Reno-protective effect of protocatechuic acid is independent of sex-related differences in murine model of UUO-induced kidney injury.

BACKGROUND: Obstructive nephropathy is a condition often caused by urinary tract obstruction either anatomical (e.g., tumors), mechanical (e.g., urolithiasis), or compression (e.g., pregnancy) and can progress to chronic kidney disease (CKD). Studies have shown sexual dimorphism in CKD, where males were found to have a more rapid decline in kidney function following kidney injury compared to age-matched females. Protocatechuic acid (PCA), an anti-oxidant and anti-inflammatory polyphenolic compound, has demonstrated promising effects in mitigating drug-induced kidney injuries. The current study aims to explore sexual dimorphism in kidney injury after unilateral ureteral obstruction (UUO) and assess whether PCA treatment can mitigate kidney injury in both sexes. METHODS: UUO was induced in 10-12 weeks old male and female C57BL/6J mice. Mice were categorized into four groups (n = 6-8/group); Sham, Sham plus PCA (100 mg/kg, I.P daily), UUO, and UUO plus PCA. RESULTS: After 2 weeks of induction of UUO, markers of kidney oxidative stress (TBARs), inflammation (IL-1α and IL-6), tubular injury (neutrophil gelatinase-associated lipocalin, NGAL and urinary kidney injury molecule-1, KIM-1), fibrosis (Masson's trichrome staining, collagen IV expression, MMP-2 and MMP-9) and apoptosis (TUNEL+ cells, active caspase-1 and caspase-3) were significantly elevated in both males and females relative to their sham counterparts. Males exhibited significantly greater kidney oxidative stress, inflammation, fibrosis, and apoptosis after induction of UUO when compared to females. PCA treatment significantly attenuated UUO-induced kidney injury, inflammation, fibrosis, and apoptosis in both sexes. CONCLUSION: Our findings suggest a differential gender response to UUO-induced kidney injury with males being more sensitive to UUO-induced kidney inflammation, fibrosis, and apoptosis than age-matched females. Importantly, PCA treatment reduced UUO-induced kidney injury in a sex-independent manner which might be attributed to its anti-oxidant, anti-inflammatory, anti-fibrotic, and anti-apoptotic properties.

Endogenous estradiol contributes to vascular endothelial dysfunction in premenopausal women with type 1 diabetes.

BACKGROUND: Endogenous estrogen is cardio-protective in healthy premenopausal women. Despite this favorable action of estrogen, animal models depict a detrimental effect of estradiol on vascular function in the presence of diabetes. The present study sought to determine the role of endogenous estradiol on endothelial function in women with type 1 diabetes. METHOD: 32 women with type 1 diabetes (HbA1c = 8.6 ± 1.7%) and 25 apparently healthy women (HbA1c = 5.2 ± 0.3%) participated. Flow-mediated dilation (FMD), a bioassay of nitric-oxide bioavailability and endothelial function was performed during menses (M) and the late follicular (LF) phase of the menstrual cycle to represent low and high concentrations of estrogen, respectively. In addition, a venous blood sample was collected at each visit to determine circulating concentrations of estradiol, thiobarbituric acid reactive substances (TBARS), and nitrate/nitrite (NOx), biomarkers of oxidative stress and nitric oxide, respectively. Data were collected in (1) 9 additional women with type 1 diabetes using oral hormonal birth control (HBC) (HbA1c = 8.3 ± 2.1%) during the placebo pill week and second active pill week, and (2) a subgroup of 9 demographically matched women with type 1 diabetes not using HBC (HbA1c = 8.9 ± 2.1%). RESULTS: Overall, estradiol was significantly increased during the LF phase compared to M in both type 1 diabetes (Δestradiol = 75 ± 86 pg/mL) and controls (Δestradiol = 71 ± 76 pg/mL); however, an increase in TBARS was only observed in patients with type 1 diabetes (ΔTBARS = 3 ± 13 µM) compared to controls (ΔTBARS = 0 ± 4 µM). FMD was similar (p = 0.406) between groups at M. In addition, FMD increased significantly from M to the LF phase in controls (p = 0.024), whereas a decrease was observed in type 1 diabetes. FMD was greater (p = 0.015) in patients using HBC compared to those not on HBC, independent of menstrual cycle phase. CONCLUSION: Endogenous estradiol increases oxidative stress and contributes to endothelial dysfunction in women with diabetes. Additionally, HBC use appears to be beneficial to endothelial function in type 1 diabetes.

