Hydrogen sulfide upregulates hypoxia inducible factors and erythropoietin production in chronic kidney disease induced by 5/6 nephrectomized rats.

INTRODUCTION: In end stage renal disease )ESRD(, reduced EPO production resulted in decreased oxygen diffusion that cause Hypoxia-inducible factors (HIFs) stabilization. The mechanism of beneficial effects of H2S in chronic kidney disease (CKD) is the aim of the present study to examine the effects of the H2S donor sodium hydrosulfide (NaHS) on renal function parameters, oxidative stress indices and expression levels of HIF-2α gene and erythropoietin protein in 5/6 nephrectomy-induced chronic renal failure in rats. METHODS AND MATERIALS: Male rats were assigned into 3 groups (n = 8): Sham, CKD and NaHS groups. In the CKD group, 5/6 nephrectomy was performed. In the sham group, rats were anesthetized but 5/6 nephrectomy was not induced. In the NaHS group, 30 µmol/L of NaHS in drinking water for 8 weeks was adminstrated 4 weeks after 5/6 nephrectomy induction. At the end of the 12 week, blood and renal tissues were taken to evaluate renal function parameters, oxidative stress indices and expression levels of HIF-2α gene and erythropoietin protein. RESULTS: The induction of 5/6 nephrectomy significantly caused renal dysfunction, oxidative stress, increased HIF-2α gene expression and decreased erythropoietin levels in renal tissue samples. NaHS administration resulted in a marked improvement in renal function and oxidative stress indicators, a marked reduction in HIF-2α gene expression as well as an increase in erythropoietin protein levels in comparison with the CKD group. CONCLUSION: In this study, regional hypoxia and oxidative stress in CKD, may cause the stabilization of the HIFs complexes, although erythropoietin synthesis was not increased due to destructive effects of CKD on the kidney tissues. Administration of NaHS caused up-regulating HIF-erythropoietin signaling pathway.

A comparison between centrally and systemically administered erythropoietin on kidney protection in a model of fixed-volume hemorrhagic shock in male rats.

BACKGROUND: In this study, a comparison between centrally and systemically administered erythropoietin (EPO) was performed on nephroprotection during hemorrhagic shock (HS) in male rats. METHODS: Male rats were allocated into four experimental groups. (1) Sham; a guide cannula was inserted into the left lateral ventricle and other cannulas were placed into the left femoral artery and vein. (2) HS; stereotaxic surgery was done to insert a cannula in the left lateral ventricle and after a 7-day recovery; hemorrhagic shock and resuscitation were performed. (3) EPO-systemic; the procedure was the same as the HS group except that animals received 300 IU/kg erythropoietin into the femoral vein immediately before resuscitation. (4) EPO-central; animals was treated with erythropoietin (2 IU/rat) into the left lateral ventricle before resuscitation. Arterial oxygen saturation (SaO2) was measured during experiments. Urine and renal tissue samples were stored for ex-vivo indices assessments. RESULTS: Erythropoietin (systemically/centrally administered) significantly improved SaO2, renal functional and oxidative stress parameters and decreased renal inflammatory (TNF-α and IL-6) mRNA expression compared to the HS group. EPO-treated groups showed a decrease in active form of caspase-3 protein level and an increase in autophagy activity in comparison with the HS group. CONCLUSION: Considering the fact that the effective dose of systemic EPO (300 IU/kg) was roughly 50 times higher than that of central administration (2 IU/rat), centrally administered EPO was accompanied by more advantageous consequences than systemic way. EPO is likely to act as a neuro-modulator or neuro-mediator in the central protection of organs including the kidneys.

The effects of CORM3 or NaHS on the oxidative stress caused by chronic kidney disease in rats: potential interaction between CO and H2S signaling pathway.

