Cardiomyocyte-specific overexpression of GPR22 ameliorates cardiac injury in mice with acute myocardial infarction.

BACKGROUND: The activation of G protein-coupled receptors (GPCR) signaling by external stimuli has been implicated in inducing cardiac stress and stress responses. GPR22 is an orphan GPCR expressed in brains and hearts, while its expression level is associated with cardiovascular damage in diabetes. Previous studies have suggested a protective role of GPR22 in mechanical cardiac stress, as loss of its expression increases susceptibility to heart failure post-ventricular pressure overload. However, the involvement and underlying signaling of GPR22 in cardiac stress response to ischemic stress remains unexplored. METHODS: In this study, we used cultured cells and a transgenic mouse model with cardiomyocyte-specific GPR22 overexpression to investigate the impact of ischemic stress on GPR22 expression and to elucidate its role in myocardial ischemic injury. Acute myocardial infarction (AMI) was induced by left coronary artery ligation in eight-week-old male GPR22 transgenic mice, followed by histopathological and biochemical examination four weeks post-AMI induction. RESULTS: GPR22 expression in H9C2 and RL-14 cells, two cardiomyocyte cell lines, was decreased by cobalt chloride (CoCl2) treatment. Similarly, reduced expression of myocardial GPR22 was observed in mice with AMI. Histopathological examinations revealed a protective effect of GPR22 overexpression in attenuating myocardial infarction in mice with AMI. Furthermore, myocardial levels of Bcl-2 and activation of PI3K-Akt signaling were downregulated by ischemic stress and upregulated by GPR22 overexpression. Conversely, the expression levels of caspase-3 and phosphorylated ERK1/2 in the infarcted myocardium were downregulated with GPR22 overexpression. CONCLUSION: Myocardial ischemic stress downregulates cardiac expression of GPR22, whereas overexpression of GPR22 in cardiomyocytes upregulates Akt signaling, downregulates ERK activation, and mitigates ischemia-induced myocardial injury.

Impaired insulin signaling at the bladder mucosa facilitates metabolic syndrome-associated bladder overactivity in rats with maternal and post-weaning fructose exposure.

BACKGROUND/PURPOSE: Metabolic syndrome (MetS) and overactive bladder might share common pathophysiologies. Environmental fructose exposure during pre- and postnatal periods of rats may program MetS-associated bladder overactivity. We explored the dysregulated insulin signalling at bladder mucosa, as a common mechanism, in facilitating bladder overactivity in rats with MetS induced by maternal and post-weaning fructose diet. METHODS: Male offspring of Sprague-Dawley rats were subject into 4 groups by maternal and post-weaning diets (i.e., Control/Control, Fructose/Control, Control/Fructose and Fructose/Fructose by diets). Micturition behavior was evaluated. Acidic ATP solution was used to elicit cystometric reflex along with insulin counteraction. Concentration-response curves to insulin were plotted. The canonical signalling pathway of insulin was evaluated in the bladder mucosal using Western blotting. Levels of detrusor cGMP and urinary NO2 plus NO3 were measured. RESULTS: Male offspring with any fructose exposure presents traits of MetS and bladder overactivity. We observed all fructose exposure groups have the poor urodynamic response to insulin during ATP solution stimulation and poor insulin-activated detrusor relaxation in organ bath study. Compared to controls, the Control/Fructose and Fructose/Fructose groups showed the increased phosphorylation levels of IRS1 (Ser307) and IRS2 (Ser731); thus, suppressed the downstream effectors and urinary NOx/detrusor cGMP levels. The Fructose/Control group showed the compensatory increase of phospho-AKT (Ser473) and phospho-eNOS/eNOS levels, but decreased in eNOS, phospho-eNOS, urinary NOx, and detrusor cGMP levels. CONCLUSION: Our results show dysregulated insulin signalling at bladder mucosa should be a common mechanism of MetS-associated bladder overactivity programmed by pre-and postnatal fructose diet.

Anomalous AMPK-regulated angiotensin AT1R expression and SIRT1-mediated mitochondrial biogenesis at RVLM in hypertension programming of offspring to maternal high fructose exposure.

