Cardioprotective role of a magnolol and honokiol complex in the prevention of doxorubicin-mediated cardiotoxicity in adult rats.

Doxorubicin (DOXO) induces marked cardiotoxicity, though increased oxidative stress while there are some documents related with cardioprotective effects of some antioxidants against organ-toxicity during cancer treatment. Although magnolia bark has some antioxidant-like effects, its action in DOXO-induced heart dysfunction has not be shown clearly. Therefore, here, we aimed to investigate the cardioprotective action of a magnolia bark extract with active component magnolol and honokiol complex (MAHOC; 100 mg/kg) in DOXO-treated rat hearts. One group of adult male Wistar rats was injected with DOXO (DOXO-group; a cumulative dose of 15 mg/kg in 2-week) or saline (CON-group). One group of DOXO-treated rats was administered with MAHOC before DOXO (Pre-MAHOC group; 2-week) while another group was administered with MAHOC following the 2-week DOXO (Post-MAHOC group). MAHOC administration, before or after DOXO, provided full survival of animals during 12-14 weeks, and significant recoveries in the systemic parameters of animals such as plasma levels of manganese and zinc, total oxidant and antioxidant statuses, and also systolic and diastolic blood pressures. This treatment also significantly improved heart function including recoveries in end-diastolic volume, left ventricular end-systolic volume, heart rate, cardiac output, and prolonged P-wave duration. Furthermore, the MAHOC administrations improved the structure of left ventricles such as recoveries in loss of myofibrils, degenerative nuclear changes, fragmentation of cardiomyocytes, and interstitial edema. Biochemical analysis in the heart tissues provided the important cardioprotective effect of MAHOC on the redox regulation of the heart, such as improvements in activities of glutathione peroxidase and glutathione reductase, and oxygen radical-absorbing capacity of the heart together with recoveries in other systemic parameters of animals, while all of these benefits were observed in the Pre-MAHOC treatment group, more prominently. Overall, one can point out the beneficial antioxidant effects of MAHOC in chronic heart diseases as a supporting and complementing agent to the conventional therapies.

An Overexpression of SLC30A6 Gene Contributes to Cardiomyocyte Dysfunction via Affecting Mitochondria and Inducing Activations in K-Acetylation and Epigenetic Proteins.

Intracellular free Zn2+ ([Zn2+]i) is less than 1-nM in cardiomyocytes and its regulation is performed with Zn2+-transporters. However, the roles of Zn2+-transporters in cardiomyocytes are not defined exactly yet. Here, we aimed to examine the role of an overexpression and subcellular localization of a ZnT6 in insulin-resistance mimic H9c2 cardiomyoblasts (IR-cells; 50-µM palmitic acid for 24-h incubation). We used both IR-cells and ZnT6-overexpressed (ZnT6OE) cells in comparison to those of H9c2 cells (CON-cells). The IR-cells have higher ZnT6-protein levels than CON-cells while this level was similar to those of ZnT6OE-cells. The [Zn2+]i in IR-cells was increased significantly and mitochondrial localization of ZnT6 was demonstrated in these cells by using confocal microscopy visualization. Furthermore, electron microscopy analysis demonstrated abnormal morphological appearance in both IR-cells and ZnT6OE-cells characterized by irregular mitochondrion cristae and condensed and dilated cisterna in the sarcoplasmic reticulum. Mitochondria were similarly depolarized in both IR-cells and ZnT6OE-cells. The protein expression level of a mitofusin protein MFN2 in the IR-cells was decreased, significantly, whereas, it was found significantly upregulated in both ZnT6-OE-cells and IR-incubated ZnT6OE-cells, which demonstrates the role of ZnT6-overexpression but not IR. Additionally, the total protein level of a mitochondrial fission protein, dynamin-related protein 1, DRP1 was found to be increased over 1.5-fold in IR-cells while this increase was found to be higher in the ZnT6OE-cells than those of IR-cells, demonstrating an additional effect on IR-increase. ZnT6-overexpression induced also significant increases in K-acetylation, trimethylation of histone H3 lysine27, and mono-methylation of histone H3 lysine36, in a similar manner to those of IR-cells. Overall, our data point out an important contribution of ZnT6-overexpression to IR-induced cellular changes, such as alteration in mitochondria function and activation of epigenetic modifications.

An increase in intercellular crosstalk and electrotonic coupling between cardiomyocytes and nonmyocytes reshapes the electrical conduction in the metabolic heart characterized by short QT intervals in ECGs.