Neurotoxicity is implicated as a severe complication of chronic kidney disease (CKD). Accumulation of urea and other toxic compounds leads to oxidative stress, inflammation and destruction of the blood-brain barrier. Carbon monoxide (CO) and hydrogen sulfide (H2S) have been shown to have anti-inflammatory, anti-apoptotic, and anti-proliferative properties. The aims of the present study were evaluated the protective effects of CO-releasing molecule (CORM3) and H2S donor (NaHS) on oxidative stress and neuronal death induced by CKD in the hippocampus and prefrontal cortex by considering interaction between CO and H2S on CBS expression. CORM3 or NaHS significantly compensated deficits in the antioxidant defense mechanisms, suppressed lipid peroxidation and reduced neuronal death in hippocampus and prefrontal cortex and improvement the markers of renal injury that induced by CKD. In addition, CORM3 or NaHS significantly improved CBS expression which were reduced by CKD. However, improving effects of CORM3 on antioxidant defense mechanisms, lipid peroxidation, neuronal death, renal injury and CBS expression were prevented by amino-oxy acetic acid (AOAA) (CBS inhibitor) and reciprocally improving effects of NaHS on all above indices were prevented by zinc protoporphyrin IX (Znpp) (HO-1 inhibitor). In conclusion, this study demonstrated that formation of CO and H2S were interdependently improved CKD-induced oxidative stress and neuronal death, which is may be through increased expression of CBS.

Nephroprotection through Modifying the Apoptotic TNF-α/ERK1/2/Bax Signaling Pathway and Oxidative Stress by Long-term Sodium Hydrosulfide Administration in Ovalbumin-induced Chronic Asthma.

Asthma is one of the most common respiratory diseases in the world. Nevertheless, it is reported that inflammation induced by asthma is not only restricted to the lung and may cause damaging effects on remote organs. Therefore, this study was designed to investigate the beneficial effects of long-term sodium hydrosulfide (NaHS) administration on lung inflammation and oxidative stress markers to protect the kidney during chronic asthma. BALB/c mice were divided into three groups (n = 5-7): control, asthma and NaHS. Except the control group, sensitization and challenge were performed with ovalbumin. The NaHS group intraperitoneally received 14 µmol/kg NaHS 30 min before each challenge. 24 h after the last challenge, samples of bronchoalveolar lavage fluid (BALF), plasma, lung and kidney tissues were collected. NaHS administration significantly decreased total white blood cell count, percentages of eosinophils, neutrophils and macrophages and increased percentage of lymphocytes. Administration of NaHS considerably decreased the levels of BALF interleukin-13, plasma tumor necrosis factor-alpha (TNF-α), lung malondialdehyde (MDA) and lung phosphorylated nuclear factor-kappa B (p-NF-κB) expression and scores of peribronchial inflammatory cell infiltration, goblet cell hyperplasia and subepithelial fibrosis and increased the activity of lung superoxide dismutase (SOD). The MDA levels and expressions of p-ERK1/2 and Bax were decreased and SOD activity and expressions of Bcl-2 and p-Akt were significantly increased in kidney tissues by NaHS administration. Administration of NaHS decreased renal oxidative stress indices and reduced apoptosis by the inhibition of TNF-α/ERK1/2/Bax. Therefore, H2S may have an essential role in renal protection during asthma.

Long-term NaHS administration reduces oxidative stress and apoptosis in a rat model of left-side varicocele.

The main aim of this study was to assay the testicular H2 S levels in the varicocele rat model and then to investigate the protective effects of NaHS on morphometric changes, sperm parameters, oxidative stress and apoptosis markers in rat's testis. D,L-propargylglycine (PAG) was administrated to show the effects of cystathionine γ-lyase enzyme (CSE) inhibition in the varicocele. Rats were assigned to four groups: (a) Sham, (b) varicocele, (c) varicocele + PAG and (d) varicocele + NaHS. Animals in varicocele + NaHS group received 30 µmol/L NaHS in drinking water for 56 days. In the varicocele + PAG group, animals received PAG 19 mg/kg twice a week. Morphometric assessment, oxidative stress markers, testicular H2 S levels, sperm parameters, TUNEL assay and expression of Bax/Bcl2 were evaluated at the end of experiment. Testicular H2 S levels were significantly decreased in varicocele group. NaHS significantly improved sperm parameters, morphometric characteristics and oxidative stress compared to varicocele group. Oxidative stress status deteriorated in the PAG group compared to the varicocele group. This study showed that a low testicular H2 S level might play a critical role in male infertility. Thus, NaHS administration may be a promising treatment strategy for male infertility in varicocele. In addition, CSE may not be the only important enzyme in testicular H2 S production.

Protective effects of ascorbic acid and calcitriol combination on airway remodelling in ovalbumin-induced chronic asthma.

