Reoxygenation with 100% Oxygen Following Hypoxia in Mice Causes Apoptosis.

After hypoxia, reoxygenation with air is the consensus treatment for full-term neonates; however, the effect of hyperoxic reoxygenation of adults is unknown. The present study was designed to investigate the effects of reoxygenation with 100% oxygen after hypoxia on inflammation and apoptosis in mice. Eight-week-old mice were either subjected to hypoxia in 8% oxygen for 30 min or air served as controls. Following hypoxia, mice underwent reoxygenation for 30 min with 21% or 100% oxygen. Tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), caspase-3 and brain derived neurotrophic factor (BDNF) mRNA study and histopathological study were performed. Reoxygenation with 100% oxygen significantly increased TNF-α (2.5 h after hypoxia), IL-1ß (5 h after hypoxia), caspase-3 (8 h after hypoxia) mRNA levels in the whole brain compared with 21% oxygen, and significantly decreased erythropoietin mRNA expression compared with 21% oxygen 9 h after reoxygenation. However, reoxygenation with 100% oxygen and 21% oxygen significantly decreased BDNF mRNA levels compared with control air group. There were no clear abnormal findings showing neuronal death among the three groups. Reoxygenation with 100% oxygen after hypoxia induced inflammation and apoptosis in adult mice. Therefore, these results suggest that the reoxygenation with 100% oxygen after hypoxia has harmful effects on adult brain as well as on neonatal brain.

Effects of sevoflurane exposure during late pregnancy on brain development of offspring mice.

BACKGROUND: Exposure to some anesthetic agents during the fetal period has been shown to induce neurodegeneration or learning deficits in animal models. Sevoflurane is one of the most prevalent general anesthetics; however, the influence of sevoflurane at a clinically relevant concentration on the developing fetal brain remains unknown. OBJECTIVE: We investigated whether a single sevoflurane exposure during the fetal period would affect neuronal development and learning/memory ability in mice. METHODS: Pregnant mice at gestational day 17 were anesthetized with 1.5% sevoflurane in 50% oxygen for 6 h. Mice in the control group were exposed in 50% oxygen without sevoflurane. Pups of some mice in both groups subsequently were delivered early by cesarean section and whole fetal brains were excised. The rest of the pups were delivered naturally at gestational day 20 and were maintained for 8 weeks. The mRNA expression levels of caspase-3, brain derived neurotrophic factor (BDNF), nerve growth factor (NGF), and LIM kinase-1 (LIMK-1) were measured in fetal whole brain and 8-week-old hippocampus sections. Synaptophysin protein in adult hippocampus was assessed immunochemically. In addition, 8-week-old mice were subjected to the radial maze test. RESULTS: No significant difference between sevoflurane and control groups regarding mRNA expression levels of all targets was seen, nor was there an obvious change in synaptophysin protein expression. The results of the maze test revealed that the each-day performance ratios (the rate of errors) of the sevoflurane group were not altered as compared with the control group. CONCLUSIONS: These results suggest that the exposure during late pregnancy to a clinically relevant concentration of sevoflurane does not affect neuronal development and learning/memory ability of offspring mice.

T-5224, a selective inhibitor of c-Fos/activator protein-1, improves survival by inhibiting serum high mobility group box-1 in lethal lipopolysaccharide-induced acute kidney injury model.

