Retinal microglial activation and inflammation induced by amadori-glycated albumin in a rat model of diabetes

OBJECTIVE

During diabetes, retinal microglial cells are activated to release inflammatory cytokines that initiate neuronal loss and blood-retinal barrier breakdown seen in diabetic retinopathy (DR). The mechanism by which diabetes activates microglia to release those inflammatory mediators is unclear and was therefore elucidated.

RESEARCH DESIGN AND METHODS

Microglia activation was characterized in streptozocin-injected rats and in isolated microglial cells using immunofluorescence, enzyme-linked immunosorbent assay, RT-PCR, and Western blot analyses.

RESULTS

In 8-week diabetic retina, phospho-extracellular signal-related kinase (ERK) and P38 mitogen-activated protein kinases were localized in microglia, but not in Mueller cells or astrocytes. At the same time, Amadori-glycated albumin (AGA)-like epitopes were featured in the regions of microglia distribution, implicating a pathogenic effect on microglial activation. To test this, diabetic rats were treated intravitreally with A717, a specific AGA-neutralizing antibody, or murine IgG. Relative to nondiabetic rats, diabetic rats (IgG-treated) manifested 3.9- and 7.9-fold increases in Iba-1 and tumor necrosis factor (TNF)-α mRNAs, respectively. Treatment of diabetic rats with A717 significantly attenuated overexpression of these mRNAs. Intravitreal injection of AGA per se in normal rats resulted in increases of Iba-1 expression and TNF-α release. Guided by these results, a cultured retinal microglia model was developed to study microglial response after AGA treatment and the mechanistic basis behind this response. The results showed that formation of reactive oxygen species and subsequent activation of ERK and P38, but not Jun NH2-terminal kinase, are molecular events underpinning retinal microglial TNF-α release during AGA treatment.

CONCLUSIONS

These results provide new insights in understanding the pathogenesis of early DR, showing that the accumulated AGA within the diabetic retina elicits the microglial activation and secretion of TNF-α. Thus, intervention trials with agents that neutralize AGA effects may emerge as a new therapeutic approach to modulate early pathologic pathways long before the occurrence of vision loss among patients with diabetes.

Cepharanthine and Piperine ameliorate diabetic nephropathy in rats: role of NF-κB and NLRP3 inflammasome

AIMS

Hyperglycemia leads to elevation of oxidative stress and proinflammatory cytokines which are the main causes of diabetic nephropathy (DN). NLRP3 inflammasome and thioredoxin-interacting protein (TXNIP) are recently assumed to participate in the development of DN. We aimed to investigate the effects of Cepharanthine (CEP), Piperine (Pip) and their combination in streptozotocin (STZ)-induced DN focusing on their role to modulate NLRP3 and TXNIP induced inflammation.

MAIN METHODS

Diabetic rats were treated with intraperitoneal (i.p.) injection of CEP (10mg/kg/day), Pip (30mg/kg/day) or their combination for 8weeks. Nuclear factor kappa B (NF-κB), tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) were assessed by ELISA technique. TXNIP and NLRP3 genes expressions were evaluated by real time-PCR.

KEY FINDINGS

Diabetic rats showed significant increase in renal TXNIP and NLRP3 expression. CEP, Pip or their combination significantly decreased TXNIP and NLRP3 expression in diabetic kidneys. Hyperglycemia induced NF-κB activation leading to increased IL-1β and TNF-α levels. CEP, Pip or their combination showed significant inhibition of NF-κB together with decreased IL-1β and TNF-α levels in diabetic rats. Also, diabetic rats showed significant decrease in creatinine clearance and increase in blood glucose, serum creatinine, blood urea nitrogen, malondialdehyde, proteinuria, and kidney weight to body Weight ratio. All of these changes were reversed by CEP, Pip or their combination.

SIGNIFICANCE

The antioxidant and anti-inflammatory effects of CEP and Pip which were accompanied by inhibition of NF-κB and NLRP3 activation might be helpful mechanisms to halt the progression of DN.

A(₂A) adenosine receptor (A(₂A)AR) as a therapeutic target in diabetic retinopathy

In diabetic retinopathy (DR), abnormalities in vascular and neuronal function are closely related to the local production of inflammatory mediators whose potential source is microglia. A(₂A) adenosine receptor (A(₂A)AR) has been shown to possess anti-inflammatory properties that have not been studied in DR. Here, we evaluate the role of A(₂A)AR and its underlying signaling in retinal complications associated with diabetes. Initial studies in wild-type mice revealed that the treatment with the A(₂A)AR agonist resulted in marked decreases in hyperglycemia-induced retinal cell death and tumor necrosis factor (TNF)-α release. To further assess the role of A(₂A)AR in DR, we studied the effects of A(₂A)AR ablation on diabetes-induced retinal abnormalities. Diabetic A(₂A)AR(-/-) mice had significantly more terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells, TNF-α release, and intercellular adhesion molecule-1 expression compared with diabetic wild-type mice. To explore a potential mechanism by which A(₂A)AR signaling regulates inflammation in DR, we performed additional studies using microglial cells treated with Amadori-glycated albumin, a risk factor in diabetic disorders. The results showed that activation of A(₂A)AR attenuated Amadori-glycated albumin-induced TNF-α release in a cAMP/exchange protein directly activated by cAMP-dependent mechanism and significantly repressed the inflammatory cascade, C-Raf/extracellular signal-regulated kinase (ERK), in activated microglia. Collectively, this work provides pharmacological and genetic evidence for A(₂A)AR signaling as a control point of cell death in DR and suggests that the retinal protective effect of A(2A)AR is mediated by abrogating the inflammatory response that occurs in microglia via interaction with C-Raf/ERK pathway.