Cardiac conduction abnormalities are disorders in metabolic syndrome (MetS), however, their mechanisms are unknown. Although ventricular arrhythmia reflects the changes in QT-interval of electrocardiograms associated with the changes in cardiomyocyte action potential durations (APDs), recent studies emphasize role of intercellular crosstalk between cardiomyocytes and nonmyocytes via passive (electrotonic)-conduction. Therefore, considering the possible increase in intercellular interactions of nonmyocytes with cardiomyocytes, we hypothesized an early-cardiac-remodeling characterized by short QT-interval via contributions and modulations of changes by nonmyocytes to the ventricular APs in an early-stage MetS hearts. Following the feeding of 8-week-old rats with a high-sucrose diet (32%; MetS rats) and validation of insulin resistance, there was a significant increase in heart rate and changes in the electrical characteristics of the hearts, especially a shortening in action potential (AP) duration of the papillary muscles. The patch-clamp analysis of ventricular cardiomyocytes showed an increase in the Na+ -channel currents while there were decreases in  l-type Ca2+ -channel (LTCC) currents with unchanged K+ -channel currents. There was an increase in the phosphorylated form of connexin 43 (pCx43), mostly with lateral localization on sarcolemma, while its unphosphorylated form (Cx43) exhibited a high degree of localization within intercalated discs. A high-level positively-stained α-SMA and CD68 cells were prominently localized and distributed in interfibrillar spaces of the heart, implying the possible contributions of myofibroblasts and macrophages to both shortened APDs and abnormal electrical conduction in MetS hearts. Our data propose a previously unrecognized pathway for SQT induction in the heart. This pathway includes not only the contribution of short ventricular-APDs via ionic mechanisms but also increasing contributions of the electrotonic-cardiomyocyte depolarization, spontaneous electrical activity-associated fast heterogeneous impulse conduction in the heart via increased interactions and relocations between cardiomyocytes and nonmyocytes, which may be an explanation for the development of an SQT in early-cardiac-remodeling.

Morphological and Functional Analysis of Cardiac Ameliorations in Elderly Rats Supplemented with a Magnolol Extract Complex / Análisis Morfológico y Funcional de las Mejoras Cardíacas en Ratas Ancianas Suplementadas con un Complejo de Extracto de Magnolol

SUMMARY: Magnolia bark extract supplementation has an anti-oxidative role in mammalians. However, its role in physiological aged-associated heart insufficiency is not known yet. Therefore, we investigated the effects of a magnolia bark complex, including magnolol and honokiol components (MAHOC), in elderly rat hearts (24-month-old aged group). One group of aged rats was supplemented with MAHOC (400 mg/kg/d, for 12 weeks) besides the standard rat diet while the second group of elderly rats and adult rats (to 6-month- old adult-group) were only fed with the standard rat diet. The morphological analysis using light microscopy has shown marked myofibrillar losses, densely localized fibroblasts, vacuolizations, infiltrated cell accumulations, and collagen fibers in the myocardium of the elderly rats compared to the adults. We also detected a markedly increased amount of degenerated cardiomyocytes including the euchromatic nucleus. The MAHOC supplementation of the elderly rats provided marked ameliorations in these abnormal morphological changes in the heart tissue. Furthermore, electrophysiological analysis of electrocardiograms (ECGs) in the supplemented group showed significant attenuations in the prolonged durations of P-waves, QRS-complexes, QT-intervals, and low heart rates compared to the unsupplemented elderly group. The biochemical analysis also showed significant attenuations in the activity of arylesterase and total antioxidant status in the myocardium of the supplemented group. We further determined significant attenuations in the activity of a mitochondrial enzyme succinate dehydrogenase, known as a source of reactive oxygen species (ROS), and the decreased level of ATP/ADP in the heart homogenates of the supplemented group. Moreover, under in vitro conditions by using an aging-mimicked cardiac cell line induced by D-galactose, we demonstrated that MAHOC treatment could provide prevention of depolarization in mitochondria membrane potential and high-level ROS production. Overall, our data presented significant myocardial ameliorations in physiological aging-associated morphological alterations parallel to the function and biochemical attenuations with MAHOC supplementation, at most, through recoveries in mitochondria.