BACKGROUND: Sepsis is a potentially fatal syndrome mediated by an early [e.g., tumor necrosis factor-alpha (TNF-α)] and late [high mobility group box-1 (HMGB-1)] proinflammatory cytokine response to infection. Sepsis-induced acute kidney injury (AKI) is associated with a high mortality. C-Fos/activator protein-1 (AP-1) controls the transactivation of proinflammatory cytokines via AP-1 binding in the promoter region. T-5224 is a de novo small molecule inhibitor of c-Fos/AP-1 that controls gene expression of multiple proinflammatory cytokines. We investigated whether T-5224, a selective inhibitor of c-Fos/AP-1, improves survival in lethal lipopolysaccharide (LPS)-induced AKI by inhibiting early (TNF-α) and late (HMGB-1) proinflammatory cytokine response. METHODS: Mice were divided into four groups (control, LPS, LPS + T-5224, and T-5224 only). Control mice were administered polyvinylpyrrolidone (PVP) solution orally, immediately after intraperitoneal (i.p.) saline injection. LPS mice were administered PVP solution orally immediately after i.p. LPS (10 mg/kg) injection. LPS + T-5224 mice were administered T-5224 orally (300 mg/kg) immediately after i.p. LPS injection. T-5224 mice were administered T-5224 orally (300 mg/kg) after i.p. saline injection. Serum concentrations of TNF-α, HMBG-1, and interleukin (IL)-10 were measured by enzyme-linked immunosorbent assay (ELISA). Serum blood urea nitrogen (BUN) and creatinine concentrations were commercially analyzed. Finally, histological examination was performed on the kidney. RESULTS: Treatment with T-5224 decreased serum TNF-α and HMGB-1 levels and increased survival after LPS injection. Furthermore, T-5224 treatment decreased serum BUN and creatinine concentrations but increased serum IL-10 concentration. LPS-induced pathological changes in kidney were attenuated by T-5224 treatment. CONCLUSIONS: These results suggest that T-5224, a selective inhibitor of c-Fos/AP-1, inhibits expression of early and late proinflammatory cytokines, protecting mice from LPS-induced lethality. T-5224 is a potential approach for decreasing lethality in sepsis-induced AKI.

Early postnatal repeated maternal deprivation causes a transient increase in OMpg and BDNF in rat cerebellum suggesting precocious myelination.

Repetitive maternal deprivation (MD) of neonatal rats during early life is known as one of the strongest stressors to pre-weaned animals. There is increasing evidence that the cerebellum is involved in cognition and emotion. In the present study, we examined how neurotrophic factors and myelin-associated molecules and their receptors (NGF, BDNF, OMgp, TrkA, TrkB, p75 NTR, and NgR) in the cerebellum are affected by early postnatal maternal separation. Rat pups were separated from their mothers for 3h/day during postnatal days (PND) 10-15. At PND 16 and 30, the levels of mRNA and protein in the cerebellum were determined using real-time PCR and Western blot analysis. Cerebellar mRNA and protein levels of BDNF, TrkB, and OMgp were significantly increased in MD rats at PND 16. However, by PND 30 these variables normalized to control levels. In contrast, the levels of mRNA and protein for NGF, TrkA, p75 NTR, and NgR were unchanged at both ages examined. Transient enhancement of neurotrophic system and myelin-associated molecule expression may cause interference of normal development of the cerebellum such as precocious myelination, which may lead to functional and cognitive deficits later in life.

Short-term ethanol exposure causes imbalanced neurotrophic factor allocation in the basal forebrain cholinergic system: a novel insight into understanding the initial processes of alcohol addiction.

Alcohol ingestion affects both motor and cognitive functions. One brain system that is influenced by ethanol is the basal forebrain (BF) cholinergic projection system, which projects to diverse neocortical and limbic areas. The BF is associated with memory and cognitive function. Our primary interest is the examination of how regions that receive BF cholinergic projections are influenced by short-term ethanol exposure through alterations in the mRNA levels of neurotrophic factors [nerve growth factor/TrkA, brain-derived neurotrophic factor/TrkB, and glial-derived neurotrophic factor (GDNF)/GDNF family receptor α1]. Male BALB/C mice were fed a liquid diet containing 5 % (v/v) ethanol. Pair-fed control mice were maintained on an identical liquid diet, except that the ethanol was isocalorically substituted with sucrose. Mice exhibiting signs of ethanol intoxication (stages 1-2) were used for real-time reverse transcription-polymerase chain reaction analyses. Among the BF cholinergic projection regions, decreased levels of GDNF mRNA and increased levels of TrkB mRNA were observed in the basal nucleus, and increased levels of TrkB mRNA were observed in the cerebral cortex. There were no significant alterations in the levels of expression of relevant neurotrophic factors in the septal nucleus and hippocampus. Given that neurotrophic factors function in retrograde/anterograde or autocrine/paracrine mechanisms and that BF cholinergic projection regions are neuroanatomically connected, these findings suggested that an imbalanced allocation of neurotrophic factor ligands and receptors is an initial phenomenon in alcohol addiction. The exact mechanisms underlying this phenomenon in the BF cholinergic system are unknown. However, our results provide a novel notion for the understanding of the initial processes in alcohol addiction.