Glycyrrhizin ameliorates high fat diet-induced obesity in rats by activating NrF2 pathway

AIM

Obesity based on insulin resistance is a state of chronic oxidative stress and inflammation that are highly regulated through nuclear factor Erythroid 2-related factor 2 (NrF2) pathway.

MATERIALS AND METHODS

70 male Wistar rats were randomized into two models. The prophylactic model was 10weeks and rats were grouped into: normal group, GL group (received glycyrrhizin 50mg/kg/day orally along with normal pellet diet), HFD group and HFD+ GL group (received glycyrrhizin along with HFD). The treatment model was 14weeks and rats were grouped into: normal group, HFD group and HFD+GL group (received glycyrrhizin from the week 10).

KEY FINDINGS

Glycyrrhizin decreased significantly rat weights and insulin resistance, normalized lipid profile and reduced significantly the adipocytes size in adipose tissue and lipid deposition in the liver tissue through histopathologic examination. Furthermore, glycyrrhizin ameliorated obesity-induced oxidative stress which indicated by significant decrease in liver malondialdehyde level (P<0.001) and increase in the total antioxidant capacity (P<0.001). Interestingly, molecular mechanism of glycyrrhizin was explored, that included significant reduction of liver gluconeogenic enzymes mRNA expression (P<0.001), a significant increase of liver insulin receptor, NrF2 and homooxygenase-1 mRNA expressions (P<0.001) and significant increase and nuclear translocation of NrF2 in liver tissue.

SIGNIFICANCE

Glycyrrhizin ameliorates HFD-induced obesity in rats that may be attributed to its ability to increase insulin receptor expression and to activate NrF2 and subsequent homooxygenase-1 pathway. Thus, this work represents a safe natural compound (glycyrrhizin) that has a great role either as prophylaxis or treatment for insulin resistance related to obesity.

Protective effects of L-carnosine on CCl4 -induced hepatic injury in rats

The present study was undertaken to investigate the possible protective effect of L-carnosine (CAR), an endogenous dipeptide of alanine and histidine, on carbon tetrachloride (CCl4)-induced hepatic injury. Liver injury was induced in male Sprague-Dawley rats by intraperitoneal (i.p.) injections of CCl4, twice weekly for six weeks. CAR was administered to rats daily, at dose of 250 mg/kg, i.p. At the end of six weeks, blood and liver tissue specimens were collected. Results show that CAR treatment attenuated the hepatic morphological changes, necroinflammation and fibrosis induced by CCl4, as indicated by hepatic histopathology scoring. In addition, CAR treatment significantly reduced the CCl4-induced elevation of liver-injury parameters in serum. CAR treatment also combatted oxidative stress; possibly by restoring hepatic nuclear factor erythroid 2-related factor 2 (Nrf-2) levels. Moreover, CAR treatment prevented the activation of hepatic stellate cells (HSCs), as indicated by reduced α-smooth muscle actin (α-SMA) expression in the liver, and decreased hepatic inflammation as demonstrated by a reduction in hepatic tumor necrosis factor-α (TNF-α) and restoration of interleukin-10 (IL-10) levels. In conclusion, CCl4-induced hepatic injury was alleviated by CAR treatment. The results suggest that these beneficial, protective effects are due, at least in part, to its anti-oxidant, anti-inflammatory and anti-fibrotic activities.

Relevance of serum levels of interleukin-6 and syndecan-1 in patients with hepatocellular carcinoma

Syndecan-1 is a trans-membrane heparan sulfate proteoglycan that localizes in epithelial cells and has been shown to be present in normal hepatocytes. It is thought to be involved in processes such as cell growth, differentiation and adhesion. However, the clinical data regarding syndecan-1 in patients with hepatocellular carcinoma (HCC) are scarce and controversial. Therefore, we need to evaluate the effects of HCC on the serum levels of syndecan-1. Thus, 40 patients with HCC and 31 patients with liver cirrhosis were physically examined. Blood samples were taken for measurements of routine markers (sGPT, sGOT, bilirubin, albumin, and α-fetoprotein), as well as serum levels of interleukin (IL)-6 and syndecan-1. Patients with liver cirrhosis showed significant increase in serum IL-6 as compared with HCC patients and the control subjects. Serum level of syndecan-1 was significantly increased in HCC patients as compared with the cirrhotic and control groups. In addition, significant positive correlations between syndecan-1 and serum levels of ALT, AST in HCC patients were found. Moreover, syndecan-1 increased significantly with increasing stage of Barcelona-Clinic Liver Cancer Group diagnostic and treatment strategy. In conclusion, the development of HCC is accompanied by a significant elevation in serum syndecan-1 levels. The increase in serum syndecan-1 may be linked with progression of HCC.