Acute nitric oxide synthase inhibition induces greater increases in blood pressure in female versus male Wistar Kyoto rats.

Nitric oxide (NO) contributes to blood pressure (BP) regulation via its vasodilatory and anti-inflammatory properties. We and others previously reported sex differences in BP in normotensive and hypertensive rat models where females have lower BP than age-matched males. As females are known to have greater NO bioavailability than age-matched males, the current study was designed to test the hypothesis that anesthetized female normotensive Wistar Kyoto rats (WKY) are more responsive to acute NOS inhibition-induced increases in BP compared to male WKY. Twelve-week-old male and female WKY were randomized to infusion of the nonspecific NOS inhibitor NG -nitro-L-arginine methyl ester (L-NAME, 1 mg/kg/min) or selective NOS1 inhibition with vinyl-L-NIO (VNIO, 0.5 mg/kg/min) for 60 min. Mean arterial BP, glomerular filtration rate (GFR), urine volume, and electrolyte excretion were assessed before, and during L-NAME or VNIO infusion. L-NAME and VNIO significantly increased BP in both sexes; however, the increase in BP with L-NAME infusion was greater in females versus males compared to baseline BP values. Acute infusion of neither L-NAME nor VNIO for 60 min altered GFR in either sex. However, urine volume, sodium, chloride and potassium excretion levels increased comparably in male and female WKY with L-NAME and VNIO infusion. Our findings suggest sex differences in BP responses to acute non-isoform-specific NOS inhibition in WKY, with females being more responsive to L-NAME-induced elevations in BP relative to male WKY. However, sex differences in the BP response did not coincide with sex differences in renal hemodynamic responses to acute NOS inhibition.

Hyperhomocysteinemia dysregulates plasma levels of polyunsaturated fatty acids-derived eicosanoids.

Hyperhomocysteinemia (HHcy) contributes to the incidence of many cardiovascular diseases (CVD). Our group have previously established crucial roles of eicosanoids and homocysteine in the incidence of vascular injury in diabetic retinopathy and renal injury. Using cystathionine-ß-synthase heterozygous mice (cßs+/-) as a model of HHcy, the current study was designed to determine the impact of homocysteine on circulating levels of lipid mediators derived from polyunsaturated fatty acids (PUFA). Plasma samples were isolated from wild-type (WT) and cßs+/- mice for the assessment of eicosanoids levels using LC/MS. Plasma 12/15-lipoxygenase (12/15-LOX) activity significantly decreased in cßs+/- vs. WT control mice. LOX-derived metabolites from both omega-3 and omega-6 PUFA were also reduced in cßs+/- mice compared to WT control (P < 0.05). Contrary to LOX metabolites, cytochrome P450 (CYP) metabolites from omega-3 and omega-6 PUFA were significantly elevated in cßs+/- mice compared to WT control. Epoxyeicosatrienoic acids (EETs) are epoxides derived from arachidonic acid (AA) metabolism by CYP with anti-inflammatory properties and are known to limit vascular injury, however their physiological role is limited by their rapid degradation by soluble epoxide hydrolase (sEH) to their corresponding diols (DiHETrEs). In cßs+/- mice, a significant decrease in the plasma EETs bioavailability was obvious as evident by the decrease in EETs/ DiHETrEs ratio relative to WT control mice. Cyclooxygenase (COX) metabolites were also significantly decreased in cßs+/- vs. WT control mice. These data suggest that HHcy impacts eicosanoids metabolism through decreasing LOX and COX metabolic activities while increasing CYP metabolic activity. The increase in AA metabolism by CYP was also associated with increase in sEH activity and decrease in EETs bioavailability. Dysregulation of eicosanoids metabolism could be a contributing factor to the incidence and progression of HHcy-induced CVD.