Context: Airway remodelling is one of the most refractory problems in asthma. According to the critical roles of oxidative stress and inflammation in airway remodelling, it is supposed that ascorbic acid and calcitriol have beneficial effects. However, a combination of antioxidants may be more effective for asthma therapy.Objective: This study investigated the protective effects of ascorbic acid in combination with calcitriol on airway remodelling in ovalbumin (OVA)-induced chronic asthma.Materials and methods: BALB/c mice were assigned into seven groups: (1) Control; (2) Asthma; (3) Ineffective C (orally 39 mg/kg ascorbic acid); (4) Ineffective D (intraperitoneally 1.5 µg/kg calcitriol); (5) Effective C (orally 130 mg/kg ascorbic acid); (6) Effective D (intraperitoneally 5 µg/kg calcitriol); (7) Combination (orally 39 mg/kg ascorbic acid + intraperitoneally 1.5 µg/kg calcitriol). All animals were sensitized and challenged with OVA except in the control group (normal saline). In all treatment groups, mice were administrated vitamins 30 min before each challenge (three times per week for 8 consecutive weeks).Results: In comparison with the asthma group, co-administration of ineffective doses of ascorbic acid and calcitriol led to the decreased levels of IL-13 (50.5 ± 1.85 vs. 42.13 ± 0.37 pg/mL, p = 0.02) and IgE (58.74 ± 0.43 vs. 45.78 ± 2.05 ng/mL, p = 0.003) as well as the reduction of goblet hyperplasia and subepithelial fibrosis (5 vs. 1 score, p = 0.001 and 5 vs. 2 score, p = 0.001, respectively).Discussion and conclusions: Combination of ascorbic acid with calcitriol in ineffective doses improves airway remodelling due to additive effects possibly through reduction of oxidative stress and inflammation. This study provides a scientific basis for further research and clinical applications of ascorbic acid and calcitriol and can be generalized to the broader pharmacological studies.

The Impact of Sex Differences on Renal Protective Effects of Lipopolysaccharide Preconditioning in Septic Shock.

BACKGROUND: Induction of septic shock by lipopolysaccharide (LPS) may lead to acute renal failure. The present study aimed to investigate the impact of sex differences on the effectiveness of low-dose LPS preconditioning (LPS-PC) on LPS-induced acute renal failure in rats. METHODS: This study was conducted at Tehran University of Medical Sciences, in 2017. A total of 48 Wistar rats were equally divided into two groups of male and female rats. The rats in each group were then allocated to three groups (n=8 per group), namely control, septic shock, and LPS-PC group. A high dose of LPS was administered for septic shock induction. LPS-PC was induced by injecting LPS before sepsis induction. The effect of sex differences on renal functional indices, renal oxidative stress markers, plasma tumor necrosis factor-α level, and renal histological changes was evaluated. Data were analyzed using two-way ANOVA followed by Tukey's post hoc test. RESULTS: In the septic shock groups, renal functional parameters (creatinine [Cr] and blood urea nitrogen [BUN]) were increased in both sexes. However, the increase was more significant in male rats (male rats: Cr=2.14±0.13, BUN=81±4.15; female rats: Cr=1.64±0.12, BUN=50±2.7). LPS-PC reduced these indices in both sexes (male rats: Cr=1.24±0.03, BUN=57±4.1; female rats: Cr=0.86±0.02, BUN=30.31±2.25). Renal superoxide dismutase (SOD) activity (male rats: 11.54±1.34, female rats: 24.4±2.04) and catalase (CAT) activity (male rats: 15±1.74, female rats: 25.75±1.97) were significantly higher in the female septic group. LPS-PC significantly increased SOD (male rats: 25.7±2.45, female rats: 42.6±3.31) and CAT (male rats: 37.25±2.34, female rats: 59.21±3.29) activities in renal tissue samples in the LPS-PC group in both sexes compared to the septic groups. In the LPS groups, plasma tumor necrosis factor-α (male rats: 375±25.65, female rats: 285.45±25.94) were significantly higher than in the LPS-PC groups (male rats: 250±21.35, female rats: 121±24.14). CONCLUSION: Male rats were more susceptible to sepsis-induced renal damage. LPS-PC had protective effects on the LPS-induced renal injury, and these effects were most prominent in female rats.

Long-term exercise restores hydrogen sulfide in the kidney and contributes to exercise benefits in 5/6 nephrectomized rats.