Early postnatal maternal separation causes alterations in the expression of ß3-adrenergic receptor in rat adipose tissue suggesting long-term influence on obesity.

The effects of early postnatal maternal deprivation on the biological characteristics of the adipose tissue later in life were investigated in the present study. Sprague-Dawley rats were classified as either maternal deprivation (MD) or mother-reared control (MRC) groups. MD was achieved by separating the rat pups from their mothers for 3h each day during the 10-15 postnatal days. mRNA levels of mitochondrial uncoupling protein 1 (UCP-1), ß3-adrenergic receptor (ß3-AR), and prohibitin (PHB) in the brown and white adipose tissue were determined using real-time RT-PCR analysis. UCP-1, which is mediated through ß3-AR, is closely involved in the energy metabolism and expenditure. PHB is highly expressed in the proliferating tissues/cells. At 10 weeks of age, the body weight of the MRC and MD rats was similar. However, the levels of the key molecules in the adipose tissue were substantially altered. There was a significant increase in the expression of PHB mRNA in the white adipose tissue, while the ß3-AR mRNA expression decreased significantly, and the UCP-1 mRNA expression remained unchanged in the brown adipose tissue. Given that these molecules influence the mitochondrial metabolism, our study indicates that early postnatal maternal deprivation can influence the fate of adipose tissue proliferation, presumably leading to obesity later in life.

D-ribose ameliorates cisplatin-induced nephrotoxicity by inhibiting renal inflammation in mice.

Cisplatin is one of the most potent chemotherapeutic anticancer drugs, but it can produce side effects such as nephrotoxicity. Inflammatory cytokines, chemokines and adhesion molecules have important roles in the pathogenesis of cisplatin-induced nephrotoxicity. D-Ribose is a naturally occurring five-carbon monosaccharide that is found in all living cells, and has anti-inflammatory effects in renal ischemia/reperfusion injury. The purpose of this study was to determine the protective effects of D-ribose on cisplatin-induced nephrotoxicity. Forty-eight mice were randomly divided into four groups: control, cisplatin, cisplatin + ribose, and ribose. Mice were given cisplatin (20 mg/kg body weight, intraperitoneally) with or without D-ribose (400 mg/kg body weight, intraperitoneally, immediately after cisplatin injection). At 72 h after cisplatin injection, we measured serum and renal tumor necrosis factor (TNF)-α and renal monocyte chemoattractant protein (MCP)-1 concentrations by enzyme-linked immunosorbent assay; renal expression of intercellular adhesion molecule (ICAM)-1 mRNA by real-time polymerase chain reaction; serum blood urea nitrogen and creatinine; and histological changes. Cisplatin increased serum and renal TNF-α concentrations, renal MCP-1 concentration, and renal ICAM-1 mRNA expression. Treatment with D-ribose attenuated the increase in serum and renal TNF-α concentrations, renal MCP-1 concentration, and renal ICAM-1 mRNA expression. Consequently, cisplatin-induced renal dysfunction and renal tubular necrosis were attenuated by D-ribose treatment. This is believed to be the first time that protective effects of D-ribose on cisplatin-induced nephrotoxicity via inhibition of inflammatory reactions have been investigated. Thus, D-ribose may become a new therapeutic candidate for the treatment of cisplatin-induced nephrotoxicity.