La suplementación con extracto de corteza de magnolia tiene un papel antioxidante en los mamíferos, sin embargo, su rol en la insuficiencia cardíaca asociada al envejecimiento fisiológico aún no se conoce. Por lo anterior, investigamos los efectos de un complejo de corteza de magnolia, incluidos los componentes magnolol y honokiol (MAHOC), en corazones de ratas seniles (grupo de edad de 24 meses). La alimentación de grupo de ratas seniles se complementó con MAHOC (400 mg/kg/d, durante 12 semanas) además de la dieta estándar, mientras que el segundo grupo de ratas seniles y ratas adultas (hasta el grupo de adultos de 6 meses) solo recibió la dieta estándar para ratas. El análisis morfológico mediante microscopía óptica ha mostrado marcadas pérdidas miofibrilares, fibroblastos densamente localizados, vacuolizaciones, acumulaciones de células infiltradas y fibras de colágeno en el miocardio de las ratas seniles en comparación con las adultas. También detectamos una cantidad notablemente mayor de cardiomiocitos degradados, incluido el núcleo eucromático. La suplementación con MAHOC de las ratas seniles proporcionó mejoras marcadas en estos cambios morfológicos anormales en el tejido cardiaco. Por otra parte, el análisis de los electrocardiogramas (ECG) en el grupo suplementado mostró atenuaciones significativas en las duraciones prolongadas de las ondas P, los complejos QRS, los intervalos QT y las frecuencias cardíacas bajas, en comparación con el grupo de ratas seniles sin suplementación alimenticia. El análisis bioquímico también mostró atenuaciones significativas en la actividad de la arilesterasa y el estado antioxidante total en el miocardio del grupo suplementado. Determinamos además atenuaciones significativas en la actividad de la enzima mitocondrial succinato deshidrogenasa, conocida como fuente de especies reactivas de oxígeno (ROS), y la disminución del nivel de ATP/ADP en los homogeneizados de corazón del grupo suplementado. Además, en condiciones in vitro mediante el uso de una línea de células cardíacas, imitando el envejecimiento inducido por D- galactosa, demostramos que el tratamiento con MAHOC podría prevenir la despolarización en el potencial de membrana de las mitocondrias y la producción de ROS de alto nivel. En general, nuestros datos presentaron mejoras miocárdicas significativas en alteraciones morfológicas asociadas con el envejecimiento fisiológico paralelas a la función y atenuaciones bioquímicas con la suplementación con MAHOC, como máximo, a través de recuperaciones en las mitocondrias.

The effects of cisplatin and jaceosidin on SH-SY5Y neuroblastoma cells: an electron microscopic, molecular and biochemical study.

In this study, our aim was to show both the single and combined effects of cisplatin and jaceosidin in SHSY-5Y neuroblastoma cells. For this purpose, we used MTT cellular viability assay, Enzyme-Linked Immunosorbent Assay (ELISA), Transmission Electron Microscopy (TEM), Immunofluorescence Staining Assay (IFA) and Western blotting (WB) assay. According to MTT findings, IC50 dose was detected as 50 µM cisplatin and 160 µM jaceosidin co-application. Therefore, experimental groups were finally selected as control, cisplatin, 160 µM jaceosidin and Cisplatin +160 µM jaceosidin. Cell viability was decreased in all groups, and the IFA findings confirmed the viability analysis. WB data indicated that matrix metalloproteinase 2 and 9 levels, as indicators of metastasis, decreased. While LPO and CAT levels increased in all treatment groups, it was observed that the activity of SOD decreased. When TEM micrographs were investigated, cellular damages were determined. In the light of these results, it can be said that cisplatin and jaceosidin have a potential to increase the effects of each other synergistically.

Nasal mucociliary clearance after extremely low frequency by scintigraphic and histopathologic evaluation.

OBJECTIVE: To investigate the effect of exposure to extremely low-frequency magnetic fields (ELF-MFs) on nasal mucociliary clearance (MCC) by rhinosintigrapic and histopathological evaluation. MATERIALS AND METHODS: The rats were separated into three groups according to ELF-MFs intensity and control group. The exposure groups were standardized for the ELF-MFs of 1, 1.5, and 2 mT emitted by 3 Helmholtz coils for 4 h/day for 30 days. Rhinoscintigraphy was performed to measure nasal MCC. The nasal tissues were examined for edema, inflammation, hyperemia, necrosis, ciliary loss, goblet cell density, and fibroblast proliferation. The data were evaluated statistically (p < 0.05). RESULTS: Nasal mucociliary clearance rates (NMCR) were calculated as 33.13 ± 5.91% in control, 27.78 ± 4.7% in 1 mT, 22.67 ± 5.43% in 1.5 mT, and 18.11 ± 6.33% in 2 mT. NMCR were decreased with increasing ELF-MFs, in 1.5 and 2 mT groups (p < 0.05) compared to control. Nasal mucociliary transport rate (NMTR) values were found to be 2.17 ± 0.33 mm/min in control, 1.82 ± 0.32 mm/min in 1 mT, 1.46 ± 0.34 mm/min in 1.5 mT and 1.24 ± 0.29 mm/min in 2 mT. NMTR was decreased in the groups exposed to 1.5 and 2 mT (p < 0.05) compared to control. The edema, hyperemia, inflammation, ciliary loss, and goblet cell density were statistically significant differences between control and groups exposed to 1.5 and 2 mT (p < 0.05). CONCLUSION: Our rat model has shown nasal mucosa damage and decreased NMCR and NMTR by rhinoscintigraphy as ELF-MFs intensity increases. It may be detrimental to nasal mucosa mucociliary function depending on the ELF-MFs intensity. LEVEL OF EVIDENCE: N/A Laryngoscope, 133:2081-2089, 2023.