Physical exercise is shown to have protective effects on chronic kidney disease (CKD). CKD itself is associated with a reduction in renal hydrogen sulfide (H2S) concentration. This study was designed to investigate whether protective effects of exercise in 5/6 nephrectomized (5/6 NX) rats is associated with H2S levels in the kidney? Twenty four male Wistar rats weighing 250-300 g were assigned into 4 groups: 1- Sham 2- Sham exercise 3-5/6 NX 4-5/6 NX+exercise. To induce CKD, 4 days after removing upper and lower one-third parts of the left kidney, total right nephrectomy was performed. In the Sham groups, anesthesia and surgery were performed like the other groups without removal of the kidney mass. Exercise was performed by treadmill at a speed of 18 m/min for 8 weeks. At the end of the twelfth week, blood and kidney samples were collected to measure renal function (levels of plasma urea and creatinine), oxidative stress markers (renal MDA level and SOD activity), and histological indices. Eight weeks exercise significantly improved serum creatinine, BUN, renal MDA level, SOD activity, renal sympathetic nerve activity (RSNA), hypertension, and renal histology in addition to renal H2S level compared to the 5/6 NX group. The results suggest that regular exercise improves renal oxidative status and ameliorates renal damage, hypertension, and RSNA in 5/6 nephrectomized rats. These improvements by exercise might be associated with the increase in renal H2S level.

Additional effects of erythropoietin pretreatment, ischemic preconditioning, and N-acetylcysteine posttreatment in rat kidney reperfusion injury

Background/aim: Since the nature of ischemia/reperfusion (IR)-induced tissue damage is multifactorial and complex, in the current study, the effects of multiple treatment strategies via concomitant administration of erythropoietin (EPO) and N-acetylcysteine (NAC) with an ischemic preconditioning (IPC) regimen on renal IR injury were examined. Materials and methods: Thirty male Wistar rats were subjected to bilateral occlusion of the renal pedicles for 50 min followed by reperfusion. EPO (1000 IU/kg) was administered for 3 days, as well as IPC before the IR and NAC (150 mg/kg) administration for 4 days after IR. The animals were randomly allocated into 6 groups (n = 5): sham, IR, EPO+IR, IPC+IR, NAC+IR, and EPO+IPC+NAC+IR. Kidney tissues and blood samples were obtained for oxidative stress, proinflammatory cytokines, and renal functional evaluations. Results: IR caused significant inflammatory response, oxidative stress, and reduced renal function. Treatment with EPO, IPC, and NAC or a combination of two of them attenuated renal dysfunction and reduced the oxidative stress and inflammatory markers. Rats treated with the combination of EPO, IPC, and NAC showed a higher degree of protection compared to the other groups. Conclusion: These results showed that concomitant administration of EPO and IPC along with posttreatment NAC may have additive beneficial effects on kidney IR injury during IR-induced acute renal failure.

Resuscitative therapy with erythropoietin reduces oxidative stress and inflammatory responses of vital organs in a rat severe fixed-volume hemorrhagic shock model.

Hemorrhagic shock (HS) still has a high mortality rate and none of the known resuscitative regimens completely reverse its adverse outcomes. This study investigated the effects of different models of resuscitative therapy on the healing of organ damage in a HS model. Male Wistar rats were randomized into six groups: Sham, without HS induction; HS, without resuscitation; HS+Blood, resuscitation with the shed blood; HS+Blood+NS, resuscitation with blood and normal saline; HS+Blood+RL, resuscitation with blood and Ringer's lactate; EPO, erythropoietin was added to the blood and RL. Blood and urine samples were obtained 3 h after resuscitation. Kidney, liver and brain tissue samples were harvested for multiple organ failure evaluation. Survival rate was the highest in the Sham, EPO and HS+Blood+RL groups compared to others. Plasma creatinine concentration, ALT, AST, urinary NAG activity and renal NGAL mRNA expression significantly increased in the HS+Blood+RL group compared to the Sham group. There was a significant increase in tissue oxidative stress markers and pro-inflammatory cytokines in HS+Blood+RL group compared to the Sham rats. EPO had more protective effects on multiple organ failure compared to the HS+Blood+RL group. EPO, as a resuscitative treatment, attenuated HS-induced organ damage. It seems that it has a potential to be attractive for clinical trials.

Up-regulation of nitric oxide synthases by erythropoietin alone or in conjunction with ischemic preconditioning in ischemia reperfusion injury of rat kidneys.