Sexual dimorphism in renal heme oxygenase-1 and arachidonic acid metabolizing enzymes in spontaneously hypertensive rats versus normotensive Wistar Kyoto rats.

Numerous studies have demonstrated a sexual dimorphism in blood pressure (BP) control in spontaneously hypertensive rats (SHR), however the mechanisms remain to be further elucidated. Based on the established role of arachidonic acid metabolites and heme oxygenase (HO) in BP control, we hypothesize that higher BP in male SHR is associated with differential expression in renal HO and arachidonic acid metabolizing enzymes vs. female SHR. Higher BP in male SHR coincided with significant increases in renal cortical superoxide production and thiobarbituric acid reactive substances (TBARs) levels as measures of oxidative stress compared to normotensive female WKY and female SHR. The elevations in BP and oxidative stress in male SHR were also associated with a decrease in cortical heme oxygenase-1 (HO-1) expression when compared to normotensive female WKY. Although there was no sex or strain differences in cortical expression of the epoxyeicosatrienoic acids (EETs) producing enzyme, cytochrome P450 epoxygenase (CYP2C23), in male and female SHR and WKY, SHR had greater expression of the EETs metabolizing enzyme, soluble epoxide hydrolase (sEH) vs. WKY. Cortical expression of the 20-hydroxyeicosatetraenoic acid (20-HETE) producing enzyme, cytochrome P450 hydroxylase (CYP4A), was less in female WKY and SHR compared to strain-matched males and cortical 20-HETE levels were also less in female SHR vs. male SHR. Cortical cyclooxygenase-2 (COX-2) expression was significantly greater in female SHR and WKY vs. males and cortical prostaglandin E2 (PGE2) levels in female SHR was significantly greater than male WKY. In conclusion, our data suggest that sex differences in renal oxidative stress, HO-1 and arachidonic acid metabolizing enzymes could contribute to sexual dimorphism in hypertension in young SHR.

Sex differences in hypertension: lessons from spontaneously hypertensive rats (SHR).

Although numerous clinical and experimental studies have clearly identified a sexual dimorphism in blood pressure control, the mechanism(s) underlying gender differences in blood pressure remain unclear. Over the past two decades, numerous laboratories have utilized the spontaneously hypertensive rats (SHR) as an experimental model of essential hypertension to increase our understanding of the mechanisms regulating blood pressure in males and females. Previous work by our group and others have implicated that differential regulation of adrenergic receptors, the renin-angiotensin system, oxidative stress, nitric oxide bioavailability and immune cells contribute to sex differences in blood pressure control in SHR. The purpose of this review is to summarize previous findings to date regarding the mechanisms of blood pressure control in male versus female SHR.

Effect of Everolimus versus Bone Marrow-Derived Stem Cells on Glomerular Injury in a Rat Model of Glomerulonephritis: A Preventive, Predictive and Personalized Implication.

Glomerular endothelial injury and effectiveness of glomerular endothelial repair play a crucial role in the progression of glomerulonephritis. Although the potent immune suppressive everolimus is increasingly used in renal transplant patients, adverse effects of its chronic use have been reported clinically in human glomerulonephritis and experimental renal disease. Recent studies suggest that progenitor stem cells could enhance glomerular endothelial repair with minimal adverse effects. Increasing evidence supports the notion that stem cell therapy and regenerative medicine can be effectively used in pathological conditions within the predictive, preventive and personalized medicine (PPPM) paradigm. In this study, using an experimental model of glomerulonephritis, we tested whether bone marrow-derived stem cells (BMDSCs) could provide better effect over everolimus in attenuating glomerular injury and improving the repair process in a rat model of glomerulonephritis. Anti-Thy1 glomerulonephritis was induced in male Sprague Dawley rats by injection of an antibody against Thy1, which is mainly expressed on glomerular mesangial cells. Additional groups of rats were treated with the immunosuppressant everolimus daily after the injection of anti-Thy1 or injected with single bolus dose of BMDSCs after one week of injection of anti-Thy1 (n = 6-8). Nine days after injection of anti-Thy1, glomerular albumin permeability and albuminuria were significantly increased when compared to control group (p < 0.05). Compared to BMDSCs, everolimus was significantly effective in attenuating glomerular injury, nephrinuria and podocalyxin excretion levels as well as in reducing inflammatory responses and apoptosis. Our findings suggest that bolus injection of BMDSCs fails to improve glomerular injury whereas everolimus slows the progression of glomerular injury in Anti-Thy-1 induced glomerulonephritis. Thus, everolimus could be used at the early stage of glomerulonephritis, suggesting potential implications of PPPM in the treatment of progressive renal injury.