Hepatoprotective and anti-tumor effects of targeting MMP-9 in hepatocellular carcinoma and its relation to vascular invasion markers

The current study aims to evaluate the hepatoprotective and antitumor efficacy of doxycycline, as an matrix metalloproteases-9 (MMP-9) inhibitor, in an in vivo model of hepatocellular carcinoma (HCC). HCC was induced experimentally by thiocetamide (200 mg/kg) in rats that were treated with doxycycline (5 mg/kg for 16 weeks). Tumor severity was evaluated by measuring α-fetoprotein (AFP) levels, histopathologically by investigating liver sections stained with hematoxylin/eosin and assessing the survival rate. Liver homogenates were used for the measurements of MMP-9, fascin and hepatic heparan sulfate proteoglycan (HSPG) levels. Oxidative stress markers [malonaldehyde (MDA) and glutathione] as well as fibroblast growth factor-2 (FGF-2) gene expression were also among the assessed indicators. HCC in human and animal samples showed significant elevation in the levels of MMP-9 (231.7, 90 %), fascin (33.17, 140 %), as well as FGF-2 gene expression (342 % in animal samples; all respectively), associated with a significant decrease in hepatic HSPG level. Treatment of rats with doxycycline increased the animal survival rate (90 %) and decreased serum AFP level. Moreover, doxycycline ameliorated fibrosis and the induced massive hepatic tissue breakdown. It also restored the integrity of hepatic HSPGs and showed a magnificent inhibitory effect of tumor invasion cascade by significantly reducing the activities of MMP-9 (42 %) and fascin (50 %), as well as reducing the gene expression of FGF-2 (85.7 %). Furthermore, the antioxidant impact of doxycycline was evidenced by the significant elevation in glutathione level and depressing MDA level. To this end, doxycycline, proved promising hepatoprotective and antitumor activity and opens, thereby, a new horizon against vascular migration ability of the tumor cells.

ABT-702, an adenosine kinase inhibitor, attenuates inflammation in diabetic retinopathy

AIMS

This study was undertaken to determine the effect of an adenosine kinase inhibitor (AKI) in diabetic retinopathy (DR). We have shown previously that adenosine signaling via A2A receptors (A2AAR) is involved in retinal protection from diabetes-induced inflammation. Here we demonstrate that AKI-enhanced adenosine signaling provides protection from DR in mice.

MAIN METHODS

We targeted AK, the key enzyme in adenosine metabolism, using a treatment regime with the selective AKI, ABT-702 (1.5mg/kg intraperitoneally twice a week) commencing at the beginning of streptozotocin-induced diabetes at the age of eight weeks. This treatment, previously demonstrated to increase free adenosine levels in vivo, was maintained until the age of 16 weeks. Retinal inflammation was evaluated using Western blot, Real-Time PCR and immuno-staining analyses. Role of A2AAR signaling in the anti-inflammation effect of ABT-702 was analyzed in Amadori-glycated-albumin (AGA)-treated microglial cells.

KEY FINDINGS

At 16 weeks, when diabetic mice exhibit significant signs of retinal inflammation including up-regulation of oxidative/nitrosative stress, A2AAR, ENT1, Iba1, TNF-α, ICAM1, retinal cell death, and down-regulation of AK, the ABT-702 treated group showed lower signs of inflammation compared to control animals receiving the vehicle. The involvement of adenosine signaling in the anti-inflammation effect of ABT-702 was supported by the TNF-α release blocking effect of A2AAR antagonist in AGA-treated microglial cells.

SIGNIFICANCE

These results suggest a role for AK in regulating adenosine receptor signaling in the retina. Inhibition of AK potentially amplifies the therapeutic effects of site- and event-specific accumulation of extracellular adenosine, which is of highly translational impact.

Hepatoprotective effect of hesperidin in hepatocellular carcinoma: Involvement of Wnt signaling pathways

AIMS

Wnt3a and Wnt5a are ligands orchestrating the canonical and non-canonical pathways, respectively, with involvement in hepatocellular carcinoma (HCC). Hesperidin (HP) is a natural product found in citrus fruits and reputed for its antitumor activity. The present study aims to investigate the potential hepatoprotective effect of HP against thioacetamide (TAA)-induced HCC focusing on its potential role on Wnt3a and Wnt5a signaling pathways.

MAIN METHODS

Forty rats were equally divided into groups; normal control, HP control (receiving HP, 150mg/kg/day), HCC (receiving TAA, 200mg/kg twice weekly for 14weeks) and HP-HCC (receiving HP and TAA). Gene expressions of Wnt3a, Wnt5a, β-catenin and Cyclin D1 were assessed by qPCR, while their protein levels, along with active caspase-3 level, were quantified by ELISA and immunohistochemistry. Liver functions, oxidative stress parameters and myeloperoxidase activity were measured. MTT assay of hepG2 cells treated with recombinant Wnt3a (10ng/ml) in presence or absence of HP (100μM) was performed.

KEY FINDINGS

HCC group exhibited a significant increase in Wnt3a, β-catenin, Cyclin D1 and Wnt5a gene expressions, as well as, their protein levels. HP significantly prevented TAA-activated Wnt3a/β-catenin and Wnt5a pathways. Moreover, HP exerted hepatoprotective effect by significantly improving the oxidative imbalance, inflammation and liver function parameters, serum ALT, AST activities, and albumin level.