Curcumin ameliorates cisplatin-induced nephrotoxicity by inhibiting renal inflammation in mice.

Inflammatory mechanisms may play an important role in the pathogenesis of cisplatin-induced nephrotoxicity. Curcumin is an orange-yellow polyphenol present in curry spice and has anti-inflammatory and antioxidant effects. The purpose of this study was to determine the protective effects of curcumin on cisplatin-induced nephrotoxicity. Mice were randomly divided into four groups: control, cisplatin, cisplatin + curcumin and curcumin. Mice were given cisplatin (20 mg/kg body weight, intraperitoneally) with or without curcumin treatment (100 mg/kg body weight, intraperitoneally, immediately after cisplatin injection). Serum and renal tumor necrosis factor (TNF)-alpha and renal monocyte chemoattractant protein (MCP)-1 concentrations, intercellular adhesion molecule-1 (ICAM-1) mRNA expression in kidney, renal function and histological changes were determined 72 h after cisplatin injection. Serum TNF-alpha concentration in the cisplatin + curcumin group significantly decreased compared with that in the cisplatin group. Renal TNF-alpha and MCP-1 concentrations and ICAM-1 mRNA expression in kidney in the cisplatin + curcumin group also significantly decreased compared with those in the cisplatin group. Consequently, cisplatin-induced renal dysfunction and renal tubular necrosis scores were attenuated by curcumin treatment. These results indicate that curcumin acts to reduce cisplatin-induced nephrotoxicity through its anti-inflammatory effects. Thus, curcumin may become a new therapeutic candidate for the treatment of cisplatin-induced nephrotoxicity.

Differential effects of neonatal maternal separation on the expression of neurotrophic factors in rat brain. II: Regional differences in the cerebellum versus the cerebral cortex.

This study was conducted in order to examine the effects of early postnatal maternal separation stress on the age-dependent fluctuations in the expression levels of neurotrophic factor ligands and receptors in the developing cerebellum. Wistar rats were separated from their mothers for 3 h each day during postnatal days (PND) 10 to 15. The expression level of mRNA for brain-derived neurotrophic factor (BDNF), tyrosine kinase receptor B (TrkB), insulin-like growth factor-1 (IGF-1), and type-1 IGF receptor (IGF-1R) were evaluated in the cerebellum on PND16, 20, 30, and 60 with real-time RT-PCR. The mRNA levels of cerebellar BDNF in maternally separated rats were increased on PND16, while the other variables showed no significant alterations at any of the time points examined. However, the effects of an identical maternal separation on the cerebral cortex were previously reported to be completely different. These results indicate regional differences in the responses of neurotrophic factor ligands/receptors between the cerebellum and cerebral cortex. Given that neurotrophic factors play important roles in brain development, alterations in these factors may interrupt normal brain development and ultimately, lead to functional disruptions.

The effects of a selective inhibitor of c-Fos/activator protein-1 on endotoxin-induced acute kidney injury in mice.