The effects of erythropoietin (EPO) alone or in conjunction with ischemic preconditioning (IPC) on nitric oxide synthase as well as comparing their effects on oxidative stress and proinflammatory cytokines are studied. Rats underwent bilateral renal ischemia of 50 min followed by 24 h reperfusion. They were administered EPO (5000 iu/kg i.p.) and/or subjected to IPC and sacrificed after 24 h, then plasma and tissue samples were obtained. Treatment of either EPO or IPC and their combination attenuates oxidative stress, decreases histological damages, inhibits proinflammatory response, and up-regulates iNOS and eNOS gene expression compared to IR group. In addition, EPO+IPC and EPO treatment produced significant up-regulation in iNOS gene expression compared to IPC group. In IPC and EPO+IPC groups, more powerful effect on up-regulation of eNOS gene expression was shown compared to EPO group. Our findings suggest that treatment with EPO or IPC and their combination improve renal function and preserve tubular damage induced by IR injury. These advantageous effects were closely related to reducing oxidative stress, suppressing proinflammatory response and enhancing generation of NO. IPC was more powerful in enhancement of eNOS gene expression compared to EPO that was more effective in increasing of iNOS gene expression.

Hind limb perconditioning renoprotection by modulation of inflammatory cytokines after renal ischemia/reperfusion.

Purpose Renal ischemia/reperfusion (I/R) injury is a common clinical problem associated with significant mortality and morbidity. One newly described strategy to reduce this damage is remote perconditioning (RPEC), in which short-time ischemia of a limb during renal ischemia reduces the I/R-induced kidney injury. This study aimed to assess whether RPEC confer protection through changes in pro-inflammatory mediators. Methods Rats were subjected to right nephrectomy and randomized into: sham (no intervention), I/R (subjected to 45-min left renal ischemia) and RPEC group (subjected to four cycles of 5-min I/R of the femoral artery administered during renal ischemia). After 24-h, blood, urine, and kidney samples were collected. Biochemical indicators of renal dysfunction were measured in the cases of Neutrophil gelatinase-associated lipocalin (NGAL), and N-acetyl-B-diglucosaminidase (NAG) activity. Inflammatory cytokines [interleukin (IL)-6 and tumor necrosis factor-alpha, TNF-α] expression in the renal tissues as well as Periodic acid-Schiff stained histological sections were evaluated. Results I/R resulted in renal dysfunction, as evidenced by higher renal NGAL expression and urinary NAG activities. This was accompanied by increased TNF-α and IL-6 expressions as well as histological changes in this group. However, RPEC improved renal histology and function compared with the I/R group. Furthermore, the RPEC group showed decreases in TNF-α and IL-6 expression. Conclusions These results suggest that RPEC reduces the dysfunction and injury associated with I/R of the kidney. This technique reduced the pro-inflammatory cytokine in the kidney. RPEC could be a promising strategy against I/R-induced acute kidney injury partly by down-regulation of inflammatory mediators.

Angiotensin II in paraventricular nucleus contributes to sympathoexcitation in renal ischemia-reperfusion injury by AT1 receptor and oxidative stress.

BACKGROUND: To investigate the effect of angiotensin II (Ang II) in the hypothalamic paraventricular nucleus (PVN) on renal ischemia-reperfusion (IR) injury and to assay the role of renal sympathetic nerve activity (RSNA). METHODS: A cannula was inserted into the right side PVN in Sprague-Dawley rats for microinjection of Ang II (3, 30, and 300 ng); Ang II AT1 receptor antagonist, losartan (0.3 µg); and the superoxide dismutase (SOD) mimetic, tempol (20 nmol) before right side nephrectomy. After 1 wk, renal IR injury was induced by clamping the left renal artery for 45 min, and then reperfusion for 3 or 24 h. The extent of renal damage was determined by evaluation of renal functional indices. RSNA was recorded in all groups. Oxidative stress indices (SOD activity and malondialdehyde levels) were assayed in the PVN. RESULTS: Microinjection of pharmacologic doses of Ang II into the PVN exaggerated renal IR injury, increased RSNA and oxidative stress in the PVN dose dependently. The effects of Ang II (3 ng) was prevented by pretreatment with losartan into the PVN. Furthermore, the deleterious effects of Ang II on renal IR injury, RSNA, and oxidative stress were abolished by pretreatment with tempol. CONCLUSIONS: These results indicate that the PVN is a responsive site for central Ang II increment damage in renal ischemia-reperfusion injury. We suggested the central effects of Ang II in the PVN on renal IR injury are mediated by AT1 receptors and oxidative stress in the PVN, and the peripheral effects by a sympathetic pathway.

Enhancement of renal oxidative stress by injection of angiotensin II into the paraventricular nucleus in renal ischemia-reperfusion injury.