Alterations in hippocampal neurogenesis and hippocampal insulin signaling pathway in rat with metabolic syndrome.

Objectives: We aimed to examine the level of hippocampal neurogenesis, and assess learning and anxiety and the level of some proteins involving insulin signaling pathways in rats with Metabolic Syndrome (MetS); and to reveal the relationship among them. Materials and Methods: Totally, 30 Wistar-albino rats were used. The rats were divided into three groups: Control, MetS, and MetS+Ins. Immunohistochemical staining was performed to evaluate the levels of neurogenesis markers; Doublecortin (DCX), Neuronal-Differentiation-1 (NeuroD1), Ki67, and Neuronal nuclear protein (NeuN). Then, cleaved caspase-3 and TUNEL labeling were performed to detect the level of apoptosis. Additionally, behavior tests were performed to evaluate the learning-memory levels and anxiety-like behaviors. Insulin, Insulin Receptor (IR), Insulin Receptor Substrate (IRS2), glucose transporter (GLUT)-3, and GLUT4 protein expression levels were analyzed to evaluate the possible changes in the insulin signaling pathway. Results: An increase in anxiety with memory deficiency was observed in MetS. In the hippocampus of MetS, an increase was detected in the level of apoptosis, whereas a decrease was detected in the expression level of the neurogenesis marker. Insulin secretion and IR levels decreased in hippocampal neurons. We observed that GLUT3 and GLUT4 levels increased because of the non-activated insulin signaling pathway. Conclusion: We think that the insulin signaling pathway may have an effect on the decreased neurogenesis in the MetS group. So, the evaluation of the Mitogen-activated protein kinase (MAPK) pathway and the investigation of the effect of endoplasmic reticulum stress on this pathway will be among the targets of our future studies.

Intracellular Redistribution of Left Ventricular Connexin 43 Contributes to the Remodeling of Electrical Properties of the Heart in Insulin-resistant Elderly Rats.

The correlation between long-QT and connexin 43 (Cx43) status and localization in elderly rats was determined to demonstrate a correlation between insulin resistance (I-R), ischemia-reperfusion, aging, and heart dysfunction. Male Wistar rats are grouped as 24-month-old rats (Aged-group), those with metabolic syndrome (8 months old; MetS-group), or controls (8 months old; Con-group). Both experimental groups have long-QT and low heart rate. Immunohistochemical imaging and quantification showed marked decreases in Cx43 staining of intercalated disc with less localizations in the Aged-group and MetS-group. The lateralization of Cx43 on longitudinal cell membrane was significantly high in the MetS-group than in the Con-group with no significant change in the Aged-group. Its significant cytoplasmic internalization was higher in the Aged-group than in the MetS-group. There were marked decreases in phospho-Cx43 (pCx43) staining of intercalated disc with less localizations in both groups than in the Con-group. Furthermore, lateralization of pCx43 was significantly low in the Aged-group and MetS-group, whereas there were no significant changes in the cytoplasmic internalization of both groups compared with the Con-group. Furthermore, the ratio of pCx43 to Cx43 was significantly small in both groups. We determined increases in RhoA and endothelin-1 in both groups, further supporting decreases in pCx43. Our data indicate the important role of I-R on long-QT in aging heart through alterations in both Cx43 protein level and localizations, leading to an abnormal spreading of ventricular repolarization in I-R heart.

Influence of galantamine on peripheral nerve degeneration after experimental compression injury of the rat sciatic nerve.

BACKGROUND: Galantamine is well-known for its neuroprotective effects and is currently used in the treatment of individuals with Alzheimer's disease. In this study, we induced experimental sciatic nerve injury (SCI) in rats to test the beneficial effects of galantamine. METHODS: Thirty male Wistar albino rats were divided into three groups, as follows: sham, SCI + saline, and SCI + galantamine. After the administration of an intraperitoneal ketamine and xylazine mixture, which was used for anesthesia, SCI was induced by sur-gical clip compression at the midthigh region of the rats. After surgery, a single daily intraperitoneal dose of galantamine was adminis-tered for 7 days, and nerve tissue sections were obtained 1 week after injury. Histopathology studies were performed to assess neural thickness and apoptotic cell counts, and light microscopic morphological examination was used to determine a potential beneficial effect of galantamine on peripheral nerve degeneration. RESULTS: We observed a markedly increased microvasculature, increased nerve fiber thickness, and a statistically significant increase in apoptotic cell counts distal to the level of injury in the saline group compared with the sham group. However, the increases in nerve fiber thickness and apoptotic cell counts were less in the galantamine group compared with the saline group. CONCLUSION: In our experimental model, pharmacological intervention with galantamine demonstrated a protective effect on degeneration after peripheral nerve injury.