BACKGROUND: Tissue oxidative stress, sympathetic activation and nutrient sensing signals are closely related to adult hypertension of fetal origin, although their interactions in hypertension programming remain unclear. Based on a maternal high-fructose diet (HFD) model of programmed hypertension, we tested the hypothesis that dysfunction of AMP-activated protein kinase (AMPK)-regulated angiotensin type 1 receptor (AT1R) expression and sirtuin1 (SIRT1)-dependent mitochondrial biogenesis contribute to tissue oxidative stress and sympathoexcitation in programmed hypertension of young offspring. METHODS: Pregnant female rats were randomly assigned to receive normal diet (ND) or HFD (60% fructose) chow during pregnancy and lactation. Both ND and HFD offspring returned to ND chow after weaning, and blood pressure (BP) was monitored from age 6 to 12 weeks. At age of 8 weeks, ND and HFD offspring received oral administration of simvastatin or metformin; or brain microinfusion of losartan. BP was monitored under conscious condition by the tail-cuff method. Nutrient sensing molecules, AT1R, subunits of NADPH oxidase, mitochondrial biogenesis markers in rostral ventrolateral medulla (RVLM) were measured by Western blot analyses. RVLM oxidative stress was measured by fluorescent probe dihydroethidium and lipid peroxidation by malondialdehyde assay. Mitochondrial DNA copy number was determined by quantitative real-time polymerase chain reaction. RESULTS: Increased systolic BP, plasma norepinephrine level and sympathetic vasomotor activity were exhibited by young HFD offspring. Reactive oxygen species (ROS) level was also elevated in RVLM where sympathetic premotor neurons reside, alongside augmented protein expressions of AT1R and pg91phox subunit of NADPH oxidase, decrease in superoxide dismutase 2; and suppression of transcription factors for mitochondrial biogenesis, peroxisome proliferator-activated receptor γ co-activator α (PGC-1α) and mitochondrial transcription factor A (TFAM). Maternal HFD also attenuated AMPK phosphorylation and protein expression of SIRT1 in RVLM of young offspring. Oral administration of a HMG-CoA reductase inhibitor, simvastatin, or an AMPK activator, metformin, to young HFD offspring reversed maternal HFD-programmed increase in AT1R and decreases in SIRT1, PGC-1α and TFAM; alleviated ROS production in RVLM, and attenuated sympathoexcitation and hypertension. CONCLUSION: Dysfunction of AMPK-regulated AT1R expression and SIRT1-mediated mitochondrial biogenesis may contribute to tissue oxidative stress in RVLM, which in turn primes increases of sympathetic vasomotor activity and BP in young offspring programmed by excessive maternal fructose consumption.

Effects of a quasi-experimental study of using flipped classroom approach to teach evidence-based medicine to medical technology students.

BACKGROUND: Flipped classroom is known to improve learning efficiency and to develop one's ability to apply high-level knowledge. To investigate the effect of flipped classroom approach on teaching evidence-based medicine to medical technology students, we conducted a tailor-made six flipped classroom based EBM courses for medical technology students. METHODS: This study adopted a qusai-experimental design with 62 medical technology interns as the research object. Students in the experimental group attended the flipped classroom course, while students in the control group attended the traditional course. The learning outcomes were evaluated by Fresno test in both groups. Furthermore, to understand student's perceptions on the flipped classroom approach, students in the experimental group were required to fill in a satisfaction survey and answer some open-ended questions. RESULTS: The Fresno test scores of the experimental group were significantly higher than that of the control group. From the results of the satisfaction survey, we know that students were satisfied with this course format. Students claimed that the flipped classroom approach could improve their learning efficiency and the interactions with teacher could help them to think more deeply. CONCLUSIONS: To conclude, most students showed positive attitudes and views on flipped classroom strategy. Moreover, students' questions were solved more effectively during class resulting in an improvement of effectiveness of evidence-based medicine trainings.

Pioglitazone reversed the fructose-programmed astrocytic glycolysis and oxidative phosphorylation of female rat offspring.