SIGNIFICANCE

Our study is the first to report the possible role of Wnt3a/β-catenin and Wnt5a pathways in TAA-induced early HCC model in rats. HP has a prophylactic effect against hepatocarcinogenesis via preventing the induction of both canonical and non-canonical Wnt pathways.

The co-chaperone UNC45A is essential for the expression of mitotic kinase NEK7 and tumorigenesis

Cumulative evidence suggests that the heat shock protein 90 (Hsp90) co-chaperone UNC-45 myosin chaperone A (UNC45A) contributes to tumorigenesis and that its expression in cancer cells correlates with proliferation and metastasis of solid tumors. However, the molecular mechanism by which UNC45A regulates cancer cell proliferation remains largely unknown. Here, using siRNA-mediated gene silencing and various human cells, we report that UNC45A is essential for breast cancer cell growth, but is dispensable for normal cell proliferation. Immunofluorescence microscopy, along with gene microarray and RT-quantitative PCR analyses, revealed that UNC45A localizes to the cancer cell nucleus, where it up-regulates the transcriptional activity of the glucocorticoid receptor and thereby promotes expression of the mitotic kinase NIMA-related kinase 7 (NEK7). We observed that UNC45A-deficient cancer cells exhibit extensive pericentrosomal material disorganization, as well as defects in centrosomal separation and mitotic chromosome alignment. Consequently, these cells stalled in metaphase and cytokinesis and ultimately underwent mitotic catastrophe, phenotypes that were rescued by heterologous NEK7 expression. Our results identify a key role for the co-chaperone UNC45A in cell proliferation and provide insight into the regulatory mechanism. We propose that UNC45A represents a promising new therapeutic target to inhibit cancer cell growth in solid tumor types.

Hepatoprotective Effect of Curcumin on Hepatocellular Carcinoma Through Autophagic and Apoptic Pathways

BACKGROUND AND RATIONALE

Microtubule-associated protein light chain 3-II (LC3-II), and Sequestosome-1 (SQSTM1) are proteins that can be used as markers for autophagic pathway. Bcl-2 protein is reported to be inversely correlated with apoptosis. We aimed to investigate the effects of curcumin on liver inflammation and fibrosis up to the first dysplastic stage of Hepatocellular carcinoma (HCC) induced by Thioacetamide (TAA) in rats and to clarify the effects of curcumin on LC3-II, SQSTM1, and Bcl-2. Male Sprague-Dawley rats were randomized into four groups: Control group, TAA group, Curcumin low-dose group, and Curcumin highdose group. The last three groups received TAA 200 mg/kg i.p. twice weekly for 18 weeks. Oxidative stress markers as hepatic malondialdehyde (MDA) concentration and superoxide dismutase (SOD) activity were measured by colorimetric methods. Hepatic SQSTM1 concentration was measured by ELISA, and gene expression levels of Bcl-2, and LC3-II were measured by RT-PCR.We also investigated the in vitro effect of curcumin on HepG2 cells viability through MTT assay, and the involvement of autophagy in this effect.

RESULTS

Curcumin increased the survival percent in rats, decreased -fetoprotein (AFP) concentration, and serum aspartate aminotransferase (AST) activity, and increased serum albumin concentration. Curcumin also significantly reduced oxidative stress in liver, inhibited apoptosis, and induced autophagy. In vitro, curcumin (50 µM) decreased HepG2 cells viabilityand the concentration of SQSTM1.

CONCLUSIONS

Curcumin leads to protection against TAA induced HCC up to the first dysplastic stage through activating autophagic pathway and inhibiting apoptosis. Also, the antioxidant activity of curcumin almost prevents liver fibrosis.

Potential roles of adenosine deaminase-2 in diabetic retinopathy

The early activation of microglia that induces retinal inflammation in DR may serve as a target for therapeutic intervention of DR. Our demonstration that retinal inflammation is attenuated via adenosine receptor A(2A)AR supports the hypothesis that a mechanism to maintain extracellular concentrations of adenosine important in normal physiology is impaired in DR. Extracellular concentrations of adenosine are regulated by the interplay of equiliberative nucleoside transporter (ENT)s with enzymes of adenosine metabolism including adenosine deaminase-1 (ADA1), adenosine kinase (AK) and CD73. In the vertebrates but not rodents, a macrophage-associated ADA2 is identified. The role of ADA2 is, therefore, understudied as the sequencing probes or antibodies to mouse ADA2 are not available. We identified increased ADA2 expression and activity in human and porcine retinas with diabetes, and in Amadori glycated albumin (AGA)- or hyperglycemia-treated porcine and human microglia. In rodent as well as porcine cells, modulation of TNF-α release is mediated by A(2A)AR. Quantitative analysis of normal and diabetic porcine retinas reveals that while the expression levels of ADA2, A2AAR, ENT1, TNF-α and MMP9 are increased, the levels of AK are reduced during inflammation as an endogenous protective mechanism. To determine the role of ADA2, we found that AGA induces ADA2 expression, ADA2 activity and TNF-α release, and that TNF-α release is blocked by ADA2-neutralizing antibody or ADA2 siRNA, but not by scrambled siRNA. These results suggest that retinal inflammation in DR is mediated by ADA2, and that the anti-inflammatory activity of A(2A)AR signaling is impaired in diabetes due to increased ADA2 activity.