BACKGROUND: Sepsis has been identified as the most common cause of acute kidney injury (AKI) in intensive care units. Lipopolysaccharide (LPS) induces the production of several proinflammatory cytokines including tumor necrosis factor (TNF)-alpha, a major pathogenetic factor in septic AKI. c-Fos/activator protein (AP)-1 controls the expression of these cytokines by binding directly to AP-1 motifs in the cytokine promoter regions. T-5224 is a new drug developed by computer-aided drug design that selectively inhibits c-Fos/AP-1 binding to DNA. In this study, we tested whether T-5224 has a potential inhibitory effect against LPS-induced AKI, by suppressing the TNF-alpha inflammatory response and other downstream effectors. METHODS: To test this hypothesis, male C57BL/6 mice at 7 weeks old were divided into three groups (control, LPS and T-5224 groups). Mice in the control group received saline intraperitoneally and polyvinylpyrrolidone solution orally. Mice in the LPS group were injected intraperitoneally with a 6 mg/kg dose of LPS and were given polyvinylpyrrolidone solution immediately after LPS injection. In the T-5224 group, mice were administered T-5224 orally at a dose of 300 mg/kg immediately after LPS injection. Serum concentrations of TNF-alpha, interleukin (IL)-1beta, IL-6 and IL-10 were measured by ELISA. Moreover, the expression of intercellular adhesion molecule (ICAM)-1 mRNA in kidney was examined by quantitative real-time RT-PCR. Finally, we evaluated renal histological changes. RESULTS: LPS injection induced high serum levels of TNF-alpha, IL-1beta and IL-6. However, the administration of T-5224 inhibited the LPS-induced increase in these cytokine levels. The serum levels of IL-10 in the LPS group and T-5224 group were markedly elevated compared with the control group. T-5224 also inhibited LPS-induced ICAM-1 mRNA expression. Furthermore histological studies supported an anti-inflammatory role of T-5224. CONCLUSIONS: In endotoxin-induced AKI, T-5224 inhibited the production of TNF-alpha and other downstream effectors. In contrast, T-5224 did not inhibit IL-10, an anti-inflammatory cytokine. These data support that the use of T-5224 is a promising new treatment for septic kidney injury.

D-allose ameliorates cisplatin-induced nephrotoxicity in mice.

Cisplatin (cis-diamminedichloroplatinum II) is a potent antineoplastic agent widely used to treat various forms of cancer. However, its therapeutic use is limited because of dose-dependent nephrotoxicity. Inflammatory mechanisms may play an important role in the pathogenesis of cisplatin nephrotoxicity. D-allose is an aldo-hexose present in nature that recently has been demonstrated to inhibit production of inflammatory mediators in septic kidneys. The purpose of this study was to determine the protective effects of D-allose on cisplatin-induced nephrotoxicity. Cisplatin (20 mg/kg) was administered by intraperitoneal injection to mice in the cisplatin group and the cisplatin plus D-allose group, as was normal saline to control group mice. D-allose was intraperitoneally administered immediately after cisplatin injection. Serum and renal tumor necrosis factor (TNF)-alpha concentrations, renal monocyte chemoattractant protein-1 (MCP-1; a chemotactic factor for monocytes), renal function, histological changes and renal cortex neutrophil infiltration were determined 72 h after cisplatin injection. The serum TNF-alpha concentration in the cisplatin plus D-allose (400 mg/kg body weight) group significantly decreased in comparison with that in the cisplatin group. The renal TNF-alpha and MCP-1 concentrations in the cisplatin plus D-allose group significantly decreased in comparison with those in the cisplatin group. Neutrophil infiltration in the cisplatin plus D-allose group was significantly lower than that in the cisplatin group. Cisplatin-induced renal dysfunction and renal tubular injury scores were attenuated by D-allose treatment. These results reveal that D-allose attenuates cisplatin-induced nephrotoxicity by suppressing renal inflammation. Hence, D-allose may become a new therapeutic candidate for treatment of cisplatin-induced nephrotoxicity.

T-5224, a selective inhibitor of c-Fos/activator protein-1, attenuates lipopolysaccharide-induced liver injury in mice.

