The effect of leptin and resveratrol on JAK/STAT pathways and Sirt-1 gene expression in the renal tissue of ischemia/reperfusion induced rats.

OBJECTIVE: Our study aimed to investigate the possible modifying effects of leptin and combined use of resveratrol on rat renal I/R injury and their relationship on signal pathways and apoptosis-related mechanisms. BACKGROUND: Renal ischemia-reperfusion (I/R) injury is an important cause of acute renal failure. METHODS: Male Sprague Dawley rats were divided into 5 groups: Control, I/R, I/R+leptin, I/R+resveratrol and I/R+leptin+resveratrol. Leptin (10 µg/kg BW) was administered (i.p.) 30 min prior to I/R. Resveratrol was administered by gavage at 20 mg/kg BW per d for 12 d prior to I/R. The left renal artery was exposed to 1 h of ischemia and 1 h of reperfusion. RESULTS: Resveratrol treatment alone increased TNF-α, TNF-α R1, NF-κB, SIRT-1, STAT1 and STAT3 mRNA levels and decreased caspase 3 protein levels. Leptin treatment alone significantly decreased the caspase 3 protein levels. The combined use of resveratrol and leptin significantly increased STAT3, and caspase 3 mRNA levels, and decreased the caspase 3 protein levels. Apoptosis was significantly decreased especially in the leptin and leptin+resveratrol groups. CONCLUSION: The present study suggest that a combined use of resveratrol and leptin has preventive and regulatory effects on renal I/R injury; the mechanism involves decreasing apoptosis, likely by altering the JAK/STAT pathway and SIRT1 expression (Fig. 8, Ref. 24).

Effects of ceranib-2 on cell survival and TNF-alpha in colon cancer cell line.

OBJECTIVE: The aim of this study was to investigate the effects of a novel anti-cancer drug, ceranib-2, which targets the acid ceramidase, in human colon cancer cell line. MATERIALS AND METHODS: The cell lines were treated with 50 µM of ceranib-2. Relative mRNA expression of TNF-alpha, TNF-R1 and ASAH were assessed by quantitative RT-PCR. RESULTS: Ceranib-2 reduced cell viability in a dose-dependent manner and the apoptotic values of cells following treatment with the dose of 50 µM were reduced significantly both at 24 h and 48 h compared to the control cells (p < 0.001). TNF-alpha receptor 1 (TNF-R1) mRNA levels were reduced significantly in the cell lines treated with both 25 µM and 50 µM of ceranib-2 for 24 h compared to the control cells (p < 0.05), whereas the difference between the treatment and the control cell lines diminished at 48 h. The human acid ceramidase gene (ASAH) mRNA levels were significantly higher in the cell lines treated with 50 µM of ceranib-2 for 48 h than in the other cell lines (p < 0.001). CONCLUSION: The study shows that ceranib-2 increased apoptosis by inducing ASAH expression and reduced TNF-R1 expression in human colon cancer cell lines in a dose and time-dependent manner (Fig. 3, Ref. 17).

Leptin receptor (Ob-R) mRNA expression and serum leptin concentration in patients with colorectal and metastatic colorectal cancer.

The objective of the present study was to investigate the effect of leptin on the progression of colorectal carcinoma to metastatic disease by analyzing the serum leptin concentration and Ob-R gene expression in colon cancer tissues. Tissue samples were obtained from 31 patients who underwent surgical resection for colon (18 cases) and metastatic colon (13 cases) cancer. Serum leptin concentration was determined by an enzyme-linked immunosorbent assay (ELISA) and Ob-R mRNA expression by real-time polymerase chain reaction (RT-PCR) for both groups. ELISA data were analyzed by the Student t-test and RT-PCR data were analyzed by the Mann-Whitney U-test. RT-PCR results demonstrated that mRNA expression of Ob-R in human metastatic colorectal cancer was higher than in local colorectal cancer tissues. On the other hand, mean serum leptin concentration was significantly higher in local colorectal cancer patients compared to patients with metastatic colorectal cancer. The results of the present study suggest a role for leptin in the progression of colon cancer to metastatic disease without weight loss. In other words, significantly increased Ob-R mRNA expression and decreased serum leptin concentration in patients with metastatic colon cancer indicate that sensitization to leptin activity may be a major indicator of metastasis to the colon tissue and the determination of leptin concentration and leptin gene expression may be used to aid the diagnosis.