Bimodal Effects of P2Y12 Antagonism on Matrix Metalloproteinase-Associated Contractile Dysfunction in Insulin-Resistant Mammalian Heart.

The matrix metalloproteinases (MMPs) contribute to matrix remodeling in diabetes via tissue degradation; however, their contributions can be different depending on the pathology. For instance, MMPs are elevated in acute stress hyperglycemia, whereas they can be degraded in chronic hyperglycemia. Since studies emphasize the possible cardioprotective effect of ticagrelor (Tica) beyond its antiplatelet action, we aimed to examine whether Tica treatment can reverse the depressed heart function of metabolic syndrome (MetS) rats via affecting the expression levels of MMPs. Tica treatment of high-carbohydrate-induced MetS rats could not affect significantly the depressed contractile activity of Langendorff-perfused heart preparations. On the other hand, the Tica treatment provided a significant recovery in the reduced relaxation activity of the aortic preparations from the same animals. Histological examination of the hearts demonstrated marked damages in Mets rats, such as increases in the number of foamy cells and accumulation of collagen fiber and increases in the elastic lamellar irregularity of tunica media, while Tica treatment provided a slight improvement in the structure of left ventricle tissue. We also could not obtain a significant reverse in the high cytosolic labile Zn2+ ([Zn2+]i) with the treatment of cardiomyocytes with Tica. Furthermore, Tica treatment of MetS rats could not significantly reverse the degraded protein levels of MMP-2 and MMP-9 in the heart, as well. Overall, we demonstrated that Tica treatment of MetS rats has no significant benefits on the depressed heart function, although provide a significant beneficial impact on vascular relaxation. This action of Tica may be through its lack of action on both MMP degradation and high [Zn2+]i, which can further precipitate in cleavage of extracellular matrix in the heart.

Effects of aerobic exercise on lipopolysaccharide-induced experimental acute lung injury in the animal model of type 1 diabetes mellitus.

NEW FINDINGS: What is the central question of this study? We evaluated the effects of diabetes and exercise on lipopolysaccharide-induced acute lung injury. By providing a comprehensive analysis of redox status, blood gases and histological parameters, we aimed to contribute to the ongoing debate in the literature. What are the main findings and its importance? We demonstrated the preventive effect of exercise, but diabetes did not alter the severity of acute lung injury. ABSTRACT: Acute lung injury (ALI) is a life-threatening respiratory condition. Diabetes (DM) is a metabolic disease characterized by hyperglycaemia. There is an ongoing debate concerning whether there is a protective effect of diabetes in ALI. Exercise is a special type of physical activity that has numerous beneficial effects. The aim of our study was to investigate the effects of diabetes and exercise on the prognosis of ALI. Male Wistar albino rats were divided into two groups (sedentary and exercise). Both groups were divided into four subgroups: Control, ALI, DM, DM+ALI (n = 6 each). Diabetes was induced by injection of streptozotocin (50 mg/kg i.p.). The maximal exercise capacity was determined with the incremental load test. Animals were exercised on a treadmill for 45 min at 70% of maximal exercise capacity, 5 days a week for 12 weeks. Acute lung injury was induced by intratracheal injection of lipopolysaccharide (100 µg/100 g body weight) 24 h before the end of the experiment. We performed arterial blood gas analysis. Redox status was measured in both plasma and lung tissue. Malondialdehyde and 8-hydroxy-2'-deoxyguanosine levels were measured in lung tissue. Lung tissue was evaluated histologically. Acute lung injury caused significant damage in the lung tissue, which was verified histologically, with an increase in oxidative stress parameters. Exercise prevented the lung damage induced by ALI and reduced oxidative stress in the lung tissue. Diabetes did not alter the magnitude of damage done by ALI. Exercise showed a protective effect against DM and ALI in rats. The effect of DM was insignificant for the prognosis of ALI.

Histologic and Immunohistochemical Assessment of the Effect of Various Biomaterials on New Bone Formation in the Maxillary Sinus Floor Augmentation Procedure.