This study was designed to investigate whether microinjection of angiotensin II (Ang II) into the hypothalamic paraventricular nucleus (PVN) in renal ischemia-reperfusion (IR) injury has any effect on renal oxidative stress and damage through renal sympathetic nerve activity (RSNA). One week before the induction of left renal IR injury, right nephrectomy was performed and a cannula was placed into the right PVN. Rats were then distributed among 4 groups (n = 6); Sham, IR, IR + Ang II, and IR + Ang II + losartan. Renal IR injury was induced by clamping the left renal artery for 45 min followed by 24 h reperfusion. Losartan (0.3 µg) and Ang II (3 ng) were microinjected into the PVN at 20 min and 10 min, respectively, before the induction of IR injury. Ang II increased plasma creatinine, urinary NAG activity, and histological changes, and enhanced RSNA compared with the IR group (p < 0.05). Ang II increased malondialdehyde (MDA) levels and reduced superoxide dismutase (SOD) activity in the kidney compared with IR injury. Losartan caused a reduction in plasma creatinine, urinary NAG activity, histological changes, renal sympathetic nerve activity (RSNA), and renal MDA levels, and increased renal SOD activity compared with the IR group (p < 0.05). These data demonstrated that increased RSNA activity, via microinjection of Ang II into the PVN, exaggerated renal IR injury by inducing oxidative stress in the kidney.

Functional near-infrared spectroscopy based blood pressure variations and hemodynamic activity of brain monitoring following postural changes: A systematic review.

Postural change from supine or sitting to standing up leads to displacement of 300 to 1000 mL of blood from the central parts of the body to the lower limb, which causes a decrease in venous return to the heart, hence decrease in cardiac output, causing a drop in blood pressure. This may lead to falling down, syncope, and in general reducing the quality of daily activities, especially in the elderly and anyone suffering from nervous system disorders such as Parkinson's or orthostatic hypotension (OH). Among different modalities to study brain function, functional near-infrared spectroscopy (fNIRS) is a neuroimaging method that optically measures the hemodynamic response in brain tissue. Concentration changes in oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (HHb) are associated with brain neural activity. fNIRS is significantly more tolerant to motion artifacts compared to fMRI, PET, and EEG. At the same time, it is portable, has a simple structure and usage, is safer, and much more economical. In this article, we systematically reviewed the literature to examine the history of using fNIRS in monitoring brain oxygenation changes caused by sudden changes in body position and its relationship with the blood pressure changes. First, the theory behind brain hemodynamics monitoring using fNIRS and its advantages and disadvantages are presented. Then, a study of blood pressure variations as a result of postural changes using fNIRS is described. It is observed that only 58 % of the references concluded a positive correlation between brain oxygenation changes and blood pressure changes. At the same time, 3 % showed a negative correlation, and 39 % did not show any correlation between them.

The effect of adipose-derived mesenchymal stem cell transplantation on ovarian mitochondrial dysfunction in letrozole-induced polycystic ovary syndrome in rats: the role of PI3K-AKT signaling pathway.

OBJECTIVE: The present study aimed to elucidate how mesenchymal stem cells (MSCs) application could efficiently attenuate pathological changes of letrozole-induced poly cystic ovary syndrome (PCOS) by modulating mitochondrial dynamic via PI3K-AKT pathway. METHODS: Thirty-two female rats were randomly divided into four experimental groups: Sham, PCOS, PCOS + MSCs, and PCOS + MSCs + LY294002. The Sham group received 0.5% w/v carboxymethyl cellulose (CMC); the PCOS group received letrozole (1 mg/kg, daily) in 0.5% CMC for 21 days. Animals in the PCOS + MSCs group received 1 × 106 MSCs/rat (i.p,) on the 22th day of the study. In the PCOS + MSCs + LY294002 group, rats received LY294002 (PI3K-AKT inhibitor) 40 min before MSC transplantation. Mitochondrial dynamic gene expression, mitochondrial membrane potential (MMP), citrate synthase (CS) activity, oxidative stress, inflammation, ovarian histological parameters, serum hormone levels, homeostatic model assessment for insulin resistance (HOMA-IR), insulin and glucose concentrations, p-PI3K and p-AKT protein levels were evaluated at the end of the experiment. RESULTS: PCOS rats showed a significant disruption of mitochondrial dynamics and histological changes, lower MMP, CS, ovary super oxide dismutase (SOD) and estrogen level. They also had a notable rise in insulin and glucose concentrations, HOMA-IR, testosterone level, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels, ovarian malondialdehyde (MDA) content as well as a notable decrease in p-PI3K and p-AKT protein levels compared to the Sham group. In the PCOS + MSCs group, the transplantation of MSCs could improve the above parameters. Administration of LY294002 (PI3K-AKT pathway inhibitor) deteriorated mitochondrial dynamic markers, oxidative stress status, inflammation markers, hormonal levels, glucose, and insulin levels and follicular development compared to the PCOS + MSCs group. CONCLUSIONS: This study demonstrated that the protective effects of MSC transplantation in regulating mitochondrial dynamics, promoting mitochondrial biogenesis, competing with redox status and inflammation response were mainly mediated through the PI3K-AKT pathway in the PCOS model.