Correction: Curcumin attenuates iron accumulation and oxidative stress in the liver and spleen of chronic iron-overloaded rats.

[This corrects the article DOI: 10.1371/journal.pone.0134156.].

Effect of Two Different Surface Treatments on Retention of Cosmopost with Two Different Core Materials.

OBJECTIVE: The objective of this study was to determine the effect of Cosmopost's two different surface treatments (sandblasting and silica coating) on persistence to various core materials using push-out test set-up. MATERIAL AND METHODS: A total of 30 Cosmoposts was used in this study. Cosmoposts were divided into three groups (10 samples each) according to the post-surface treatment received. Every category was additionally subdivided into two subgroups according to the type of core material (n = 5 samples). A specially designed copper mold was used for construction of different core materials with standardized dimensions around the posts, in such a way to ensure that the posts will be centralized. Surface roughness was estimated for all Cosmoposts, following different surface treatments using SEM. Cylindrical cores were fabricated of either composite resin or heat-pressed zirconia-containing glass-ceramic (IPS Empress Cosmo, Ivoclar Vivadent). Following the construction of different Core materials, samples were subjected to push-out test set-up to Evaluate the impact of various treatments on post/core bond strength. Data were collected, tabulated and statistically analyzed. SEM was performed on Cosmoposts following debonding of different post/core samples to determine their mode of failure. RESULTS: Results of push-out bond strength revealed that core material, surface treatment and the interaction between the two variables using Two-way ANOVA had a statistically significant effect on mean push-out bond strength. Regarding the effect of type of core material on Push-out bond strength, results showed that IPS Empress Cores showed statistically significant higher mean push-out bond strength to Cosmopost (36.4±9.7MPa) than composite cores (15.8±2.5 MPa). CONCLUSION: Within the limitations of this study, direct heat-pressed ceramic core was more beneficial for zirconia post buildups, than Composite Cores, since they provided higher bond strength. Thanks to a double improvement: increase in fracture resistance and retentive capacity to post. Also, Tribochemical Silicacoating technique was proved to be more effective in Cosmopost treatments than sandblasting technique.

Greater T Regulatory Cells in Females Attenuate DOCA-Salt-Induced Increases in Blood Pressure Versus Males.

Hypertension is the most common risk factor for cardiovascular disease, causing over 18 million deaths a year. Although the mechanisms controlling blood pressure (BP) in either sex remain largely unknown, T cells play a critical role in the development of hypertension. Further evidence supports a role for the immune system in contributing to sex differences in hypertension. The goal of the current study was to first, determine the impact of sex on the renal T-cell profiles in DOCA-salt hypertensive males and females and second, test the hypothesis that greater numbers of T regulatory cells (Tregs) in females protect against DOCA-salt-induced increases in BP and kidney injury. Male rats displayed greater increases in BP than females following 3 weeks of DOCA-salt treatment, although increases in renal injury were comparable between the sexes. DOCA-salt treatment resulted in an increase in proinflammatory T cells in both sexes; however, females had more anti-inflammatory Tregs than males. Additional male and female DOCA-salt rats were treated with anti-CD25 to decrease Tregs. Decreasing Tregs significantly increased BP only in females, thereby abolishing the sex difference in the BP response to DOCA-salt. This data supports the hypothesis that Tregs protect against the development of hypertension and are particularly important for the control of BP in females.

Salvianolic Acid B Slows the Progression of Breast Cancer Cell Growth via Enhancement of Apoptosis and Reduction of Oxidative Stress, Inflammation, and Angiogenesis.