PURPOSE: To assess the effect of different kinds of biomaterials placed with maxillary sinus floor augmentation (MSFA) on bone regeneration. MATERIALS AND METHODS: Thirty-six New Zealand rabbits were used in the study. A standardized method of surgical approach was used for MSFA under anesthesia in all groups. The procedure was performed for each animal. Six separate groups with 12 cases were created. In group 1, no graft was used in MSFA. Advanced platelet-rich fibrin (A-PRF), absorbable collagen cone (ACC), venous blood, the combination of ACC and platelet-rich plasma (PRP), and the combination of ACC and enamel matrix derivative (EMD) were used in groups 2, 3, 4, 5, and 6, respectively. At the end of 4 and 12 weeks, three rabbits from each group were sacrificed by applying high-dose anesthetic, and samples were examined histologically and immunohistochemically. RESULTS: Groups 2 and 5 showed significantly increased new bone formation compared with groups 1 and 4, 4 weeks after MSFA (P < .05). Twelve weeks after sinus floor augmentation, groups 2, 3, 5, and 6 showed significantly higher new bone formation than group 1 (P < .05). Groups 2 and 5 showed significantly higher hard tissue response than groups 1 and 4 at the end of 4 weeks (P < .05). Groups 5 and 6 demonstrated significantly higher hard tissue response than group 1 at the end of 12 weeks (P < .05). Group 5 also showed significantly higher hard tissue response than group 4 at the end of 12 weeks (P < .05). Immunohistochemical analysis showed a significant difference between the osteocalcin scores of groups 2 and 4 and group 1 at the end of 4 and 12 weeks (P < .05). There was also a statistically significant difference between osteocalcin scores at 4 and 12 weeks for groups 1 and 5 (P < .05). When osteopontin scores were compared, there was no significant difference between groups at 4 and 12 weeks (P > .05). Groups 1, 2, and 5 showed significant changes in osteopontin scores between 4 and 12 weeks (P < .05). CONCLUSION: The combination of ACC and PRP and the combination of ACC and EMD showed increased new bone formation and hard tissue response. A-PRF also showed promising results in new bone formation at the end of both 4 and 12 weeks. The usage of ACC as a carrier for liquid-form biomaterials may be more beneficial than the usage of ACC alone.

Ticagrelor alleviates high-carbohydrate intake induced altered electrical activity of ventricular cardiomyocytes by regulating sarcoplasmic reticulum-mitochondria miscommunication.

Metabolic syndrome (MetS) is associated with additional cardiovascular risk in mammalians while there are relationships between hyperglycemia-associated cardiovascular dysfunction and increased platelet P2Y12 receptor activation. Although P2Y12 receptor antagonist ticagrelor (Tica) plays roles in reduction of cardiovascular events, its beneficial mechanism remains poorly understood. Therefore, we aimed to clarify whether Tica can exert a direct protective effect in ventricular cardiomyocytes from high-carbohydrate diet-induced MetS rats, at least, through affecting sarcoplasmic reticulum (SR)-mitochondria (Mit) miscommunication. Tica treatment of MetS rats (150 mg/kg/day for 15 days) significantly reversed the altered parameters of action potentials by reversing sarcolemmal ionic currents carried by voltage-dependent Na+ and K+ channels, and Na+/Ca2+-exchanger in the cells, expressed P2Y12 receptors. The increased basal-cytosolic Ca2+ level and depressed SR Ca2+ load were also reversed in Tica-treated cells, at most, though recoveries in the phosphorylation levels of ryanodine receptors and phospholamban. Moreover, there were marked recoveries in Mit structure and function (including increases in both autophagosomes and fragmentations) together with recoveries in Mit proteins and the factors associated with Ca2+ transfer between SR-Mit. There were further significant recoveries in markers of both ER stress and oxidative stress. Taken into consideration the Tica-induced prevention of ER stress and mitochondrial dysfunction, our data provided an important document on the pleiotropic effects of Tica in the electrical activity of the cardiomyocytes from MetS rats. This protective effect seems through recoveries in SR-Mit miscommunication besides modulation of different sarcolemmal ion-channel activities, independent of P2Y12 receptor antagonism.

Comparison of Histological and Angiographic Measurements of the Basilar Artery in an Experimental Rabbit Subarachnoid Hemorrhage Model.

AIM: To compare the histological and angiographic measurements of the basilar artery in an experimental rabbit subarachnoid hemorrhage model. MATERIAL AND METHODS: The basilar artery was measured using both histological and angiographic methods in experimental subarachnoid hemorrhage (SAH) and vasospasm rabbit models. New Zealand white rabbits were randomly categorized into two groups: control and SAH groups. The SAH group rabbits were operated on to create an experimental SAH. Both groups were examined angiographic and histological methods. RESULTS: On comparing the two methods, angiographic and histopathological measurements of the basilar artery were similar in the control group. However, in the SAH group, the difference between the angiographic and histopathological measurement methods was significant. Histopathological measurements of the basilar artery were lower than angiographic measurements, and the difference was statistically significant. In the angiographic method, although there was a marked decrease in basilar artery measurements in the SAH group, the differences between the groups was not statistically significant. However, in the histopathological method, measurement differences between the control and SAH groups were statistically significant. CONCLUSION: Histopathological measurements were shown to be more sensitive than angiographic methods in demonstrating cerebral vasopasm in experimental SAH rabbit models.

What is the restorative effect of VEGF inhibitor bevacuzimab against subarachnoid hemorrhage in an experimental model?