Protective effect of vanillin on diabetic nephropathy by decreasing advanced glycation end products in rats

AIMS

Diabetic nephropathy (DN) is a common chronic microvascular complication of both types of diabetes mellitus, which leads to renal dysfunction and subsequent need of dialysis and organ transplantation. Advanced glycation end products (AGEs) are metabolic consequence of hyperglycemia and are main contributory factor in the DN pathogenesis through mediating establishment of oxidative status and chronic inflammatory milieu. This study aimed to explore the impact of vanillin on preventing the progression of DN.

MAIN METHODS

Experimental DN model was established in rats utilizing streptozotocin. Serum concentration of AGEs and Interleukin-6 (IL-6) and transforming growth factor β1 (TGFβ1) levels in kidney homogenate were assessed using ELISA technique. Also, we evaluated the expression of nuclear factor kappa B (NF-κB) using immunohistochemistry.

KEY FINDINGS

Treatment with vanillin for 8 weeks significantly ameliorated DN. Vanillin significantly decreased hyperglycemia and improved kidney function reflected by decreased serum levels of blood urea nitrogen, creatinine, and decreased proteinuria. Also, vanillin significantly decreased malondialdehyde content and elevated superoxide dismutase activity in renal tissues. Moreover, vanillin decreased renal expression of NF-κB and renal concentrations of IL-6, TGFβ1 and collagen. In addition, vanillin significantly decreased serum AGEs concentration. Also, vanillin attenuated histological abnormalities in kidney architecture.

SIGNIFICANCE

Vanillin, which is a cheap and abundant natural product, exhibited anti-AGEs, antioxidant, anti-inflammatory and anti-fibrotic activities. These activities might be helpful and potent mechanisms in preventing the progression of DN.

Inhibition of the signaling pathway of syndecan-1 by synstatin: A promising anti-integrin inhibitor of angiogenesis and proliferation in HCC in rats

AIM OF WORK

The study was conducted for evaluation of the antitumor activity of SSTN92-119 against HCC induced by thioacetamide in rats.

METHODS

Sixty male Sprague-Dawley rats were randomized into four equal groups: Control, SSTN92-119, HCC, and HCC + SSTN92-119. Liver function tests were measured in serum. Liver homogenate was used for determination of: i) integrinαѴβ3 (ITGαѴβ3), insulin like growth factor-1 receptor (IGF-1R), vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2) and alpha-fetoprotein (AFP) levels by ELISA, ii) syndecan-1 (CD-138), IGF-1R and VEGF genes expressions by qRT-PCR, iii) MDA, NO, GSH concentrations and SOD activity. Histopathological and immunohistochemical examination of liver tissue was performed.

RESULTS

SSTN92-119 decreased HCC-induced elevation in ALT, AST, ALP and GGT activities and reversed HCC-induced reduction in total protein and albumin concentrations significantly. SSTN92-119 significantly elevated hepatic SOD and GSH and reduced both NO and MDA levels. Protein levels of ITGαѴβ3, IGF-1R, VEGF, FGF-2 and AFP were decreased in HCC- SSTN92-119 group as well as gene expression of CD-138, IGF-1R and VEGF compared with HCC group.

CONCLUSIONS

SSTN92-119 down regulates ITGαѴβ3 receptor and subsequently reduces the activation of angiogenic growth factors VEGF and FGF-2. Therefore, SSTN92-119 is becoming a promising anti-integrin αѴβ3 that inhibits angiogenesis and proliferation in HCC.

Phenethyl isothiocyanate potentiates anti-tumour effect of doxorubicin through Akt-dependent pathway

The present study aims to investigate the in vivo and in vitro anti-tumour properties of phenethyl isothiocyanate (PEITC) alone and in combination with doxorubicin (Dox). The anti-tumour activity was evaluated in vitro by MTT assay using cultured human breast cancer cell line (MCF-7) and human hepatoma cell line (HepG-2) cell lines. In vivo, Ehrlich solid tumour model was used. Tumour volume, weight and antioxidant parameters were determined. Immunohistochemistry analysis for active (cleaved) caspase-3 was also performed. We tested the effect of PEITC treatment on pAkt/Akt ratio, NF-κB p65 DNA binding activity and caspase-9 enzyme activity in both MCF-7 and HepG-2 cell lines. Effect of PEITC treatment on cell migration was assessed by wound healing assay. PEITC and/or Dox treatment significantly inhibited solid tumour volume and tumour weight when compared with control mice. PEITC treatment significantly reduced oxidative stress caused by Dox treatment as indicated by significant increase in total antioxidant capacity and decrease in malondialdehyde level. Microscopic examination of tumour tissues showed a significant increase in active (cleaved) caspase-3 expression in PEITC and/or Dox treated groups. PEITC showed a dose-dependent inhibition of MCF-7 and HepG-2 cellular viability. PEITC inhibited Akt and NF-κB activation and increased caspase-9 activity in a dose-dependent manner. PEITC treatment effectively inhibited both MCF-7 and HepG-2 cell migration. We can conclude that PEITC acts via multiple molecular targets to elicit anti-carcinogenic activity. PEITC/Dox combination therapy might be a potential novel strategy, which may benefit patients with breast and liver cancers.