Leptin receptor (Ob-R) mRNA expression and serum leptin concentration in patients with colorectal and metastatic colorectal cancer

The objective of the present study was to investigate the effect of leptin on the progression of colorectal carcinoma to metastatic disease by analyzing the serum leptin concentration and Ob-R gene expression in colon cancer tissues. Tissue samples were obtained from 31 patients who underwent surgical resection for colon (18 cases) and metastatic colon (13 cases) cancer. Serum leptin concentration was determined by an enzyme-linked immunosorbent assay (ELISA) and Ob-R mRNA expression by real-time polymerase chain reaction (RT-PCR) for both groups. ELISA data were analyzed by the Student t-test and RT-PCR data were analyzed by the Mann-Whitney U-test. RT-PCR results demonstrated that mRNA expression of Ob-R in human metastatic colorectal cancer was higher than in local colorectal cancer tissues. On the other hand, mean serum leptin concentration was significantly higher in local colorectal cancer patients compared to patients with metastatic colorectal cancer. The results of the present study suggest a role for leptin in the progression of colon cancer to metastatic disease without weight loss. In other words, significantly increased Ob-R mRNA expression and decreased serum leptin concentration in patients with metastatic colon cancer indicate that sensitization to leptin activity may be a major indicator of metastasis to the colon tissue and the determination of leptin concentration and leptin gene expression may be used to aid the diagnosis.

The effects of PDE5 inhibitory drugs on renal ischemia/reperfusion injury in rats.

The aim of the present study was to evaluate the effects of phosphodiesterase type 5 (PDE5) inhibitory drugs, Tadalafil and Sildenafil, on inducible NOS (iNOS), endothelial NOS (eNOS) and p53 genes expressions and apoptosis in ischemia/reperfusion (I/R) induced oxidative injury in rat renal tissue. Eighty Sprague-Dawley rats (300-350 g) were divided into four groups. In ischemia/reperfusion group, rats were subjected to renal ischemia by clamping the left pedicle for 60 min, and then reperfused for 90 min. On the other hand, in other two groups the rats were individually pretreated with Tadalafil and Sildenafil 1 h before the induction of ischemia. Malondialdehyde (MDA) is determined in renal tissue homogenates by high-performance liquid chromatography, the number of apoptotic cell were calculated by TUNEL method and p53 and eNOS expression were detected with immunohistochemistry. On the other hand, myeloperoxidase (MPO) levels were measured by spectrophotometric method and the mRNA level of iNOS in renal tissue was determined by Real-time PCR (RT-PCR). Our results indicate that MDA and MPO levels were increased in the I/R group than those in the control group. Both Tadalafil and Sildenafil treatment decreased the MDA levels in ischemia/reperfusion group, whereas this effect was more potent with Sildenafil. RT-PCR results showed that, iNOS gen expression increased in the I/R group, but decreased in the PDE5 inhibitory drugs treated group. Apoptotic cells, eNOS levels and p53 positive cells were also decreased in PDE5 inhibitory drugs treated group. We suggest that Tadalafil and Sildenafil have beneficial effects against I/R related renal tissue injury and this protective effect is clearer for Sildenafil than Tadalafil.

Perioperative immunonutrition ameliorates the postoperative immune depression in patients with gastrointestinal system cancer (prospective clinical study in 42 patients).

Cancer surgery is a major challenge for patients to develop immune depression in postoperative period. Several cytokines can depress immune cell subpopulations. Increased cytokine response after surgery is assumed to arise mainly from lipooxygenase pathway acting on membrane arachidonic acid. Therefore; investigators focused their efforts to alter the membrane fatty acid profile by changing the nutritional regimen with epsilon-3 fatty acid supplementation and encouraging results were obtained after surgery. Despite the theoretical and clinical advantage of enteral nutrition many surgeons remain committed to parenteral nutrition for feeding of patients due to maintain bowel rest and fear of anastomosis leakage at the postoperative period. Several studies investigating role of the postoperative immunonutrition reported that beneficial immunological changes were associated with reduction of infectious complications. Interestingly; these findings were observed at least five days after the surgery in which the highest incidence of complications was seen. In this prospective study including 42 patients eligible for curative gastric or colon cancer surgery; we investigated the beneficial effect of enteral immunonutrition (EEN) compared to total parenteral hyperalimentation (TPN) beginning from the preoperative period. Cortisol and CRP levels as stress parameters significantly increased one day after surgery in both groups but they rapidly returned to (on POD1) preoperative baseline level in EEN group whereas these values remained high in the TPN group. Additionally a significant decrease in natural killer (NK) cells and CD8+ levels were observed in both groups. However they recovered on POD3 in EEN group and on POD6 in TPN group. CD4+ subset remained almost same as preoperative value in the TPN group whereas it increased from (%) 40.14 to 46.40, 51.29 and 54.7 on PO 6th hr, POD3 and POD6 in the EEN group. Our findings suggest that preoperative nutrition via the enteral route provided better regulation of postoperative immune system restoration than parenteral nutrition. On the basis of our findings we recommend enteral immunonutrition to be started at the preoperative period rather than postoperatively before a major operation whenever the enteral route is feasible.