BACKGROUND: This study investigated the effect of vascular endothelial growth factor (VEGF) inhibitor bevacuzimab (BVZ) on the rabbit basilar artery using an experimental subarachnoid hemorrhage (SAH) model. METHODS: Eighteen adult male New-Zealand white rabbits were randomly divided into three groups: a control group (n = 6), SAH group (n = 6), and SAH+BVZ group (n = 6). Experimental SAH was created by injecting autologous arterial blood into the cisterna magna. In the treatment group, the subjects were administered a daily dose of 10 mg/kg, intravenous BVZ for 2 days after the SAH. Basilar artery diameters were measured with magnetic resonance angiography (MRA) 72 h after the SAH in all groups. After 72 h, whole brains, including the upper cervical region, were obtained from all the animals after perfusion and fixation of the animal. The wall thickness, luminal area, and the apoptosis at the basilar arteries were evaluated in all groups. RESULTS: BVZ significantly prevented SAH-induced vasospasm confirmed in vivo with MRA imaging with additional suppression of apoptosis on basilar artery wall. DISCUSSION: VEGF inhibition with BVZ has shown to have a vasospasm and apoptosis attenuating effect on basilar artery in a SAH model.

Ageing-associated increase in SGLT2 disrupts mitochondrial/sarcoplasmic reticulum Ca2+ homeostasis and promotes cardiac dysfunction.

The prevalence of death from cardiovascular disease is significantly higher in elderly populations; the underlying factors that contribute to the age-associated decline in cardiac performance are poorly understood. Herein, we identify the involvement of sodium/glucose co-transporter gene (SGLT2) in disrupted cellular Ca2+ -homeostasis, and mitochondrial dysfunction in age-associated cardiac dysfunction. In contrast to younger rats (6-month of age), older rats (24-month of age) exhibited severe cardiac ultrastructural defects, including deformed, fragmented mitochondria with high electron densities. Cardiomyocytes isolated from aged rats demonstrated increased reactive oxygen species (ROS), loss of mitochondrial membrane potential and altered mitochondrial dynamics, compared with younger controls. Moreover, mitochondrial defects were accompanied by mitochondrial and cytosolic Ca2+ ([Ca2+ ]i ) overload, indicative of disrupted cellular Ca2+ -homeostasis. Interestingly, increased [Ca2+ ]i coincided with decreased phosphorylation of phospholamban (PLB) and contractility. Aged-cardiomyocytes also displayed high Na+ /Ca2+ -exchanger (NCX) activity and blood glucose levels compared with young-controls. Interestingly, the protein level of SGLT2 was dramatically increased in the aged cardiomyocytes. Moreover, SGLT2 inhibition was sufficient to restore age-associated defects in [Ca2+ ]i -homeostasis, PLB phosphorylation, NCX activity and mitochondrial Ca2+ -loading. Hence, the present data suggest that deregulated SGLT2 during ageing disrupts mitochondrial function and cardiac contractility through a mechanism that impinges upon [Ca2+ ]i -homeostasis. Our studies support the notion that interventions that modulate SGLT2-activity can provide benefits in maintaining [Ca2+ ]i and cardiac function with advanced age.

Evaluation of blood-testis barrier integrity in terms of adhesion molecules in nonobstructive azoospermia.

Blood-testis barrier (BTB) is critical for maintaining fertility. The integrity of tight junctions (TJs) provides restricted permeability of BTB. The aim of this study was to evaluate the relationship between BTB and Sertoli cells. Testicular sperm extraction (TESE) obtained from nonobstructive azoospermia (NOA) patients was examined: Group I (spermatozoa+) and Group II (spermatozoa-). The tissues were stained with haematoxylin eosin, periodic acid-Schiff and Masson's trichrome for Johnsen's score evaluation. Apoptosis and adhesion molecules such as claudin-11, occludin and ZO-1 were assessed. In Group I, the integrity of the seminiferous tubules was intact. In Group II, some seminiferous tubule walls were lined only with Sertoli cells, had a thickening of the basement membrane, and oedema in interstitial spaces. In Group I, the seminiferous tubule consisted of a stratified columnar epithelium, claudin-11 expressions were observed as linear staining in the basal zone of the tubule, while seminiferous tubules, with low epithelium, displayed a punctate type of staining. Immunohistochemical observations were consistent with the ultrastructural findings. In Group II, high apoptosis and unstained/irregular TJ formation in claudin-11, occludin and ZO-1 were observed. In conclusion, disruption of relation between BTB and TJs may reveal inadequate spermatogenesis, which is one of the mechanisms behind azoospermia.

Ticagrelor reverses the mitochondrial dysfunction through preventing accumulated autophagosomes-dependent apoptosis and ER stress in insulin-resistant H9c2 myocytes.