Reno-protective effect of NECA in diabetic nephropathy: implication of IL-18 and ICAM-1

Diabetic nephropathy (DN) remains the most common cause of end-stage renal disease. Although, adenosine acts as a local modulator with a cytoprotective function, extracellular adenosine usually disappears quickly due to a rapid uptake into adjacent cells. Therefore, we investigated the effect of 5'-(N-ethylcarboxamido)-adenosine (NECA), a stable, nonselective adenosine receptor agonist, on diabetes-induced increases in inflammatory cytokines and adhesion molecules. The enhancement of adenosine receptor action by NECA was examined in the renal tissues of rats with streptozotocin-induced diabetes. Daily i.p. injections of NECA at 0.3 mg/kg/day were given to rats, over a two-week period, six weeks after the induction of diabetes. Morphological changes were assessed in kidney sections. Oxidative stress was examined by measuring tissue malondialdehyde. Gene expression of interleukin (IL)-18, tumor necrosis factor (TNF)-α and intercellular adhesion molecule (ICAM)-1 was measured by real-time PCR. Activation of cellular, proapoptotic pathways was demonstrated by measuring the activation of c-Jun NH(2)-terminal kinases (JNK)-mitogen-activated-protein kinase (MAPK). We found that diabetes-induced malondialdehyde formation activated the production of IL-18, TNF-α and ICAM-1, which, in turn, activated pro-apoptotic pathways in diabetic rats. Treatment with NECA protected diabetic rats by exerting hypoglycemic and antioxidant effects as well as reducing gene expression of proinflammatory cytokines. These effects were associated with deactivation of JNK-MAPK. In addition, diabetic rats treated with NECA showed mild glomerular effects and vacuolation of tubular epithelium. We can conclude that activation of adenosine receptors is a potential therapeutic target in DN. NECA acts via multiple mechanisms including: reducing diabetes-induced oxidative stress, inhibiting gene expression of IL-18, TNF-α and ICAM-1, and blocking activation of the JNK-MAPK pathway.

Chemosensitizing effect of Alpinia officinarum rhizome extract in cisplatin-treated rats with hepatocellular carcinoma

This study was conducted to estimate the preventing and sensitizing efficiency of Alpinia officinarum rhizome extract (AORE) in an experimental model of hepatocellular carcinoma (HCC) +/- cisplatin. HCC was induced by a single intraperitoneal (i.p) dose of diethylnitrosamine (DENA, 200mg/kg). After 14 days, phenobarbitone (PB, 0.05%) was added to drinking water for 14 weeks to promote hepatocarcinogenesis. Cisplatin (CP) was given in a dose of 1.5 mg/kg (i.p), twice a week, alone or with AORE (400 mg/kg daily, orally) for 21 days. AORE was tried as a protective before the induction of HCC for three weeks as well. Results revealed that DENA/PB elevated hepatic indices as ALT and AST and total bilirubin with declining serum total protein. It increased oxidative stress, as hepatic malondialdehyde (MDA) with depressed hepatic reduced glutathione (GSH) contents, superoxide dismutase (SOD) and catalase activities. This was accompanied by an increase in hepatic expression of antioxidant genes (thioredoxin and glutaredoxin). Hepatocarcinogenesis was detected by histopathological changes in liver sections and the elevation of serum alpha-fetoprotein (AFP) level. Treatment with CP partially restored altered hepatic functions and oxidative stress markers. It also showed a partial decrease in the expression of antioxidant genes, improving histopathological changes in the liver and AFP level in serum. The treatment with AORE alone or AORE+CP enhanced hepatic function and oxidative stress markers. It also caused a decrease in the expression of antioxidant genes and improved histopathological changes in liver and serum AFP level. This effect is more potent than the treatment with CP alone. Our study suggested that AORE can be used as a promising natural chemoprevention or a chemosensitizing agent against hepatocarcinogenesis.

Adenosine Deaminase-2-Induced Hyperpermeability in Human Retinal Vascular Endothelial Cells Is Suppressed by MicroRNA-146b-3p

PURPOSE

We recently demonstrated that adenosine deaminase-2 (ADA2) contributes to diabetic retinopathy (DR) via up-regulating the production of inflammatory cytokines in macrophages. Also, microRNA (miR)-146b-3p has the ability to inhibit ADA2. The goal of this study was to investigate the potential role of ADA2 and therapeutic benefit of miR-146b-3p in retinal inflammation and endothelial barrier dysfunction during diabetes.

METHODS

Adenosine deaminase-2 activity was determined by colorimetric method in diabetic human vitreous. Human monocyte cell line U937 was differentiated into macrophages and then treated with amadori glycated albumin (AGA), and conditioned medium (CM) was used to assess the changes in ADA2 activity and TNF-α and IL-6 levels by ELISA. Also, macrophages were transfected with miR-146b-3p before treatment with AGA. Permeability of human retinal endothelial cells (hRECs) was assessed by electric cell-substrate impedance sensing (ECIS) after treatment with macrophage CM. Zonula occludens (ZO)-1 was examined by immuno-fluorescence in hRECs. Leukocyte adhesion was assessed in hRECs by measuring myeloperoxidase (MPO) activity and intercellular adhesion molecule-1 (ICAM-1) expression.