Breast cancer is the current leading cause of cancer death in females worldwide. Although current chemotherapeutic drugs effectively reduce the progression of breast cancer, most of these drugs have many unwanted side effects. Salvianolic acid B (Sal-B) is a bioactive compound isolated from the root of Danshen Radix with potent antioxidant and anti-inflammatory properties. Since free radicals play a key role in the initiation and progression of tumor cells growth and enhance their metastatic potential, the current study was designed to investigate the antitumor activity of Sal-B and compare it with the antitumor activity of the traditional anticancer drug, cisplatin. In vitro, Sal-B decreased the human breast cancer adenocarcinoma (MCF-7) cells proliferation in a concentration and time dependent manner. In vivo and similar to cisplatin treatment, Sal-B significantly reduced tumor volume and increased the median survival when compared to tumor positive control mice group injected with Ehrlich solid carcinoma cell line (ESC). Sal-B decreased plasma level of malondialdehyde as a marker of oxidative stress and increased plasma level of reduced glutathione (GSH) as a marker of antioxidant defense when compared to control ESC injected mice. Either Sal-B or cisplatin treatment decreased tumor tissue levels of tumor necrosis factor (TNF-α), matrix metalloproteinase-8 (MMP-8), and Cyclin D1 in ESC treated mice. Contrary to cisplatin treatment, Sal-B did not decrease tumor tissue Ki-67 protein in ESC injected mice. Immunohistochemical analysis revealed that Sal-B or cisplatin treatment increased the expression of the apoptotic markers caspase-3 and P53. Although Sal-B or cisplatin significantly reduced the expression of the angiogenic factor vascular endothelial growth factor (VEGF) in ESC injected mice, only Sal-B reduced expression level of COX-2 in ESC injected mice. Our data suggest that Sal-B exhibits antitumor features against breast cancer cells possibly via enhancing apoptosis and reducing oxidative stress, inflammation, and angiogenesis.

A dual role of 12/15-lipoxygenase in LPS-induced acute renal inflammation and injury.

Recent studies suggest a potential role of bioactive lipids in acute kidney injury induced by lipopolysaccharide (LPS). The current study was designed to determine the profiling activities of various polyunsaturated fatty acid (PUFA) metabolizing enzymes, including lipoxygenases (LO), cyclooxygenase, and cytochrome P450 in the plasma of LPS-injected mice using LC-MS. Heat map analysis revealed that out of 126 bioactive lipids screened, only the 12/15-LO metabolite, 12-HETE, had a significant (2.24 ±â€¯0.4) fold increase relative to control (P = 0.0001) after Bonferroni Correction (BCF α = 0.003). We then determined the role of the 12/15-LO in LPS-induced acute kidney injury using genetic and pharmacological approaches. Treatment of LPS injected mice with the 12/15-LO inhibitor, baicalein, significantly reduced levels of renal injury and inflammation markers including urinary thiobarbituric acid reactive substance (TBARs), urinary monocyte chemoattractant protein-1 (MCP-1), renal interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Similarly, knocking-out of 12/15-LO reduced levels of renal inflammation and injury markers elicited by LPS injection. Next, we tested whether exogenous supplementation with docosahexaenoic acid (DHA) as a substrate would divert the role of 12/15-LO from being pro-inflammatory to anti-inflammatory via increased production of the anti-inflammatory metabolite. DHA treatment restored the decreased in plasma level of resolvin D2 (RvD2) and reduced renal injury in LPS-injected mice whereas DHA treatment failed to provide any synergistic effects in reducing renal injury in LPS injected 12/15-LO knock-out mice. The ability of RvD2 to protect kidney against LPS-induced renal injury was further confirmed by exogenous RvD2 which significantly reduced the elevation in renal injury in LPS injected mice. These data suggest a double-edged sword role of 12/15-LO in LPS-induced acute renal inflammation and injury, depending on the type of substrate available for its activity.

Increased arterial pressure in mice with overexpression of the ADHD candidate gene calcyon in forebrain.