The effect of T-5224, a selective inhibitor of c-Fos/activator protein (AP)-1, on lipopolysaccharide (LPS) induced liver injury was examined in mice. Administration of LPS (10 mg kg(-1), i.p.) markedly increased serum levels of tumor necrosis factor-alpha (TNFα), high mobility group box 1 (HMGB1), alanine aminotransferase/aspartate aminotransferase (ALT/AST), liver tissue levels of macrophage-inflammatory protein-1 alpha (MIP-1α) and monocyte chemoattractant protein-1 (MCP-1), as well as hepatic necrosis and inflammation, leading to 67 % lethality. Administration of T-5224 (300 mg kg(-1), p.o.) after intraperitoneal injection of LPS imparted appreciable protection against acute elevations in serum levels of TNFα, HMGB1, ALT/AST as well as in liver tissue levels of MIP-1α and MCP-1, and reduced the lethality (27 %). These data indicate that T-5224 ameliorates liver injury and improves survival through decreasing production of proinflammatory cytokines and chemokines in endotoxemic mice.

Neonatal repetitive maternal separation causes long-lasting alterations in various neurotrophic factor expression in the cerebral cortex of rats.

AIMS: This study was carried out to examine the effects of early postnatal maternal separation stress on the development of the cerebral cortex with respect to time-dependent fluctuations of neurotrophic factor ligand and receptor expression. MAIN METHODS: Wistar rats were separated from their mothers for 3h per day during postnatal days (PND) 10 to 15. The cerebral cortex was analyzed by real-time RT-PCR for the evaluation of the expression of mRNA for brain-derived neurotrophic factor (BDNF), TrkB, insulin-like growth factor-1 (IGF-1), and type 1 IGF receptor (IGF-1R) on PND16, 20, 30, and 60. KEY FINDINGS: The expression of these neurotrophic factor ligands and receptors in the cerebral cortex was enhanced on PND16 and PND20, and then it returned to baseline levels on PND30. By PND60, however, the expression levels were attenuated. SIGNIFICANCE: The important implication of this study is the persistent abnormal fluctuation of neurotrophic factor expression for a prolonged period, triggered even after the brain growth spurt. Given that neurotrophic factors play important roles in brain development, it can be speculated that the altered expression of these factors induced by maternal separation may interrupt normal brain development and ultimately lead to functional disruption. However, the possibility of such changes leading to various functional disruptions and the underlying mechanisms involved require further study.

Erythropoietin attenuates isoflurane-induced neurodegeneration and learning deficits in the developing mouse brain.

OBJECTIVES: To examine whether recombinant erythropoietin (rEPO) attenuates neurodegeneration and the learning disability induced by isoflurane with the postnatal day 7 (P7) mice. BACKGROUND: Some of general anesthetic agents induce neurodegeneration in developing brain. Several drugs, but not rEPO, were reported as candidates for the prevention of or treatment for neurodegeneration. METHOD AND MATERIALS: We divided P7 mice into three groups at random. One group (IE group) was exposed to 6-h isoflurane (1.0%) after 50,000 IU·kg(-1) rEPO administered subcutaneously. The second group (I) was exposed to isoflurane in the same manner as IE group except saline instead of rEPO. The third group (E) was exposed to air after rEPO administered. The mice were assigned to the radial arm maze on four consecutive days from P56 (day 1) to P59 (day 4). We divided the number of errors each day by that of day 1 to establish each-day performance ratio. After the test, neurodegenerative change in the hilus of dentate gyrus was assessed using Nissl staining. RESULTS: In radial maze test, the performance ratios of day 3 (mean ± sd) were 0.3 ± 0.2 (P < 0.05, vs I group), 0.8 ± 0.5, and 0.6 ± 0.2 in IE, I, and E groups, respectively, while those of day 4 were 0.3 ± 0.1 (P < 0.05), 0.8 ± 0.5, and 0.3 ± 0.2 (P < 0.05), respectively. The histopathological study revealed that in IE group the degenerative neuronal change was attenuated compared with I group. CONCLUSIONS: These results suggested that rEPO attenuated isoflurane-induced neurodegeneration.

[Preoperative evaluation, management and outcome in the elderly patient].