RESULTS

Adenosine deaminase-2 activity was significantly increased in diabetic human vitreous. ADA2 activity and TNF-α and IL-6 levels were significantly increased in human macrophages by AGA treatment. Amadori glycated albumin-treated macrophage CM significantly increased hREC permeability, disrupted ZO-1 pattern, and increased leukocyte adhesion to hRECs through up-regulating ICAM-1. All these changes were reversed by miR-146b-3p.

CONCLUSIONS

Adenosine deaminase-2 is implicated in breakdown of the blood-retinal barrier (BRB) in DR through macrophages-derived cytokines. Therefore, inhibition of ADA2 by miR-146b-3p might be a useful tool to preserve BRB function in DR.

Evaluation of antiglypican-3 therapy as a promising target for amelioration of hepatic tissue damage in hepatocellular carcinoma

In Egypt, hepatocellular carcinoma (HCC) was predicted to continue to rise over the next few decades causing a national problem. Meanwhile, glypican-3 (GPC3), a highly expressed glypican, has emerged as a potential target for HCC immunotherapy. Therefore, we aimed to identify the impact of blocking GPC3 on liver damage in HCC as well as a possible mechanism. Fifty four HCC patients, 20 cirrhotic patients and 10 healthy subjects were recruited. Serum levels of GPC3, sulfatase-2 (SULF-2), heparan sulfate proteoglycan (HSPG), insulin-like growth factor-II (IGF-II) were measured by ELISA. In parallel, HCC was induced in 40 male Sprague-Dawley rats in presence/absence of antiGPC-3. Liver impairment was detected by investigating liver sections stained with hematoxylin/eosin and serum α-fetoprotein (AFP). Liver homogenates of GPC3, SULF-2, and HSPG were measured by ELISA. Gene expression of caspase-3 and IGF-II were assayed by RT-PCR. HCC patients showed significant elevated serum levels of GPC3, IGF-II and SULF-2 accompanied by decreased HSPG. However, treatment of HCC rats with antiGPC-3 significantly reduced serum AFP and showed nearly normal hepatocytes. In addition, antiGPC-3 significantly reduced elevated liver homogenates protein levels of GPC3 and SULF-2 and gene expression of IGF-II and caspase-3. antiGPC-3 restored the reduced hepatic HSPG. antiGPC-3 showed anti-tumor activity as well as hepatoprotective effects. antiGPC-3-chemoprotective effect can be explained by forced reduction of IGF-II expression, restoration of HSPGs, deactivation of SULF-2 and reduction of gene expression of caspase-3. Targeting GPC3 is a promising therapeutic approach for HCC.

Role of alpha-lipoic acid in the management of anemia in patients with chronic renal failure undergoing hemodialysis

INTRODUCTION

Anemia associated with chronic kidney disease is a serious complication necessitating expenditure of huge medical efforts and resources. This study investigates the role of alpha-lipoic acid (ALA) in end stage renal disease patients undergoing hemodialysis. By the virtue of its antioxidative effects, ALA is expected to act as an erythropoietin (EPO) adjuvant, and also has extended beneficial effects on endothelial dysfunction.

METHODS

Forty-four patients undergoing hemodialysis and receiving EPO were randomized into two groups: the first group received ALA 600 mg once daily for 3 months; while the other group represented the control group. Parameters measured at baseline and at end of study were hemoglobin, EPO doses, EPO resistance index (ERI), iron store indices, malondialdehyde, oxidized low-density lipoprotein (ox-LDL), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and asymmetric dimethylarginine (ADMA), as well as routine laboratory follow-up.

RESULTS

EPO doses and ERI were significantly decreased in the treatment group, while they did not change in the control group. Hemoglobin, iron store indices, malondialdehyde, oxidized ox-LDL, IL-6, TNF-α, and ADMA were similar in both treatment and control groups at baseline, and did not change by the end of study period. Likewise, routine laboratory measures were not affected by the treatment.

CONCLUSION

ALA could be used in hemodialysis patients to reduce requirements for EPO. However, larger and longer term studies are required to clarify the exact role of ALA in hemodialysis as well as in pre-hemodialysis patients.

Calcium channel α2δ1 subunit as a novel biomarker for diagnosis of hepatocellular carcinoma

OBJECTIVE

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. The identification of new simple, inexpensive and highly accurate markers for HCC diagnosis and screening is needed. This case-control study evaluates the role of annexin A2 and voltage-gated calcium channels α2δ1 subunit as serum biomarkers for HCC diagnosis.

METHODS

The study comprised three groups: group 1, 50 patients with an initial diagnosis of HCC associated with chronic hepatitis C virus infection; group 2, 25 patients diagnosed with chronic hepatitis C virus infection and cirrhosis without any evidence of HCC; and group 3, 15 healthy controls. All participants were subjected to clinical and laboratory investigations, and radiological scanning. The serum levels of alpha-fetoprotein (AFP), annexin A2, and the α2δ1 subunit were evaluated by using ELISA technique.

RESULTS

The serum levels of annexin A2 significantly increased in patients with HCC (10.4±2.5 ng/mL; P<0.001) or with cirrhosis (9.31±1.8 ng/mL;P<0.001) comparing to that of healthy controls (0.296±0.09 ng/mL). However, there was no significant difference in serum annexin A2 levels in patients with HCC comparing to those with cirrhosis. Serum α2δ1 subunit significantly increased in patients with HCC (20.12±3.7 ng/mL) comparing to that in patients with cirrhosis (10.41±3.4 ng/mL,P<0.001) and healthy controls (10.2±2.9 ng/mL,P<0.001).

