308G>A [OR: 0.372; 95% CI: 0.171–808, p = 0.012] gene polymorphisms with STEMI. In contrast, IL-10 − 592C>A gene polymorphism was no longer significant in the multivariate model (OR: 0.678; 95% CI: 0.288 to 1.594, p = 0.373) whereas significant in univariate analysis (OR: 0.697; 95% CI: 0.523–0.929, p = 0.014).

Conclusions

Our findings suggest that IL-6, TNF-α and IL-10 gene polymorphisms all contribute in the association with STEMI whereas the association persisted only for IL-6 and TNF-α but not for IL-10 gene polymorphism with this disease in the multivariate analysis.     

Expression of the 78 kD glucose-regulated protein is induced by endoplasmic reticulum stress in the development of hepatopulmonary syndrome

Objective

This study is to explore the role of 78 kD glucose-regulated protein (GRP78) in the development of hepatopulmonary syndrome (HPS) in rats.

Methods

The rat model of liver cirrhosis and HPS were induced with multiple pathogenic factors. Hematoxylin and eosin (H & E) staining was performed to detect the pathological changes of the lung and liver tissues. The levels of alanine transferase (ALT), endotoxin, and tumor necrosis factor-α (TNF-α) in plasma and TNF-α and malondialdehyde (MDA) in lung tissues were detected. RT-PCR and Western blotting were conducted to detect the mRNA and protein expression levels of GRP78 in lungs.

Results

The plasma endotoxin level was gradually increased as HPS developed, and the mRNA and protein expression levels of GRP78 in lungs were also increased as the disease progressed. The levels of ALT and TNF-α in plasma and the contents of TNF-α and MDA in lung tissues were gradually increased along with the disease progression, with a strong positive correlation. Compared with controls, the plasma TNF-α level and the mRNA and protein expression levels of GRP78 in lung tissues were significantly higher in rats with HPS. The levels of endotoxin and ALT in plasma and the level of MDA in lungs were significantly higher in rats with HPS than controls.

Conclusions

The increased GRP78 expression is indicative of endoplasmic reticulum stress response during HPS, which may play an important role in the disease pathogenesis.     

Anti-inflammatory effect of pyroglutamyl-leucine on lipopolysaccharide-stimulated RAW 264.7 macrophages

Aims

Food-derived peptides have been reported to yield a variety of health promoting activities. Pyroglutamyl peptides are contained in the wheat gluten hydrolysate. In the present study, we investigated the effect of pyroglutamyl dipeptides on the lipopolysaccharide (LPS)-induced inflammation in macrophages.

Main methods

RAW 264.7 macrophages were treated with LPS and various concentrations of pyroglutamyl-leucine (pyroGlu-Leu), -valine (pyroGlu-Val), -methionine (pyroGlu-Met), and -phenylalanine (pyroGlu-Phe). Cell viability/proliferation and various inflammatory parameters were measured by the established methods including ELISA and western blotting. The binding of fluorescein isothiocyanate-labeled LPS to RAW 264.7 cells was also measured fluorescently.

Key findings

All the tested dipeptides significantly inhibited the secretion of nitric oxide, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 from LPS-stimulated RAW 264.7 macrophages. Above all, pyroGlu-Leu inhibited the secretion of all these inflammatory mediators even at the lowest dose (200 μg/ml). PyroGlu-Leu dose-dependently suppressed IκBα degradation and MAPK (JNK, ERK, and p38) phosphorylation in LPS-stimulated RAW 264.7 cells. On the other hand, it did not affect the binding of LPS to the cell surface.

Significance

Our results indicated that pyroGlu-Leu inhibits LPS-induced inflammatory response via the blocking of NF-κB and MAPK pathways in RAW 264.7 macrophages.     

Optimal conditions of LDR to protect the kidney from diabetes: Exposure to 12.5 mGy X-rays for 8 weeks efficiently protects the kidney from diabetes

Aims

We reported the attenuation of diabetes-induced renal dysfunction by exposure to multiple low-dose radiation (LDR) at 25 mGy every other day by suppressing renal oxidative damage. We here explored the optimal conditions of LDR to protect the kidney from diabetes.

Main methods

Male C57BL/6J mice with type 1 diabetes were induced with multiple injections of low-dose streptozotocin. Diabetic mice received whole body X-irradiation at a dose of 12.5, 25 or 50 mGy every other day for either 4 or 8 weeks. Age-matched normal mice were similarly irradiated at the dose of 25 mGy for 4 or 8 weeks. The renal function and histopathological changes were examined at the 4th and 8th weeks of the study.