Excessive maternal high-fructose diet (HFD) during pregnancy and lactation has been reported to cause metabolic disorders in the offspring. Whether the infant's brain metabolism is disturbed by maternal HFD is largely unknown. Brain energy metabolism is elevated dramatically during fetal and postnatal development, whereby maternal nutrition is a key factor that determines cellular metabolism. Astrocytes, a nonneuronal cell type in the brain, are considered to support the high-energy demands of neurons by supplying lactate. In this study, the effects of maternal HFD on astrocytic glucose metabolism were investigated using hippocampal primary cultures of female infants. We found that glycolytic capacity and mitochondrial respiration and electron transport chain were suppressed by maternal HFD. Mitochondrial DNA copy number and mitochondrial transcription factor A expression were suppressed by maternal HFD. Western blots and immunofluorescent images further indicated that the glucose transporter 1 was downregulated whereas the insulin receptor-α, phospho-insulin receptor substrate-1 (Y612) and the p85 subunit of phosphatidylinositide 3-kinase were upregulated in the HFD group. Pioglitazone, which is known to increase astrocytic glucose metabolism, effectively reversed the suppressed glycolysis, and lactate release was restored. Moreover, pioglitazone also normalized oxidative phosphorylation with an increase of cytosolic ATP. Together, these results suggest that maternal HFD impairs astrocytic energy metabolic pathways that were reversed by pioglitazone.

Pinin protects astrocytes from cell death after acute ischemic stroke via maintenance of mitochondrial anti-apoptotic and bioenergetics functions.

BACKGROUND: Stroke is the second most common cause of deaths worldwide. After an ischemic stroke, the proliferated reactive astrocytes in the peri-infarct areas play a beneficial role in neuronal survival. As such, astrocytes have gradually become a target for neuroprotection in stroke. The present study assessed the hypothesis that Pinin (Pnn), originally identified as a nuclear and desmosome-associated protein and is now known to possess anti-apoptotic capacity, protects astrocytes from cell death after ischemic stroke and delineated the underlying mechanisms. METHODS: In in vivo experiments, adult male Sprague-Dawley rats (12-week old) were used to induce acute focal cerebral ischemia employing the middle cerebral artery occlusion (MCAO) method. In in vitro experiments, postnatal day 1 (P1) Sprague-Dawley rat pups were used to prepare cultures of primary astrocytes. Oxygen-glucose deprivation (OGD) and re-oxygenation (OGD/R) procedures were employed to mimic the hypoxic-ischemic condition of stroke in those astrocytes. RESULTS: We found in the peri-infarct area of the ipsilateral cortex and striatum in Sprague-Dawley rats after transient MCAO an increase in Pnn expression that correlated positively with the time-course of infarction as detected by T2-weighted imaging and triphenyltetrazolium chloride staining, augmented number of reactive astrocytes that double-labelled with Pnn as determined by immunofluorescence, and enhanced cytotoxic edema as revealed by diffusion weighted imaging; but mirrored the decreased cleaved caspase-3 as measured by western blot. In an OGD and OGD/R model using primary cultured astrocytes, treatment with Pnn siRNA doubled the chance of surviving astrocytes to manifest cell death as revealed by flow cytometry, and blunted activated ERK signaling, reduced Bcl-2 expression and augmented cleaved caspase 3 detected by western blot in the normoxia, OGD or OGD/R group. Gene-knockdown of Pnn also impeded the reversal from decline in cell viability, elevation in lactate dehydrogenase leakage and decrease in ATP production in the OGD/R group. CONCLUSION: We conclude that the endogenous Pnn participates in neuroprotection after acute ischemic stroke by preserving the viability of astrocytes that survived the ischemic challenge via maintenance of mitochondrial anti-apoptotic and bioenergetics functions.

The Impact of Maternal Fructose Exposure on Angiogenic Activity of Endothelial Progenitor Cells and Blood Flow Recovery After Critical Limb Ischemia in Rat Offspring.

Adult metabolic syndrome is considered to be elicited by the developmental programming which is regulated by the prenatal environment. The maternal excess intake of fructose, a wildly used food additive, is found to be associated with developmental programing-associated cardiovascular diseases. To investigate the effect of maternal fructose exposure (MFE) on endothelial function and repair, which participate in the initiation and progress of cardiovascular disease, we applied a rat model with maternal fructose excess intake during gestational and lactational stage and examined the number and function of endothelial progenitor cells (EPCs) in 3-month-old male offspring with induction of critical limb ischemia (CLI). Results showed that the circulating levels of c-Kit+/CD31+ and Sca-1+/KDR+ EPC were reduced by MFE. In vitro angiogenesis analysis indicated the angiogenic activity of bone marrow-derived EPC, including tube formation and cellular migration, was reduced by MFE. Western blots further indicated the phosphorylated levels of ERK1/2, p38-MAPK, and JNK in circulating peripheral blood mononuclear cells were up-regulated by MFE. Fourteen days after CLI, the reduced blood flow recovery, lowered capillary density, and increased fibrotic area in quadriceps were observed in offspring with MFE. Moreover, the aortic endothelium-mediated vasorelaxant response in offspring was impaired by MFE. In conclusion, maternal fructose intake during gestational and lactational stage modulates the number and angiogenic activity of EPCs and results in poor blood flow recovery after ischemic injury.