CONCLUSIONS

The serum α2δ1 subunit may function as a new biomarker for HCC diagnosis. Conversely, serum annexin A2 has low diagnostic value as an HCC marker, especially in patients with underlying cirrhosis.

Serum Cystatin C as a Biomarker in Diffuse Large B-Cell Lymphoma

Elevated serum levels of cystatin C are found to be related to poor outcome and metastatic potential of some malignant disorders. To evaluate the clinical prominence of serum cystatin C in diffuse large B-cell lymphoma (DLBCL), blood samples were obtained from 58 patients at the time of diagnosis and paired blood samples were obtained from 22 patients at the time of remission. Also, serum cystatin C level was measured in matched healthy controls. Serum cystatin C levels were significantly more elevated in DLBCL patients than in controls (p < 0.0001). Furthermore, paired-sample analysis revealed that pretreatment cystatin C levels were reduced significantly in patients who achieved remission after therapy (p = 0.016). High serum cystatin C levels were correlated with age over 60 years (p = 0.049), extra-nodal involvement (p = 0.005) and with high serum lactate dehydrogenase (LDH) (p < 0.013). Elevated serum cystatin C levels were associated with extra-nodal involvement and they were significantly reduced to normal range after the remission. However, Kaplan-Meier curves revealed no survival difference in the pretreatment serum cystatin C levels. Therefore, serum cystatin C may be a novel biomarker that reflects tumor burden in DLBCL but bears no prognostic significance regarding survival.

Diagnostic and Prognostic Value of Talin-1 and Midkine as Tumor Markers in Hepatocellular Carcinoma in Egyptian Patients

Background: Hepatocellular carcinoma (HCC) is a main cause of cancer death all over the world. Treatment and outcome of HCC based on its early diagnosis. This study was conducted to estimate the role of talin-1 and midkine in combination with total antioxidant capacity (TAC) as tumor markers in HCC patients. Methods: Serum levels of talin-1 and midkine were measured in 90 Egyptian subjects including 44 patients with HCC, 31patients with cirrhosis and 15 healthy controls using enzyme-linked immunosorbent assay (ELISA) technique. While a colorimetric method was used for measurement of TAC. Results: Serum talin-1 in HCC patients was significantly lower than that in patients with cirrhosis (P<0.001) and normal control (P<0.001). In addition, increased invasion and metastasis correlated with reduced talin-1 level. Serum midkine in HCC patients was significantly higher compared to cirrhotic patients (P<0.001) and normal control (P<0.001). Midkine at a cut off value of 1683 pg/ml showed a sensitivity of (81.82%) and specificity of (83.87%). While alpha-fetoprotein (AFP) at a cut off value of 200 ng/ml had a sensitivity of (52.27%), while specificity was (96.77%). Midkine was positive in 80.9% of HCC patients with negative AFP. Serum TAC was significantly decreased in HCC patients when compared with control group (P<0.001). Conclusion: Talin-1 may be implicated in the carcinogenesis and metastasis of HCC and can be used as a useful tumor marker for HCC. Midkine may be a potential diagnostic marker for HCC and may be used in addition to AFP to increase the sensitivity of HCC detection.

Sesamol protects against liver fibrosis induced in rats by modulating lysophosphatidic acid receptor expression and TGF-β/Smad3 signaling pathway

The present study aimed to investigate the hepatoprotective effect of sesamol (SML), a nutritional phenolic compound obtained from sesame seeds, in liver fibrosis induced by thioacetamide (TAA) in rats and to explore the underlying mechanisms. Thirty-two male Sprague-Dawley rats were equally divided into four groups: control, TAA, TAA + SML 50 mg/kg, and TAA + SML 100 mg/kg groups. Liver functions and hepatic contents of glutathione (GSH) and malondialdehyde (MDA) were measured colorimetrically. Gene expressions of lysophosphatidic acid receptor (LPAR)-1 and -3, connective tissue growth factor (CTGF), transforming growth factor (TGF)-β1, small mothers against decapentaplegic (Smad)-3 and -7, α-smooth muscle actin (α-SMA), and cytokeratin 19 (CK19) were analyzed by qRT-PCR. Moreover, phosphorylated Smad3 (pSmad3) was quantified by ELISA. Additionally, TGF-β1, α-SMA, CK19, and vascular endothelial growth factor (VEGF) protein concentrations were semi-quantitatively analyzed by immunostaining of liver sections. SML treatment markedly improved liver index and liver functions. Moreover, SML protected against liver fibrosis in a dose-dependent manner as indicated by down-regulation of LPAR1, LPAR3, CTGF, TGF-β1/Smad3, and α-SMA expressions and a decrease in pSmad3 level, as well as an up-regulation of Smad7 expression. In addition, SML suppressed ductular reaction hinted by the decrease in CK19 expression. These results reveal the anti-fibrotic effect of SML against liver fibrosis that might be attributed to down-regulation of LPAR1/3 expressions, inhibition of TGF-β1/Smad3 pathway, and ductular reaction.