Key findings

Diabetes induced renal dysfunction is shown by the decreased creatinine and increased microalbumin in the urine. Renal oxidative damage, detected by protein nitration and lipid oxidation, and remodeling, reflected by increased expression of connective tissue growth factor, collagen IV and fibronectin, were significantly increased in diabetic mice. All these renal pathological and function changes in diabetic mice were significantly attenuated by exposure to LDR at all regimens, among which, however, exposure to LDR at 12.5 mGy for 8 weeks provided the best protective effect on the kidney of diabetic mice.

Significance

Our results suggest that whole-body LDR at 12.5 mGy every other day for 8 weeks is the optimal condition of LDR to protect the kidney from diabetes.     

α-Crystallin protects RGC survival and inhibits microglial activation after optic nerve crush

Aims

Activation of retinal microglial cells (RMCs) is known to contribute to retinal ganglion cell (RGC) death after optic nerve injury. The purpose of this study was to investigate the effects of intravenous injection of α-crystallin on RGC survival and RMC activation in a rat model of optic nerve crush.

Main methods

RGCs were retrogradely labeled with fluorogold. Rats were intravenously injected with normal saline or α-crystallin (0.05 g/kg, 0.5 g/kg, and 5 g/kg) at 2, 4, 6, 8, 10, and 12 days after the optic nerve crush. Activated RMCs were characterized using immunofluorescence labeling with CD11b, and TNF-α and iNOS expression was detected using immunoblot analyses. We analyzed the morphology and numbers of RGC and RMC 2 and 4 weeks after injury using fluorescence and confocal microscopy.

Key findings

The number of RGCs decreased after optic nerve injury, accompanied by significantly increased numbers of activated RMCs. Intravenous injection of α-crystallin decreased the number of RMCs, and enhanced the number of RGCs compared to saline injection. α-Crystallin administration inhibited TNF-α and iNOS protein expression induced by optic nerve injury.

Significance

Our results suggest that α-crystallin promotes RGC survival and inhibits RMC activation. Intravenous injection of α-crystallin could be a possible strategy for the treatment of optic nerve injury.     

Antinociceptive,anti-inflammatory and antipyretic effects of 1.5-diphenyl-1H-Pyrazole-3-carbohydrazide,a new heterocyclic pyrazole derivative

Aims

Heterocyclic pyrazole derivative has been described for the treatment of pain and inflammatory diseases. This study evaluated the in vivo, antinociceptive, anti-inflammatory and antipyretic effects of 1.5-diphenyl-1H-Pyrazole-3-carbohydrazide (1.5-DHP) and the in vivo or in vitro mechanism of action.

Main methods

Acetic acid-induced writhing, hot-plate and formalin-induced nociception tests were used to evaluate the antinociceptive effect, while the rota-rod test was used to assess the motor activity. Croton oil-induced ear edema and carrageenan-induced peritonitis tests were used to investigate the anti-inflammatory effect of 1.5-DHP. The antipyretic effect was assessed using the LPS-induced fever model. The mechanism of action was evaluated by PGE₂ and TNF-α measurement and cyclooxygenase inhibition assay.

Key findings

Oral administration (p.o.) of 1.5-DHP (1, 3, 10 mg/kg) caused a dose-related inhibition of the acetic acid-induced writhing, however the highest dose was not effective on the hot-plate and rota-rod. In the formalin-induced nociception, 1.5-DHP (10 mg/kg, p.o.) inhibited only the late phase of nociception. This same dose of 1.5-DHP also reduced the croton oil-induced ear edema. 1.5-DHP (3, 10, 30 mg/kg, p.o.) produced a dose-related reduction of leukocyte migration on the carrageenan-induced peritonitis. 1.5-DHP (60 mg/kg, p.o.) reduced the fever and the increase of PGE₂ concentration in the cerebrospinal fluid induced by LPS. 1.5-DHP inhibited both COXs in vitro. Finally, 1.5-DHP (10 mg/kg, p.o.) reduced the TNF-α concentration in peritoneal exudates after carrageenan injection.

Significance

These results indicate that 1.5-DHP produces anti-inflammatory, antinociceptive and antipyretic effects by PGE₂ synthesis reduction through COX-1/COX-2 inhibition and by TNF-α synthesis/release inhibition.     