Prenatal Metformin Therapy Attenuates Hypertension of Developmental Origin in Male Adult Offspring Exposed to Maternal High-Fructose and Post-Weaning High-Fat Diets.

Widespread consumption of a Western diet, comprised of highly refined carbohydrates and fat, may play a role in the epidemic of hypertension. Hypertension can take origin from early life. Metformin is the preferred treatment for type 2 diabetes. We examined whether prenatal metformin therapy can prevent maternal high-fructose plus post-weaning high-fat diets-induced hypertension of developmental origins via regulation of nutrient sensing signals, uric acid, oxidative stress, and the nitric oxide (NO) pathway. Gestating Sprague-Dawley rats received regular chow (ND) or chow supplemented with 60% fructose diet (HFR) throughout pregnancy and lactation. Male offspring were onto either the ND or high-fat diet (HFA) from weaning to 12 weeks of age. A total of 40 male offspring were assigned to five groups (n = 8/group): ND/ND, HFR/ND, ND/HFA, HFR/HFA, and HFR/HFA+metformin. Metformin (500 mg/kg/day) was administered via gastric gavage for three weeks during the pregnancy period. Combined maternal HFR plus post-weaning HFA induced hypertension in male adult offspring, which prenatal metformin therapy prevented. The protective effects of prenatal metformin therapy on HFR/HFA-induced hypertension, including downregulation of the renin-angiotensin system, decrease in uric acid level, and reduction of oxidative stress. Our results highlighted that the programming effects of metformin administered prenatally might be different from those reported in adults, and that deserves further elucidation.

Maternal Melatonin Therapy Attenuated Maternal High-Fructose Combined with Post-Weaning High-Salt Diets-Induced Hypertension in Adult Male Rat Offspring.

Consumption of food high in fructose and salt is associated with the epidemic of hypertension. Hypertension can originate from early life. Melatonin, a pleiotropic hormone, regulates blood pressure. We examined whether maternal melatonin therapy can prevent maternal high-fructose combined with post-weaning high-salt diet-induced programmed hypertension in adult offspring. Pregnant Sprague-Dawley rats received either a normal diet (ND) or a 60% fructose diet (HF) during pregnancy and the lactation period. Male offspring were on either the ND or a high-salt diet (HS, 1% NaCl) from weaning to 12 weeks of age and were assigned to five groups (n = 8/group): ND/ND, HF/ND, ND/HS, HF/HS, and HF/HS+melatonin. Melatonin (0.01% in drinking water) was administered during pregnancy and lactation. We observed that maternal HF combined with post-weaning HS diets induced hypertension in male adult offspring, which was attenuated by maternal melatonin therapy. The beneficial effects of maternal melatonin therapy on HF/HS-induced hypertension related to regulating several nutrient-sensing signals, including Sirt1, Sirt4, Prkaa2, Prkab2, Pparg, and Ppargc1a. Additionally, melatonin increased protein levels of mammalian targets of rapamycin (mTOR), decreased plasma asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine levels, and increased the l-arginine-to-ADMA ratio. The reprogramming effects by which maternal melatonin therapy protects against hypertension of developmental origin awaits further elucidation.

The Regulations of Deubiquitinase USP15 and Its Pathophysiological Mechanisms in Diseases.

Deubiquitinases (DUBs) play a critical role in ubiquitin-directed signaling by catalytically removing the ubiquitin from substrate proteins. Ubiquitin-specific protease 15 (USP15), a member of the largest subfamily of cysteine protease DUBs, contains two conservative cysteine (Cys) and histidine (His) boxes. USP15 harbors two zinc-binding motifs that are essential for recognition of poly-ubiquitin chains. USP15 is grouped into the same category with USP4 and USP11 due to high degree of homology in an N-terminal region consisting of domains present in ubiquitin-specific proteases (DUSP) domain and ubiquitin-like (UBL) domain. USP15 cooperates with COP9 signalosome complex (CSN) to maintain the stability of cullin-ring ligase (CRL) adaptor proteins by removing the conjugated ubiquitin chains from RBX1 subunit of CRL. USP15 is also implicated in the stabilization of the human papillomavirus type 16 E6 oncoprotein, adenomatous polyposis coli, and IκBα. Recently, reports have suggested that USP15 acts as a key regulator of TGF-ß receptor-signaling pathways by deubiquitinating the TGF-ß receptor itself and its downstream transducers receptor-regulated SMADs (R-SMADs), including SMAD1, SMAD2, and SMAD3, thus activating the TGF-ß target genes. Although the importance of USP15 in pathologic processes remains ambiguous so far, in this review, we endeavor to summarize the literature regarding the relationship of the deubiquitinating action of USP15 with the proteins involved in the regulation of Parkinson's disease, virus infection, and cancer-related signaling networks.