Two principles should be kept in mind when performing preoperative evaluation of the elderly patient. First, we should suspect the disease processes commonly associated with aging. Second, we should assess the degree of functional reserve of specific, pertinent organ systems. Preoperative risk assessment is focused on detailed review from anamnesis and physical examination together with the assessment of functional status. Especially, it is important to examine the cardiovascular and respiratory functions in the elderly patient. Further, this also includes assessment of consumed drugs, physiological function, cognitive function, competency, availability of social support, and sign of depression. Surgical risk and outcome in the elderly patient depend primarily on four factors: age, the patient's physiological status and coexisting disease, whether the surgery is elective or urgent, and the type of procedures.

Atrial natriuretic peptide enhances recovery from ischemia/reperfusion-induced renal injury in rats.

Recovery from ischemic acute kidney injury requires the replacement of damaged tubular cells. This repair process involves epidermal growth factor (EGF) synthesized in medullary the thick ascending limbs (mTAL) of Henle. Atrial natriuretic peptide (ANP), a hormone synthesized by the cardiac atria, increases glomerular filtration rate and renal medullary blood flow. However, the effects of ANP on renal recovery after I/R-induced renal injury remain unclear. We therefore examined whether human ANP enhances recovery from I/R-induced renal injury by reducing damage to EGF-producing kidney cells in a rat model. Male Wistar rats weighing 200-240 g were observed for 48 h after reperfusion following 45-min renal ischemia. Rats were intravenously administered alpha-human ANP (alpha-hANP) at 0.2 microg/kg/min beginning immediately after ischemia and continuing for 2 h after reperfusion. Outer medullary blood flow (OMBF), EGF mRNA, serum blood urea nitrogen (BUN) and creatinine levels as indicators of glomerular function were measured, while urinary N-acetyl beta-D-glucosaminidase (NAG) was used as a specific indicator of proximal tubular function. OMBF was increased by alpha-hANP after reperfusion and maintained significantly higher mRNA level of EGF in the kidney 24 h after reperfusion. I/R-induced increases in serum concentrations of BUN and creatinine and urinary concentrations of NAG were also reduced by alpha-hANP, with improved histopathological changes, including acute tubular necrosis at 24-48 h after reperfusion. This report is the first to demonstrate that alpha-hANP accelerates recovery following renal ischemic insult by reducing the damage to EGF-producing kidney cells.

Role of hypoxia-inducible factor 1alpha in T cells as a negative regulator in development of vascular remodeling.

BACKGROUND AND PURPOSE: Recent studies have shown that the cellular immune response in the development of vascular remodeling modulates the resulting pathological alterations. We show that hypoxia-inducible factor 1 (Hif-1) (specifically expressed in T cells) is involved in the immune response to vascular remodeling that accompanies arteriosclerosis. METHODS AND RESULTS: To study the role of T cells in the development of vascular remodeling, femoral arterial injury induced by an external vascular polyethylene cuff was examined in mice lacking Hif-1 (specifically in T cells). We found that cuff placement caused prominent neointimal hyperplasia of the femoral artery in Hif-1- (T-cell)-deficient mice compared with that in control mice and that infiltration of inflammatory cells at the adventitia was markedly increased in the mutant mice. Studies to clarify the mechanism of augmented vascular remodeling in the mutant mice showed enhanced production of cytokines by activated T cells and augmented antibody production in response to a T-dependent antigen in the mutant mice. CONCLUSIONS: The results of this study revealed that Hif-1alpha in T cells plays a crucial role in vascular inflammation and remodeling in response to cuff injury as a negative regulator of T cell-mediated immune response. Potential new therapeutic strategies that target Hif-1alpha are described.

Protective action of D-ribose against renal injury caused by ischemia and reperfusion in rats with transient hyperglycemia.