The link between blood pressure (BP) and cerebral function is well established. However, it is not clear whether a common mechanism could underlie the relationship between elevated BP and cognitive deficits. The expression of calcyon, a gene abundant in catecholaminergic and hypothalamic nuclei along with other forebrain regions, is increased in the brain of the spontaneously hypertensive rat (SHR) which is a widely accepted animal model of essential hypertension and attention deficit hyperactivity disorder (ADHD). Previous studies demonstrated that mice with up-regulation of calcyon in forebrain (CalOE) exhibit deficits in working memory. To date, there is no evidence directly connecting calcyon to BP regulation. Here, we investigated whether forebrain up-regulation of calcyon alters BP using radiotelemetry. We found that CalOE mice exhibited higher mean arterial pressure (MAP) compared to tTA controls. Plasma norepinephrine levels were significantly higher in CalOE mice compared to tTA controls. Silencing the transgene with doxycycline normalized BP in CalOE mice, whereas challenging the mice with 4% high salt diet for 12 days exacerbated the MAP differences between CalOE and tTA mice. High salt diet challenge also increased proteinuria and urinary thiobarbituric acid reactive substances (TBARs) in tTA and CalOE; and the increases were more prominent in CalOE mice. Taken together, our data suggest that upregulation of calcyon in forebrain could increase BP via alterations in noradrenergic transmission and increased oxidative stress during high salt challenge. Overall, this study reveals that calcyon could be a novel neural regulator of BP raising the possibility that it could play a role in the development of vascular abnormalities.

Influence of the selective COX-2 inhibitor celecoxib on sex differences in blood pressure and albuminuria in spontaneously hypertensive rats.

We previously reported that female spontaneously hypertensive rats (SHR) have greater cyclooxygenase-2 (COX-2) expression in the renal medulla and enhanced urinary excretion of prostaglandin (PG) E2 (PGE2) metabolites compared to male SHR. Based on the role of COX-2-derived prostanoids in the regulation of cardiovascular health, the aim of the current study was to test the hypothesis that blood pressure (BP) in female SHR is more sensitive to COX-2 inhibition than in males. Seven week old male and female SHR were implanted with telemetry transmitters for continuous BP recording. After one week of baseline BP recording, male and female SHR were randomized to receive the selective COX-2 inhibitor celecoxib (10 mg/kg/day) or vehicle for six weeks (from 9 to 14 weeks of age). Female SHR had lower BP and albuminuria compared to male SHR as well as enhanced urinary excretion of PGE metabolite (PGEM), 6-keto PGF1α and thromboxane B2, indicators of PGE2, PGI2 and TXA2, respectively. Treatment with celecoxib did not significantly alter BP or albuminuria in either female or male SHR. Celecoxib did not change PGs metabolites excretion in male SHR; however, excretion levels of PGEM and 6-keto PGF1α were reduced in female SHR. COX-2 derived PG can also induce oxidative stress. Markers of oxidative stress (thiobarbituric acid reactive substances (TBARs) and H2O2 excretion) were lesser in female SHR versus male SHR. Celecoxib treatment did not significantly change markers of oxidative stress in female SHR, however, urinary TBARs excretion was significantly reduced in male SHR after 6 weeks of treatment with celecoxib. Therefore, although celecoxib treatment appears to have distinct effects on prostanoids levels in female SHR vs. males, it is unlikely that COX-2 contributes to established sex differences in BP in SHR.

Attitude and knowledge of isolation in operative field among undergraduate dental students.

OBJECTIVE: The purpose of this study was to evaluate the general attitude of undergraduate dental students toward rubber dam use, specifically focusing on operative procedures before starting to serve community. METHODS: Questionnaires were distributed to undergraduate clinical years' students of two private colleges; Al-Farabi Dental College, Riyadh, KSA and Buraidah Private Colleges, Qassim, KSA. Questions were asked about areas where the students used rubber dam in operative procedures, in which types of caries classes, and in which type of restoration they frequently used the rubber dam. RESULTS: We found that students of both private dental colleges agreed with the opinions that proper isolation cannot be achieved for the restoration of operative procedures without using rubber dam and restoration placed under rubber dam have a greater longevity than those placed without. CONCLUSIONS: Within the limitations of the present study, it can be concluded that the perceptions of dental students on rubber dam need to be improved and strategies should be developed so that this valuable adjunct will comprise one of the indispensable elements of dental care.