Correction: Chon-Kit Chou, et al. The Regulations of Deubiquitinase USP15 and Its Pathophysiological Mechanisms in Diseases. Int. J. Mol. Sci. 2017, 18, 483.

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Time courses and value of circulating microparticles in patients with operable stage non-small cell lung cancer undergoing surgical intervention.

Microparticles (MPs) are substantially increased in patients with operable stage non-small cell lung cancer (NSCLC) prior to lung resection surgery. This study tested the hypothesis that there is a decrease in MPs after surgical intervention. Between March 2012 and January 2015, 33 patients who had operable stage NSCLC were consecutively and prospectively enrolled into the study. Additionally, 31 healthy subjects who were consecutively enrolled in the study period served as age- and gender-matched controls. Circulating MPs (EDAc-MPs, EDAp-MPs, PDAc-MPs, PDAp-MPs) were measured by flow cytometry once in control subjects and twice (i.e., prior to and three months later after surgical intervention) in NSCLC patients. Compared with control subjects, these four types of circulating MPs were significantly higher in NSCLC patients prior to operation (all P < 0.005), but did not differ among the controls and NSCLC patients at 3 months after surgery (all P > 0.2). Additionally, a receiver operating characteristic curve (ROC) showed that these four types of MPs were significantly valuable predictors for detecting early stage NSCLC (all P < 0.004). Circulating MPs which were remarkably increased in the operable stage of NSCLC prior to surgery were substantially decreased 3 months later after surgery. These findings show that circulating MPs might be an accessory biomarker for monitoring those of NSCLC after receiving lung resection surgery.

Developmental programming of the metabolic syndrome: Next-generation sequencing analysis of transcriptome expression in a rat model of maternal high fructose intake.

Excessive fructose intake is related to a high prevalence of metabolic syndrome, while little attention has been paid to the impact of maternal high-fructose (HF) intake on the development of metabolic syndrome and organ-specific transcriptome alterations in the offspring. We utilized RNA next-generation sequencing (NGS) technology to analyze the transcriptome expression in four organs (kidney, brain, heart, and urinary bladder) from 1-day, 3-week, and 3-month-old male offspring exposed to maternal HF diet. Maternal HF induced various phenotypes of metabolic syndrome in adult male offspring. We observed that maternal HF exposure induces long-term alterations of gene expression in the brain, heart, kidney, and urinary bladder in adult offspring. Different organs do not respond similarly to maternal HF intake. We found that changes in expression of Errfi1 and Ctgf were shared by four organs at 1 day of age. Also, a number of genes regulating fructose metabolism, glycolysis/gluconeogenesis, fatty acid metabolism, and insulin signalling appear to be regulated by maternal HF intake in different organs at 1 day of age. Our NGS results are of significance to the development of maternal interventions in the prevention of maternal HF-induced organ-specific programming, in order to reduce the global burden of metabolic syndrome.

Intracoronary Transfusion of Circulation-Derived CD34+ Cells Improves Left Ventricular Function in Patients With End-Stage Diffuse Coronary Artery Disease Unsuitable for Coronary Intervention.