Renoprotective effect of paricalcitol via a modulation of the TLR4-NF-κB pathway in ischemia/reperfusion-induced acute kidney injury

Background

The pathophysiology of ischemic acute kidney injury (AKI) is thought to include a complex interplay between vascular endothelial cell dysfunction, inflammation, and tubular cell damage. Several lines of evidence suggest a potential anti-inflammatory effect of vitamin D in various kidney injury models. In this study, we investigated the effect of paricalcitol, a synthetic vitamin D analog, on renal inflammation in a mouse model of ischemia/reperfusion (I/R) induced acute kidney injury (AKI).

Methods

Paricalcitol was administered via intraperitoneal (IP) injection at 24 h before ischemia, and then I/R was performed through bilateral clamping of the renal pedicles. Twenty-four hours after I/R, mice were sacrificed for the evaluation of injury and inflammation. Additionally, an in vitro experiment using HK-2 cells was also performed to examine the direct effect of paricalcitol on tubular cells.

Results

Pre-treatment with paricalcitol attenuated functional deterioration and histological damage in I/R induced AKI, and significantly decreased tissue neutrophil and macrophage infiltration and the levels of chemokines, the pro-inflammatory cytokine interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1). It also decreased IR-induced upregulation of Toll-like receptor 4 (TLR4), and nuclear translocation of p65 subunit of NF-κB. Results from the in vitro study showed pre-treatment with paricalcitol suppressed the TNF-α-induced depletion of cytosolic IκB in HK-2 cells.

Conclusion

These results demonstrate that pre-treatment with paricalcitol has a renoprotective effect in ischemic AKI, possibly by suppressing TLR4-NF-κB mediated inflammation.     

Peritoneal mast cell degranulation differently affected thioglycollate-induced macrophage phenotype and activity in Dark Agouti and Albino Oxford rats

Aims

Macrophages are heterogeneous population of inflammatory cells and, in response to the microenvironment, become differentially activated. The objective of the study was to explore macrophage effector functions during different inflammatory conditions in two rat strains.

Main methods

We have investigated the effects of in vivo treatment with mast cell-degranulating compound 48/80 and/or thioglycollate on peritoneal macrophage phagocytosis and capacity to secrete hydrogen peroxide (H₂O₂), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) in Dark Agouti (DA) and Albino Oxford (AO) rat strains. Besides, fresh peritoneal cells were examined for the expression of ED1, ED2 and CD86 molecules.

Key findings

In thioglycollate-elicited macrophages, increased proportion of ED1 + cells was accompanied with elevated phagocytosis of zymosan (DA strain), whereas increased expression level of CD86 molecule on ED2 + macrophages matched elevated secretory capacity for H₂O₂, TNF-α and NO (AO rats). Although mast cell degranulation induced by compound 48/80 increased the percentages of ED2 + macrophages in both rat strains, the proportion of ED2 + cells expressing CD86 molecule was decreased and increased in DA and AO rats, respectively. Furthermore, in DA strain compound 48/80 diminished macrophage secretion of NO, but stimulated all macrophage functions tested in AO strain. If applied concomitantly, the compound 48/80 additively increased macrophage activity induced by thioglycollate in AO rats.

Significance

Macrophages from DA and AO rat strains show different susceptibility to mediators released from mast cells, suggesting that strain-dependant predisposition(s) toward particular activation pattern is decisive for the macrophage efficacy in response to inflammatory agents.     

Degraded λ-carrageenan activates NF-κB and AP-1 pathways in macrophages and enhances LPS-induced TNF-α secretion through AP-1

Background

Carrageenan (CGN), a high molecular weight sulfated polysaccharide, is a traditional ingredient used in food industry. Its degraded forms have been identified as potential carcinogens, although the mechanism remains unclear.

Methods

The effects of degraded λ-carrageenan (λ-dCGN) on murine RAW264.7 cells and human THP-1-derived macrophage cells were investigated by studying its actions on tumor necrosis factor alpha (TNF-α) secretion, Toll-like receptor 4 (TLR4) expression, and activation of nuclear factor-κb (NF-κB) and activation protein-1 (AP-1) pathways.

Results

We found that λ-dCGN was much stronger than native λ-CGN in the activation of macrophages to secrete TNF-α. Treatment of RAW264.7 cells with λ-dCGN resulted in the upregulation of TLR4, CD14 and MD-2 expressions, but it did not increase the binding of lipopolysacchride (LPS) with macrophages. Meanwhile, λ-dCGN treatment activated NF-κB via B-cell lymphoma/leukemia 10 (Bcl10) and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) phosphorylation. In addition, λ-dCGN induced extracellular signal-regulated kinases/1/2/mitogen-activated protein kinases (ERK1/2/MAPK) and AP-1 activation. Interestingly, pretreatment of RAW264.7 cells with λ-dCGN markedly enhanced LPS-stimulated TNF-α secretion. This pretreatment resulted in the enhanced phosphorylation of ERK1/2 and c-Jun N-terminal kinase (JNK) and intensified activation of AP-1.