Meloxicam fails to augment the reno-protective effects of soluble epoxide hydrolase inhibition in streptozotocin-induced diabetic rats via increased 20-HETE levels.

The pro-inflammatory cyclooxygenase (COX)-derived prostaglandins and the anti-inflammatory cytochrome P450 epoxygenase-derived epoxyeicosatrienoic acids (EETs) play an important role in the regulation of renal injury. The current study examined whether COX inhibition augments the reno-protective effects of increased EETs levels via inhibiting EETs degradation by soluble epoxide hydrolase (sEH) in diabetic rats. Streptozotocin (50mg/kg, i.v) was used to induce diabetes in male Sprague Dawley rats. Rats were then divided into 5 groups (n=6-8); control non diabetic, diabetic, diabetic treated with the sEH inhibitor trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB), diabetic treated with the COX inhibitor meloxicam and diabetic treated with meloxicam plus t-AUCB for 2 months. Glomerular albumin permeability and urinary albumin and nephrin excretion levels were significantly elevated in diabetic rats together with decreased glomerular α3 integrin and nephrin expression levels. Inhibition of sEH reduced glomerular albumin permeability, albumin and nephrin excretion levels and restored the decrease in glomerular α3 integrin and nephrin expression in diabetic rats. Meloxicam failed to reduce renal injury or even to synergize the reno-protective effects of sEH inhibition in diabetic rats. Furthermore, inhibition of sEH reduced the elevation in renal collagen deposition and urinary MCP-1 excretion levels together with a reduction in the number of renal TUNEL positive cells in diabetic vs. control rats (P<0.05). Meloxicam did not reduce renal inflammation or apoptosis in diabetic rats or even exacerbate the anti-inflammatory and anti-apoptotic effects of sEH inhibition. Renal 20-hydroxyeicosatetranoic acid (20-HETE) levels were elevated in diabetic rats and meloxicam further exacerbated this elevation. In conclusion, our study suggests that inhibition of COX failed to provide renal protection or to augment the reno-protective effects of sEH inhibition in diabetic rats, at least in part, via increased inflammatory 20-HETE levels.

Novel molecular triggers underlie valproate-induced liver injury and its alleviation by the omega-3 fatty acid DHA: role of inflammation and apoptosis.

BACKGROUND/AIM: Hepatic injury is a hallmark adverse reaction to Valproate (VPA), a common used drug in the management of numerous CNS disorders, including epilepsy. DHA has a myriad of health benefits, including renal- and hepato-protective effects. Unfortunately, however, the underpinnings of such liver-pertinent VPA- and DHA-actions remain largely undefined. Accordingly, this study attempted to unveil the cellular and molecular triggers whereby VPA evokes, while DHA abates, hepatotoxicity. METHODS: We evaluated activity and/or expression of cellular markers of oxidative stress, inflammation, and apoptosis in rat liver, following treatment with VPA (500 mg/kg/day) with and without concurrent treatment with DHA (250 mg/kg/day) for two weeks. RESULTS AND CONCLUSION: VPA promoted hepatic oxidative stress as evidenced by enhancing activity/expression of NADPH-oxidase and its subunits, a ROS-generator, and by accumulation of lipid-peroxides. Moreover, VPA enhanced hepatic phosphorylation/activation of mitogen-activated protein kinase (MAPK), and expression of cyclooxygenase-2(COX-2), as proinflammatory signals. Besides, VPA promoted hepatocellular apoptosis, as attested by enhanced expression of cleaved caspase-9 and increased number of TUNEL-positive hepatocytes. Lastly, VPA upregulated levels of hypoxia-inducible factor-1-alpha (HIF-1α), a multifaceted modulator of hepatocytic biology, and activity of its downstream antioxidant enzyme heme-oxygenase-1(HO-1). These changes were significantly blunted by co-administration of DHA. Our findings demonstrate that VPA activated NADPH-oxidase and HIF-1α to induce oxidative-stress and hypoxia as initiators of hepatic injury. These changes were further aggravated by up-regulation of inflammatory (MAPK and COX-2) and apoptotic cascades, but could be partly lessened by HO-1 activation. Concurrent administration of DHA mitigated all VPA-induced anomalies.