Exploring the Therapeutic Potential of Sodium Hydrosulfide in Alleviating Oxidative Stress and Ovarian Dysfunction in a Rat Model of Polycystic Ovary Syndrome.

Background: Oxidative stress is known to play a key role in the occurrence of polycystic ovary syndrome (PCOS) as the most common cause of anovulatory infertility. The purpose of the current study was to investigate whether diminished activity of ovarian enzymes responsible for hydrogen sulfide (H2S) production, cystathionine ß-synthase (CBS), and cystathionine γ-lyase (CSE) contributes to oxidative stress in PCOS. The study also explored whether administration of sodium hydrosulfide (NaSH), an H2S donor, could ameliorate PCOS symptoms by reducing oxidative stress. Methods: The total eighteen rats were randomly assigned into three groups (n=6): control, PCOS, and PCOS+NaSH. PCOS was induced by intramuscular injection of estradiol valerate to induce PCOS in the PCOS and PCOS+NaSH groups. The PCOS+NaSH group received 30 µmol/L of NaSH in drinking water for 27 days after PCOS induction. Ovarian tissue samples were analyzed for oxidative stress indices including malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity. Additional analyses measured H2S levels, CBS, and CSE activity. Results: PCOS induction led to a significant decrease in SOD activity, H2S levels, and CBS and CSE activity, accompanied by a significant increase in MDA levels (p<0.0001). Furthermore, PCOS caused severe histological alterations in the ovaries. However, administration of NaSH effectively restored all measured parameters to pre-PCOS induction levels (p<0.0001). Conclusion: This study showed that the decrease in the activity of H2S-producing enzymes and H2S levels may contribute to oxidative stress in PCOS. Therefore, administration of NaSH as a H2S donor can be considered as a potential therapeutic strategy for PCOS patients.

Remote preconditioning reduces oxidative stress, downregulates cyclo-oxygenase-2 expression and attenuates ischaemia-reperfusion-induced acute kidney injury.

Remote preconditioning (rPeC) is a phenomenon by which short-time intermittent ischaemia-reperfusion (I/R) of a remote organ during ischaemia protects other organs from I/R injury (IRI). The aim of the present study was to investigate the protective effect of rPeC on renal IRI in rats. Rats were subjected to right nephrectomy and randomized as into a sham group (no additional intervention), an I/R group (subjected to 45 min left renal pedicle occlusion) and an rPeC group (subjected to four cycles of 5 min I/R of the left femoral artery administered at the beginning of renal ischaemia). After 24 h, blood, urine and tissue samples were collected. Compared with the sham group, I/R resulted in renal dysfunction, as evidenced by significantly lower creatinine clearance (CCr; 0.52 ± 0.06 vs 0.11 ± 0.02 mL/min, respectively) and higher fractional excretion of sodium (FE(Na) ; 0.80 ± 0.07% vs 2.46 ± 0.20%, respectively). This was accompanied by decreased superoxide dismutase (SOD; 6.9 ± 1.7 vs 26.7 ± 2.7 U/g tissue) and catalase (CAT; 20.2 ± 8.8 vs 32.2 ± 8.7 K/g tissue) activity in the I/R group, as well as decreased levels of reduced glutathione (GSH; 21.7 ± 8.1 vs 81.2 ± 20.2 µmol/g tissue) and increased malondialdehyde levels (MDA; 1.2 to 0.1 vs 0.5 ± 0.2 µmol/100 mg), cyclo-oxygenase (COX)-2 expression and histological damage. In the rPeC group, renal histology and function were significantly improved (CCr 0.32 ± 0.02 mL/min; FE(Na) 1.33 ± 0.12%) compared with the I/R group. Furthermore, compared with the I/R group, the rPeC group exhibited increases in SOD and CAT activity (22.8 ± 3.8 U/g tissue and 21.7 ± 8.6 K/g tissue, respectively), increased GSH levels (74.0 ± 4.9) and decreased MDA levels (1.1 ± 0.3 µmol/100 mg) and COX-2 expression. In conclusion, rPeC appears to exert protective effects against renal IRI. This protection may be a consequence of reductions in lipid peroxidation, intensification of anti-oxidant systems and downregulation of COX-2 expression. A simple approach, rPeC may be a promising strategy for protection against IRI in clinical practice.