OBJECTIVE: This study tested the hypothesis that intra-coronary transfusion of circulation-derived autologous CD34+ cells can improve ischemia-related left ventricular dysfunction in patients with severe diffuse coronary artery disease refractory to medication and unsuitable for coronary intervention. DESIGN: A prospective, randomized, double-blinded phase I clinical trial. SETTING: Tertiary care center. PATIENTS: Thirty-eight patients with severe diffuse coronary artery disease were randomized into group 1 and group 2 receiving CD34+ cell infusion with dosages of 1.0 x 107 and 3.0 x 107 cells/vessel, respectively, after subcutaneous G-CSF injection (5 µg/kg twice a day for 4 d). INTERVENTIONS: Cardiac catheterization and intra-coronary administration of CD34+ cells. MEASUREMENTS AND MAIN RESULTS: This clinical trial was to test effectiveness and safety of these two different dosages of CD34+ cells in the setting of severe diffuse coronary artery disease. Blood samples were collected for endothelial progenitor cell culture before and after granulocyte colony-stimulating factor injection for matrigel-assay and comparison of levels of soluble angiogenesis factors (vascular endothelial growth factor, epithelial growth factor, hepatocyte growth factor, angiopoietin-1, and transforming growth factor-ß). Procedural safety was 100% with all patients uneventfully discharged. The numbers of endothelial progenitor cells in blood samples from coronary sinus after transfusion were higher than those in circulation, and the circulatory level was higher after granulocyte colony-stimulating factor treatment (all p < 0.001). Cardiac MRI and three-dimensional echocardiography at 6 month and angiographic follow-up at 9 month showed improvement in left ventricular ejection fraction (p < 0.001) and consistent increase in neovascularization (p < 0.001), respectively, in both groups. Despite good correlation in angiogenesis between 9-month angiography and matrigel-assay (p < 0.001), no significant correlation was noted in of soluble angiogenesis factor levels. Angina and heart failure were improved in both groups at 12-month follow-up (all p < 0.001). The survival rate at 18.5-month follow-up was 94.7% (n = 36). CONCLUSIONS: CD34+ cell therapy was safe and efficacious in improving heart function for patients with severe diffuse coronary artery disease unsuitable for coronary intervention and with poor response to pharmacotherapy.

Administered circulating microparticles derived from lung cancer patients markedly improved angiogenesis, blood flow and ischemic recovery in rat critical limb ischemia.

BACKGROUND: We hypothesized that lung cancer patient's circulating microparticles (Lc-MPs) could promote angiogenesis, blood flow in ischemic zone and ischemic recovery in rat critical limb ischemia (CLI). METHODS: To investigate the impact of MP therapy on reversing the setting of CLI, adult-male Sprague-Dawley rats (n=50) equally randomized into sham control (SC) (group 1), SC-Lc-MPs (1.0 x 10(7) particles) (group 2), CLI (group 3), CLI-Hs-MPs (MPs from healthy-subject) (group 4), and CLI-Lc-MPs (group 5) were sacrificed by post-CLI day-14. RESULTS: In vitro study showed that Lc-MPs enhanced VEGFR2 expression, angiogenesis, nitric-oxide production, and endothelial cell proliferation (all p<0.005). By days 7 and 14, Laser Doppler showed significantly higher ischemic/normal blood-flow ratio in groups 1 and 2 compared with group 3, and was significantly higher in group 4 and further elevated in group 5 (p<0.0001). Numbers of small vessels and endothelial markers (CD31(+) and vWF(+) cells) and protein expressions (eNOS, CD31) exhibited a pattern identical to Lasre Doppler among the five groups (all p<0.001). Pro-angiogenic factors (VEGF, CXCR4, SDF-1α, HGF) at cellular and protein levels showed a significant step-wise increase from groups 1 and 2 to groups 3, 4, and 5 (all p<0.001). Protein expressions of fibrotic (Smad3, TGF-ß) and apoptotic (mitochondrial Bax, cleaved caspase 3, and PARP) biomarkers displayed an opposite pattern compared to that of Laser Doppler, whereas the protein expressions of anti-fibrotic (Smad1/5, BMP-2) and anti-apoptotic (Bcl-2) biomarkers showed an identical pattern compared with that of Laser Doppler among groups 1 to 3, and 5 (all p<0.001). CONCLUSION: Administration of Lc-MPs augmented angiogenesis and restored blood flow in a rat of CLI.

Systemic combined melatonin-mitochondria treatment improves acute respiratory distress syndrome in the rat.