Hemodynamic responses to acute angiotensin II infusion are exacerbated in male versus female spontaneously hypertensive rats.

We previously reported that male spontaneously hypertensive rats (SHRs) are more sensitive to chronic angiotensin (Ang) II-induced hypertension compared with female rats. This study was designed to test the hypothesis that anesthetized male SHRs are also more responsive to acute Ang II-induced increases in blood pressure and renal hemodynamic changes when compared with female SHRs. Baseline mean arterial pressure (MAP) was higher in male SHRs than in female SHRs (135 ± 2 vs. 124 ± 4 mmHg, P < 0.05). Acute intravenous infusion of Ang II (5 ng/kg/min) for 60 minutes significantly increased MAP to 148 ± 2 mmHg in male SHRs (P < 0.05) without a significant change in MAP in female SHRs. Baseline glomerular filtration rate (GFR) was also higher in male SHRs than in female SHRs (2.6 ± 0.3 vs. 1.3 ± 0.1 mL/min, P < 0.05). Ang II infusion for 60 min significantly decreased GFR in male SHRs (2.0 ± 0.2 mL/min; P < 0.05) without significant changes in urine flow rate, sodium, or chloride excretion. In contrast, Ang II infusion increased GFR in female SHRs (1.9 ± 0.2 mL/min; P < 0.05). The increase in GFR upon Ang II infusion in female SHRs was associated with increases in urine flow rate (4.3 ± 0.3 to 7.1 ± 0.9 µL/min), sodium excretion (0.16 ± 0.04 to 0.4 ± 0.1 µmol/min), and chloride excretion (0.7 ± 0.08 to 1.1 ± 0.1 µmol/min; for all P < 0.05). These findings support the hypothesis that there is sex difference in response to acute Ang II infusion in SHRs with females being less responsive to Ang II-induced elevations in blood pressure and decreases in GFR relative to male SHRs.

Curcumin Attenuates Iron Accumulation and Oxidative Stress in the Liver and Spleen of Chronic Iron-Overloaded Rats.

OBJECTIVES: Iron overload is now recognized as a health problem in industrialized countries, as excessive iron is highly toxic for liver and spleen. The potential use of curcumin as an iron chelator has not been clearly identified experimentally in iron overload condition. Here, we evaluate the efficacy of curcumin to alleviate iron overload-induced hepatic and splenic abnormalities and to gain insight into the underlying mechanisms. DESIGN AND METHODS: Three groups of male adult rats were treated as follows: control rats, rats treated with iron in a drinking water for 2 months followed by either vehicle or curcumin treatment for 2 more months. Thereafter, we studied the effects of curcumin on iron overload-induced lipid peroxidation and anti-oxidant depletion. RESULTS: Treatment of iron-overloaded rats with curcumin resulted in marked decreases in iron accumulation within liver and spleen. Iron-overloaded rats had significant increases in malonyldialdehyde (MDA), a marker of lipid peroxidation and nitric oxide (NO) in liver and spleen when compared to control group. The effects of iron overload on lipid peroxidation and NO levels were significantly reduced by the intervention treatment with curcumin (P<0.05). Furthermore, the endogenous anti-oxidant activities/levels in liver and spleen were also significantly decreased in chronic iron overload and administration of curcumin restored the decrease in the hepatic and splenic antioxidant activities/levels. CONCLUSION: Our study suggests that curcumin may represent a new horizon in managing iron overload-induced toxicity as well as in pathological diseases characterized by hepatic iron accumulation such as thalassemia, sickle cell anemia, and myelodysplastic syndromes possibly via iron chelation, reduced oxidative stress derived lipid peroxidation and improving the body endogenous antioxidant defense mechanism.