Point-of-care salivary oxidative and renal functional markers to assess kidney function in reperfusion-induced acute kidney injury in male rats.

OBJECTIVES: Saliva is one of the most promising body fluids in the research of new biomarker for various diseases diagnosis. However, serial sampling in this condition is very dangerous and pose iatrogenic anemia with blood loss. This study was done to evaluate the cost-effectiveness of point-of-care salivary tests and identify the validity of salivary markers. METHODS: Rats were randomly assigned to four experimental groups: (1) control (2) IR-3 h (3) IR-6 h (4) IR-24 h. Both renal pedicles were occluded for 55 min and then were declamped to allow reperfusion for 3, 6 and 24 h in IR groups. After reperfusion, all rats received pilocarpine 1 mg/kg to collect saliva. Plasma samples were also collected. Renal parameters including Cr, uric acid, and urea, malondialdehyde (MDA) levels, Bax/Bcl2 ratio, nitrite/nitrate ratio, corticosterone levels and oxidant/antioxidant ratio were measured in both plasma and salivary samples. RESULTS: There were significant increased level of renal function parameters, MDA levels, Bax/Bcl2 ratio, nitrite/nitrate ratio and corticosterone in both saliva and plasma. The comparison of above parameters in both saliva and plasma showed significant correlation. CONCLUSIONS: This study demonstrated that concentrations of indices specifically renal functional parameters increase in saliva in the IR-induced kidney injury in male rats and result indicate the potential of saliva as a tool to monitoring AKI. Measurement of salivary parameters may can become reliable diagnostic tests for patients with AKI.

The effect of tannic acid on renal renin-angiotensin signaling pathway in a model of unilateral ureteral obstruction in male Wistar rats.

The purpose of current study was to elucidate polyphenol tannic acid effect on renal function and activity of the renin-angiotensin system after unilateral ureteral obstruction (UUO). Male Wistar rats were divided into three groups of six randomly: 1) Sham, 2) UUO, and 3) UUO + Tannic acid. Rats in the UUO and UUO + Tannic acid groups experienced unilateral ureteral obstruction. In the Sham group, the abdominal cavity was exposed without UUO induction. In the UUO + Tannic acid group, animals received tannic acid (20 mg/kg) intraperitoneally, 6 and 12 h after clamping the left ureter and 6 and 12 h after the right nephrectomy. Blood samples were taken to measure blood urea nitrogen (BUN) and creatinine levels. Kidney tissue samples were obtained for assessment of oxidative stress, inflammatory indices and the levels of renin-angiotensin system components. Tannic acid administration significantly improved UUO-induced kidney dysfunction (serum BUN: 66.42 ± 14.414 mg/dl, p < 0.05; serum creatinine: 1.67 ± 0.258 mg/dl, p < 0.05), oxidative stress (MDA level: 95.29 ± 37.35 µmol/g tissue, p < 0.05; SOD activity: 59.82 ± 13.41 U/g protein, p < 0.01) and inflammation (renal TNF-α: 57.05 ± 15.653 pg/g tissue, p < 0.05; renal IL-6: 117.015 ± 24.076 pg/g tissue, p < 0.001). The treatment caused a reduction in the amount of renal angiotensinogen, renin and ACE genes expression compared to the UUO group (Angiotensinogen: 8.9 ± onefold, p < 0.05, Renin: 6.5 ± 1.14 fold, p < 0.05, ACE: 4.9 ± 0.64 fold, p < 0.05). Angiotensin II type 1 receptor protein levels decreased in the tannic acid-treated rats in comparison with the UUO group (0.61 ± 0.136, p < 0.05). According to the result of the current study, tannic acid considerably attenuated the complications of unilateral ureteral obstruction through renin-angiotensin system modulation. Trial registration: IR.TUMS.MEDICINE.REC.1400.802.