Despite high in-hospital mortality associated with acute respiratory distress syndrome (ARDS), there is no effective therapeutic strategy. We tested the hypothesis that combined melatonin-mitochondria treatment ameliorates 100% oxygen-induced ARDS in rats. Adult male Sprague-Dawley rats (n = 40) were equally categorized into normal controls, ARDS, ARDS-melatonin, ARDS with intravenous liver-derived mitochondria (1500 µg per rat 6 hr after ARDS induction), and ARDS receiving combined melatonin-mitochondria. The results showed that 22 hr after ARDS induction, oxygen saturation (saO2 ) was lowest in the ARDS group and highest in normal controls, significantly lower in ARDS-melatonin and ARDS-mitochondria than in combined melatonin-mitochondria group, and significantly lower in ARDS-mitochondria than in ARDS-melatonin group. Conversely, right ventricular systolic blood pressure and lung weight showed an opposite pattern compared with saO2 among all groups (all P < 0.001). Histological integrity of alveolar sacs showed a pattern identical to saO2 , whereas lung crowding score exhibited an opposite pattern (all P < 0.001). Albumin level and inflammatory cells (MPO+, CD40+, CD11b/c+) from bronchoalveolar lavage fluid showed a pattern opposite to saO2 (all P < 0.001). Protein expression of indices of inflammation (MMP-9, TNF-α, NF-κB), oxidative stress (oxidized protein, NO-1, NOX-2, NOX-4), apoptosis (mitochondrial Bax, cleaved caspase-3, and PARP), fibrosis (Smad3, TGF-ß), mitochondrial damage (cytochrome C), and DNA damage (γ-H2AX+) exhibited an opposite pattern compared to saO2 in all groups, whereas protein (HO-1, NQO-1, GR, GPx) and cellular (HO-1+) expressions of antioxidants exhibited a progressively increased pattern from normal controls to ARDS combined melatonin-mitochondria group (all P < 0.001). In conclusion, combined melatonin-mitochondrial was superior to either treatment alone in attenuating ARDS in this rat model.

Sitagliptin protects rat kidneys from acute ischemia-reperfusion injury via upregulation of GLP-1 and GLP-1 receptors.

AIM: Sitagliptin, an oral glucose-lowering agent, has been found to produce cardiovascular protection possibly via anti-inflammatory and anti-atherosclerotic activities of glucagon-like peptide-1 receptor (GLP-1). The aim of this study was to investigate whether sitagliptin protected the kidney function from acute ischemia-reperfusion (IR) injury in rats. METHODS: Adult male SD rats were categorized into 4 groups: sham control, IR injury, IR+sitagliptin (300 mg/kg) and IR+sitagliptin (600 mg/kg). Acute renal IR injury of both kidneys was induced by clamping the renal pedicles for 1 h. The drug was orally administered at 1, 24 and 48 h after acute IR. Blood samples and 24-h urine were collected before and at 72 h after acute IR. Then the rats were sacrificed, and the kidneys were harvested for biochemical and immunohistochemical studies. RESULTS: Acute IR procedure markedly increased serum levels of creatinine and BUN and the ratio of urine protein to creatinine. The kidney injury score, inflammatory biomarkers (MMP-9, TNF-α and NF-κB) levels and CD68+ cells in IR kidneys were considerably increased. The expression of oxidized protein, reactive oxygen species (NOX-1, NOX-2) and apoptosis proteins (Bax, caspase-3, PARP) in IR kidneys was also significantly upregulated. All these pathological changes were suppressed by sitagliptin in a dose-dependent manner. Furthermore, the serum GLP-1 level, and the expression of GLP-1 receptor, anti-oxidant biomarkers (HO-1 and NQO-1 cells, as well as SOD-1, NQO-1 and HO-1 proteins), and angiogenesis markers (SDF-1α+ and CXCR4+ cells) in IR kidneys were significantly increased, and further upregulated by sitagliptin. CONCLUSION: Sitagliptin dose-dependently protects rat kidneys from acute IR injury via upregulation of serum GLP-1 and GLP-1 receptor expression in kidneys.

Loss of Pnn expression results in mouse early embryonic lethality and cellular apoptosis through SRSF1-mediated alternative expression of Bcl-xS and ICAD.

Pinin (Pnn), a serine/arginine-rich (SR)-related protein, has been shown to play multiple roles within eukaryotic cells including cell-cell adhesion, cell migration, regulation of gene transcription, mRNA export and alternative splicing. In this study, an attempt to generate mice homozygously deficient in Pnn failed because of early embryonic lethality. To evaluate the effects of loss of Pnn expression on cell survival, RNA interference experiments were performed in MCF-7 cells. Depletion of Pnn resulted in cellular apoptosis and nuclear condensation. In addition, nuclear speckles were disrupted, and expression levels of SR proteins were diminished. RT-PCR analysis showed that alternative splicing patterns of SRSF1 as well as of apoptosis-related genes Bcl-x and ICAD were altered, and expression levels of Bim isoforms were modulated in Pnn-depleted cells. Cellular apoptosis induced by Pnn depletion was rescued by overexpression of SRSF1, which also restored generation of Bcl-xL and functionless ICAD. Pnn expression is, therefore, essential for survival of mouse embryos and the breast carcinoma cell line MCF-7. Moreover, Pnn depletion, modulated by SRSF1, determines cellular apoptosis through activation of the expression of pro-apoptotic Bcl-xS transcripts.