Effect of leptin on renal ischemia-reperfusion damage in rats.

Tumor necrosis factor-alpha (TNF-alpha) has been established as an important mediator in renal ischemia-reperfusion (I/R) injury. Leptin, a product of the ob gene, has been known to exhibit cytoprotective effects on renal tissue, but its effect on renal tissue TNF-alpha level after renal I/R injury in rats remains unknown. The purpose of the study was to evaluate the effects of leptin on renal tissue TNF-alpha, malondialdehyde (MDA), protein carbonyls (PCs) and total sulfydryl group (SH) levels, and plasma nitrite levels after renal I/R injury in rats. The animals were divided into three groups: control, I/R and I/R+leptin. Rats were subjected to renal ischemia by clamping the left pedicle for 45 min, and then reperfused for 1 h. The I/R+leptin group was pretreated intraperitoneally with leptin (10 microg/kg) 30 min before the induction of ischemia. Our results indicate that MDA, TNF-alpha levels, and PCs were significantly higher in the I/R group than those in the control group (p < 0.05). The administration of leptin decreased these parameters (p < 0.05) significantly. The SH level was observed to significantly decrease after I/R injury when compared to the control group (p < 0.05). Leptin treatment significantly increased tissue SH and plasma nitrite levels when compared to the I/R group (p < 0.05). Plasma nitrite levels did not change significantly in I/R when compared to the control. These results suggest that leptin could exert a protective effect on I/R induced renal damage by decreasing TNF-alpha levels and increasing nitrite level.

Lidocaine-containing Euro-Collins solution prevents renal injury in the isolated perfused canine kidney exposed to prolonged cold ischemia.

Previous studies have reported a decreased incidence of delayed graft function after cadaveric transplantation with the use of lidocaine pretreatment of the donor. We evaluated the effects of lidocaine on prolonged cold ischemia and reperfusion injury in a canine model of isolated kidney perfusion (IPK). The purpose of this study was to evaluate the renal function of isolated perfused canine kidneys after 48 h of cold storage with Euro-Collins (EC) solution or EC solution plus lidocaine. Isolated perfused canine kidneys were randomized into four groups which contained six kidneys: I) cold flush with EC solution and immediately reperfused, II) cold flush with EC solution plus lidocaine and immediately reperfused, III) 48 h of cold storage with EC and reperfusion, IV) 48 h of cold storage with EC solution plus lidocaine and reperfusion. The measured renal functions were glomerular filtration rate, urine production, perfusate flow, urinary lactic dehydrogenase (ULDH), Na reabsorptive capacity, and tissue MDA levels. Histological examination was performed after reperfusion. The tubular functions of kidneys preserved with EC solution containing lidocaine were better when compared with the kidneys preserved with EC alone. Tubular injury marker levels (ULDH) in group IV were significantly lower than in group III and lidocaine also reduced lipid peroxidation during reperfusion. This is in agreement with the histological results. The results of the present study can be taken as evidence of the cytoprotective effect of lidocaine, which may therefore be accepted as a useful agent for kidney preservation.

Diagnostic value of interleukin-6 and C-reactive protein in acute appendicitis.

The aim of this study is prospectively to evaluate the serum C-reactive protein (CRP) and interleukin-6 (IL-6) levels in detection of acute appendicitis in patients with right iliac fossa pain. Data were collected in prospective manner on 102 consecutive patients with right iliac fossa pain. Laparotomy was performed for suspected acute appendicitis for 55 of the 102 patients, of whom 49 patients had appendicitis, 6 patients non-appendicitis (NA), and the other 47 patients had nonspecific abdominal pain (NSAP) and they did not undergo operation. Among those with appendicitis 31 had acute appendix (AA), 8 had gangrenous appendix (GA), and 10 had perforated appendix (PA). The WBC and CRP the mean (SEM) values were significantly different in AA, GA, and PA groups compared with NSAP and NA groups (P < 0.05). Although the mean IL-6 levels were significantly different only in PA group than the others groups (P < 0.05). The sensitivity and specificity of serum CRP measurements were calculated as 96% and 87%, respectively whereas these were 33% and 83% for IL-6 levels for the diagnosis of the acute appendicitis. As a result, measurement of the CRP levels and WBC have an additional diagnostic value on the diagnosis of the acute appendicitis but determination of IL-6 levels which added to the test combination of WBC and CRP, the sensitivity for the diagnosis of the acute appendicitis was not changed whereas the specificity was decreased to 66%.