Conclusions

λ-dCGN induced an inflammatory reaction via both NF-κB and AP-1, and enhanced the inflammatory effect of LPS through AP-1 activation.

General significance

The study demonstrated the role of λ-dCGN to induce the inflammatory reaction and to aggravate the effect of LPS on macrophages, suggesting that λ-dCGN produced during food processing and gastric digestion may be a safety concern.     

Predictive ability of circulating osteoprotegerin as a novel biomarker for early detection of acute kidney injury induced by sepsis

Background

Though significant progress has been made towards new diagnostic approaches for early detection of acute kidney injury (AKI) induced by different factors, there is still an urgent demand for a more specific and predictive biomarker for each type. The aim of this study is to unravel the potential diagnostic utility of circulating osteoprotegerin (OPG) in septic patients who developed AKI in the ICU, compared to cystatin C (a renal function maker) and KIM-1 (a kidney damage marker).

Methods

Eighty patients (male = 43, female = 37) with ages ranging from 42 to 46 years and with sepsis, 40 of whom developed AKI, and 30 healthy controls were enrolled in this prospective study.

Results

Results revealed significant progressive elevation of OPG, along with cystatinCand KIM-1, among sepsis, severe sepsis, and sepsis-AKI patients. The progression of OPG levels paralleled the deterioration of kidney and endothelial functions from sepsis to sepsis-AKI, revealed as progressively increased levels of serum Eselectin (15.3%), endothelin-1 (ET-1) (19.6%), and decreased nitric oxide (NO) (29.7%), associated with elevations of TNF-α (25.5%) and TGF-β (18%). Their comparative prognostic validity of sepsis-AKI was assessed using ROC analysis, which revealed that OPG, KIM-1, and cystatin C showed similar AUCs (0.827-0.83) but with different sensitivities, viz., 84%, 88%, and 92%, respectively. Although cystatin showed 82% specificity, OPG showed a higher, similar specificity to KIM-1 of 85%, indicating its potential function as a marker of renal damage such as KIM-1.

Conclusion

This study revealed a significant elevation of circulating OPG in septic patients with different levels of severity and those who progressed to AKI. Moreover, OPG showed a significant correlation to KIM-1 and cystatin, as well as conventional renal, inflammatory, and endothelial markers. Having a similar specificity to KIM-1, as evidenced by the ROC analysis, OPG has the potential to serve as a reliable biomarker of kidney damage in cases of sepsis-AKI.

     

miRNA-1 regulates endothelin-1 in diabetes

Aims

MicroRNAs (miRNAs) play important roles in several biological processes. In this study, we investigated the role of miR-1, an endothelin-1 (ET-1) targeting miRNA, in endothelial cells (ECs) and tissues of diabetic animals. ET-1 is known to be of pathogenetic significance in several chronic diabetic complications.

Main methods

PCR array was used to identify alterations of miRNA expression in ECs exposed to glucose. miR-1 expression was validated by TaqMan real-time PCR assay. Human retinal ECs (HRECs) and human umbilical vein ECs (HUVECs) exposed to various glucose levels with or without miR-1 mimic transfection, and tissues from streptozotocin-induced diabetic animals after two months of follow-up, were examined for miR-1 expression, as well as ET-1 and fibronectin (FN) mRNA and protein levels.

Key findings

Array analyses showed glucose-induced alterations of 125 miRNAs (out of 381) in ECs exposed to 25 mM glucose compared to 5 mM glucose. Fifty-one miRNAs were upregulated and 74 were downregulated. 25 mM glucose decreased miR-1 expression and increased ET-1 mRNA and protein levels. miR-1 mimic transfection prevented HG-induced ET-1 upregulation. Furthermore, glucose induced upregulation of FN, which is mediated partly by ET-1, was also prevented by such transfection.Diabetic animals showed decreased miR-1 expression in the retina, heart and kidneys. In parallel, ET-1 mRNA expressions were increased in these tissues of diabetic animals, in association with upregulation of FN.

Significance

These results indicate a novel glucose-induced mechanism of tissue damage, in which miR-1 regulates ET-1 expressions in diabetes. Identifying such mechanisms may lead to RNA based treatment for diabetic complications.