Inhibition of dipeptidyl peptidase-IV enzyme activity protects against myocardial ischemia-reperfusion injury in rats.

BACKGROUND: We investigated whether attenuating dipeptidyl peptidase-IV (DPP4) enzyme activity protected rat heart from ischemia-reperfusion (IR) injury (40-min left anterior descending coronary artery ligation followed by 72 h reperfusion). METHODS AND RESULTS: Adult male Fischer 344 rats (n = 24) were equally divided into sham-control (WT-SC), WT-IR, and WT-IR-Sita (oral sitagliptin 400 mg/kg/day for 3 days) groups, whereas adult male DPP4-deficiency (DPP4(D)) rats (n = 16) were equally divided into DPP4(D)-SC and DPP4(D)-IR groups. Animals were sacrificed at 72 h after reperfusion with collection of heart specimens. Infarct area (H&E), collagen deposition (Sirius-red stain), fibrotic area (Masson's trichrome), and fluorescent-ROS intensity (H2DCFDA-labeling myocardium) of left ventricle were significantly higher in WT-IR than those in other groups, significantly higher in WT-IR-Sita and DPP4(D)-IR groups than in WT-SC and DPP4(D)-SC groups (all p < 0.001), but there was no difference between the latter two groups. Protein expressions of oxidative stress (oxidized protein), reactive oxygen species (NOX-1, NOX-2), inflammation (TNF-α, NF-κB, MMP-9, VCAM-1), apoptosis (mitochondrial Bax, cleaved caspase-3 and PARP), myocardial damage markers (cytosolic cytochrome-C, γ-H2AX), and number of inflammatory cells (CD14+, CD68+, CD40+ cells) showed a pattern identical to that of histological changes among all groups (all p < 0.005), whereas markers of anti-apoptosis (Bcl-2) and mitochondrial integrity (mitochondrial cytochrome-C) as well as left ventricular ejection fraction showed an opposite pattern (all p < 0.001). Protein expressions of anti-oxidants (HO-1, NQO-1), angiogenesis factors (SDF-1α, CXCR4), and glycogen-like-peptide-1-receptor were significantly higher inWT-IR-Sita and DPP4(D)-IR than those in other groups (all p <0.001). CONCLUSION: Abrogation of DPP4 activity protects against myocardial IR injury and preserved heart function.

Levels and values of lipoprotein-associated phospholipase A2, galectin-3, RhoA/ROCK, and endothelial progenitor cells in critical limb ischemia: pharmaco-therapeutic role of cilostazol and clopidogrel combination therapy.

OBJECTIVE: We tested the hypothesis that clopidogrel and cilostazol combination therapy could effectively attenuate systemic inflammatory reaction, facilitate proliferation of circulating endothelial progenitor cell (EPC), and improve the clinical outcomes of critical limb ischemia (CLI) in patients unsuitable for surgical revascularization or percutaneous transluminal angioplasty (PTA). METHODS: A total 55 patients (mean age, 72 years; 56% female) were consecutively enrolled. Clopidogrel and cilostazol combination therapy was administered throughout the study period. RESULTS: As compared with the baseline, circulating endothelial progenitor cell level (as shown by flow cytometry) was significantly increased (p<0.003), whereas the CLI-related ulcers and painfulness were significantly improved (all p<0.01) by day 90 after treatment. On the other hand, after clopidogrel and cilostazol combination therapy, galectin-3 level, lipoprotein-associated phospholipase A2 gene expression, and RhoA/ROCK-related protein expression in peripheral blood mononuclear cells were significantly suppressed (all p<0.01). Eventually, by day 90, 5 patients (9.1%) died of other etiologies, 3 (5.5%) withdrew from the study, 6 (10.9%) required amputation, and the remaining 41 had satisfactory clinical improvement with complete wound healing in 9 (16.4%) patients. CONCLUSION: The results of the present study highlight that clopidogrel and cilostazol combination therapy may be considered to be an alternative method for treating patients with CLI unsuitable for surgical revascularization or PTA.