L-Arginine-enriched preservation solution decreases ischaemia/reperfusion injury in canine kidneys after long-term cold storage.

BACKGROUND: Kidneys stored hypothermically for transplantation show varying degrees of tissue injury, depending on the duration of preservation. The causes of injury are not entirely clear. We investigated the quality of renal functional recovery in canine kidneys after 72 h hypothermic preservation in custodiol solution or custodiol solution plus L-arginine. METHODS: Kidneys obtained from mongrel dogs, weighing 18-25 kg, were subjected to 72-h cold ischaemia after flushing. Animals were divided into two groups (n=18/group). A flush solution of either custodiol solution or custodiol solution plus L-arginine 1 mmol/l was used for each group. After 72-h cold storage all animals had a contralateral nephrectomy, and autotransplantation was performed to external iliac artery and vein. Survivals were evaluated at 3 days. RESULTS: Renal damage was assessed by kidney function tests, serum creatinine (SCr), blood urea nitrogen (BUN) and light histology. Malondialdehyde (MDA) was measured as an index of lipid peroxidation. SCr and BUN (24, 48 and 72 h) were significantly different from the control and L-arginine groups. Histological damage was less in the L-arginine group. MDA levels were significantly different with the lower levels in the L-arginine group. CONCLUSIONS: On the basis of these data, we concluded that exogenous L-arginine (a substrate for NO synthesis) has a beneficial and protective effect on long-term (72 h) hypothermic ischaemical damage in canine kidneys.

Clonidine pretreatment inhibits stress-induced gastric ulcer in rats.

UNLABELLED: We studied the effects of clonidine (0.5 mg/kg) on hormonal stress response and antioxidant enzymes cold restraint-induced gastric lesions in rats. Rats in the study group were given 0.5 mg/kg intraperitoneal clonidine (n = 12), whereas the control group received 0.5 mL/kg intraperitoneal isotonic sodium chloride solution (n = 9). Animals were then subjected to immobilization at 4 degrees C in restraining devices for 4 h after a starvation period of 24 h. Gastric lesion index, gastric tissue malondialdehyde activity, and plasma cortisol concentrations were assayed. Histopathologic examination demonstrated a stress ulcer index of 3.17+/-0.92 mm in the clonidine group and 14.0+/-3.22 mm in the control group (P<0.05). The tissue malondialdehyde concentrations were slightly higher in the control group than in the clonidine group, but the differences were not statistically significant (P>0.05). Plasma cortisol levels were lower in the clonidine group (P<0.05). We concluded that clonidine attenuated the tissue damage and stress response in stress-induced gastric ulceration. IMPLICATIONS: Stressful circumstances can cause stomach ulcers, which can bleed, exposing patients to potentially life-threatening complications. In the present animal study, we showed that clonidine, a routinely available medication, may be useful in preventing stress-induced stomach ulcers.

Cyclosporine nephrotoxicity in the ischemic kidney and the protective effect of pentoxifylline--a study in the rat.

In order to prevent cyclosporine nephrotoxicity in the ischemic kidney, pentoxifylline was used in a rat model. Seventy-two rats were divided into six groups according to treatment after right nephrectomy: Group I was the control, group II was treated with 25 mg/kg cyclosporine, group III underwent renal ischemia for 45 min, group IV was given 25 mg/kg cyclosporine and subjected to renal ischemia, and group V was subjected to renal ischemia and given 45 mg/kg pentoxifylline (repeated at 12, 36, and 48 hr), group VI underwent renal ischemia and was then given both cyclosporine and pentoxifylline. BUN, creatinine, and potassium levels were significantly elevated 24 hr after cyclosporine (group II), ischemia (group III), and cyclosporine and ischemia (group IV). Sodium levels remained unaffected. BUN levels normalized in all but groups III and IV after 48 hr. Creatinine levels normalized in all but group IV after 48 hr. Creatinine clearance fell in all groups and remained low even after 48 hr. Pentoxifylline prevented dramatic rises in BUN and creatinine and levels nearly normalized after 48 hr. It also histologically prevented extensive tissue damage seen after ischemia. In conclusion, pentoxifylline has a protective effect upon the kidney when subjected to cyclosporine in the presence of ischemia.