Ticagrelor, a P2Y12-receptor inhibitor, and a non-thienopyridine agent are used to treat diabetic patients via its effects on off-target mechanisms. However, the exact sub-cellular mechanisms by which ticagrelor exerts those effects remains to be elucidated. Accordingly, the present study aimed to examine whether ticagrelor influences directly the cardiomyocytes function under insulin resistance through affecting mitochondria-sarco(endo)plasmic reticulum (SER) cross-talk. Therefore, we analyzed the function and ultrastructure of mitochondria and SER in insulin resistance-mimicked (50-µM palmitic acid for 24-h) H9c2 cardiomyocytes in the presence or absence of ticagrelor (1-µM for 24-h). We found that ticagrelor treatment significantly prevented depolarization of mitochondrial membrane potential and increases in reactive oxygen species with a marked increase in the ATP level in insulin-resistant H9c2 cells. Ticagrelor treatment also reversed the increases in the resting level of free Ca2+ and mRNA level of P2Y12 receptors as well as preserved ER stress and apoptosis in insulin-resistant H9c2 cells. Furthermore, we determined marked repression with ticagrelor treatment in the increased number of autophagosomes and degeneration of mitochondrion, including swelling and loss of crista besides recoveries in enlargement and irregularity seen in SER in insulin-resistant H9c2 cells. Moreover, ticagrelor treatment could prevent the altered mRNA levels of Becklin-1 and type 1 equilibrative nucleoside transporter (ENT1), which are parallel to the preservation of ultrastructural ones. Our overall data demonstrated that ticagrelor can directly affect cardiomyocytes and provide marked protection against ER stress and dramatic induction of autophagosomes, and therefore, can alleviate the ER stress-induced oxidative stress increase and cell apoptosis during insulin resistance.

MitoTEMPO provides an antiarrhythmic effect in aged-rats through attenuation of mitochondrial reactive oxygen species.

The death prevalence from cardiovascular disease is significantly high in elderly-populations, while mitochondrial-aging plays an important in abnormal function of vital organs through high mitochondrial ROS production. Mitochondria have a unique mode of action by providing ATP production and modulating the cytosolic Ca2+-signaling and maintain the redox status of cardiomyocytes. There is an aging-associated impairment in oxidative phosphorylation which causes a marked dysregulation of mitochondrial biogenesis. Therefore, we aimed to examine whether a mitochondria-targeting antioxidant, MitoTEMPO, can directly provide a cardioprotective effect on ventricular cardiomyocyte function under in vitro conditions. The MitoTEMPO-treatment (0.1 µM for 4-h) of aged-ventricular cardiomyocytes (from 24-mo-old rats), compared to those of the adults (from 8-mo-old rats) markedly augmented not only the depressed biochemical parameters but also the ultrastructure of mitochondria. It also provided marked protective action against increased mitochondrial superoxide formation and Bnip3 overexpression, which both markedly induce depolarized mitochondrial potential, increase reactive oxygen species, mitochondrial swelling and fission, and accelerate mitochondrial turnover via autophagy. Furthermore, it provided marked protection against spontaneous action potentials, via shortening the prolonged action potential duration, at most, through recovery in depressed K+-channel currents. Moreover, we determined significant recovery in the depressed intracellular Ca2+-changes under electrical stimulation in MitoTEMPO-treated the aged-cardiomyocytes. Overall, we provided important information associated with an antiarrhythmic action, thereby controlling cytosolic and mitochondrial Ca2+-handling, implying its possible protective role of mitochondria-targeting antioxidant-treatment during aging.

Effects of eccentric exercise on different slopes.

OBJECTIVES: Eccentric contraction occurs when the muscle lengthens under tension. Damage-induced responses seen in the muscle after eccentric exercise usually experienced by sedentary individuals. This study aims to investigate muscle damage on different slopes. METHODS: 32 male Wistar albino rats randomly divided into four groups: sedentary, horizontal running, and eccentric exercise (-8°, -16°) groups. Animals ran for 90 min with the speed of 25 m/s for five days. After 48h from the last exercise, rats were sacrificed, and plasma creatine kinase (CK), heat shock protein 70 (HSP70) levels were examined. Plasma and soleus total oxidant/antioxidant status (TOS-TAS) and histological changes of soleus muscle assessed. RESULTS: CK and HSP70 significantly increased in 16° EE group. TOS increased at 16° EE and 8° EE, but oxidative stress index (OSI) was only high at 8° EE group. Mononuclear cell infiltration and the angiogenesis increased in soleus after eccentric exercise, and there was a correlation with slope. Sarcomere breaks were detected in 16° EE group also in a correlation with slope. CONCLUSIONS: Consequently, sedentary individuals are vulnerable to injuries induced by eccentric contraction. Therefore, our study provides information for reconsidering rehabilitation and training programs.