Hyperglycemia amplifies the inflammatory state after ischemia/reperfusion (I/R), and activated neutrophils have been implicated in the development of I/R-induced renal injuries. D-ribose is a naturally occurring monosaccharide found in all living cells. In this study, we examined whether D-ribose attenuates I/R-induced renal injury by reducing neutrophil activation in rats with transient hyperglycemia. Male Wistar rats were divided into sham (n = 24), control (n = 64), and D-ribose (n = 32) groups. Rats received intraperitoneal injection of glucose (3 g/kg) 30 min before induction of ischemia to induce transient hyperglycemia. Anesthetized rats underwent right nephrectomy and subsequent occlusion of the left renal artery and vein for 45 min. D-ribose (400 mg/kg) was intravenously administered 30 min before induction of ischemia. D-ribose significantly reduced the degree of the I/R-induced increases in renal concentrations of cytokine-induced neutrophil chemoattractant-1 (a chemotactic factor for the activation of neutrophils and chemotaxis to the site of injury) and myeloperoxidase (an indicator of neutrophils infiltration). D-ribose also reduced the I/R-induced increases in serum levels of blood urea nitrogen and creatinine, and improved histological changes, including acute tubular necrosis in the corticomedullary junction fields. These results indicate that D-ribose reduces the I/R-induced acute renal injury in rats with transient hyperglycemia, probably by reducing neutrophil activation. D-ribose might thus be useful for surgical procedures, such as renal transplant surgery, under hyperglycemia.

Hypoxia-inducible factor-1 alpha has a key role in hypoxic preconditioning.

Sublethal hypoxia induces tolerance to subsequent hypoxic insults in a process known as hypoxic preconditioning (HP). Hypoxia-inducible factor-1 alpha (HIF-1 alpha) is a key transcription protein involved in the mechanism of HP. In this study, we investigated the effects of HP on tissue oxygenation and expression of HIF-1 alpha gene targets in the brain using neural cell-specific HIF-1 alpha-deficient mice. The animals were exposed to 8% oxygen for 3 hours. Twenty-four hours later, the oxygen partial pressure (pO(2)) of brain tissue and gene expression were measured during hypoxia. HP improved the pO(2) of brain tissue during subsequent hypoxia with upregulated inducible nitric oxide synthase in wild-type mice, whereas HP had no detectable effect in the mutant mice. Our results indicate that the protective effects of HP may be partially mediated by improving tissue oxygenation via HIF-1 alpha and inducible nitric oxide synthase.

D-ribose attenuates ischemia/reperfusion-induced renal injury by reducing neutrophil activation in rats.

The ischemia/reperfusion (I/R) represents a common pathological mechanism that causes renal injuries. A monosaccharide D-allose has been shown to inhibit neutrophil activation, which is involved in the I/R-induced organ injuries. We therefore examined the role of D-ribose in the I/R-induced renal injury using a rat model. D-ribose, a monosaccharide found in all living cells, serves as a key component of adenosine-5'-triphosphate and nicotinamide adenine dinucleotide. Male Wistar rats were divided into the sham, control and D-ribose groups. In the control and D-ribose groups, rats were subjected to 45 min of left renal ischemia, followed by 24 h of reperfusion, while the I/R procedure was not performed in the sham group. Rats were intravenously administered D-ribose (sham group and D-ribose group, 400 mg/kg) or saline (control group) 30 min before ischemia. Blood urea nitrogen (BUN), serum creatinine and urinary N-acetyl beta-D-glucosaminidase (NAG) were measured as indicators of glomerular function and proximal tubular function. We also measured cytokine-induced neutrophil chemoattractant-1 (CINC-1) and myeloperoxidase concentrations to assess neutrophil activation and infiltration, respectively. The tissue sections were scored to evaluate the tubular injury. In the control group, BUN, creatinine, NAG, CINC-1, myeloperoxidase, histological severity score, and number of infiltrating neutrophils were increased following I/R insult, as compared with the sham group. Such increases in biochemical markers, severity score, and infiltrating neutrophils were significantly inhibited in the D-ribose group. Thus, D-ribose ameliorates the I/R-induced renal injury probably by inhibiting neutrophil activation, and may be useful in attenuating the renal injury associated with renal ischemia.