Intervention of curcumin and its analogue J7 on oxidative stress injury in testis of type 2 diabetic rats / 中国应用生理学杂志

OBJECTIVE@#To investigate the intervention of curcumin and its analogue J7 on oxidative stress injury in testis of type 2 diabetic rats.@*METHODS@#Sixty male SD rats, 10 rats were chosen as normal control group (NC), the other 50 rats were assigned to experiment group. Experiment diabetic rats were induced by high-fat food and intraperitoneal injection of steptozotocin (STZ). After the model was established successfully, diabetic rats were divided into four groups randomly: diabetes mellitus group (DM, n=12), curcumin treatment group (CUR, n=10), high dose treatment group of J7 (J+, n=10), low dose treatment group of J7 (J-, n=10). The CUR group were intragastrically administered with curcumin 20 mg/kg daily, in addition, the J+ group and the J- group were intragastrically administered with J7 20 mg/kg and 10 mg/kg daily respectively. After 8 weeks, the fast blood glucose was detected biochemically. The activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) were detected by hydroxylamine method and thiobarbituric acid method respectively. The protein expressions of the nuclear factor-erythroid 2-related factor 2 (tNrf2), phosphorylation of Nrf2 (pNrf2), catalase (CAT), NAD(P)H quinine oxidoreductase 1 (NQO1) were measured by Western blot. The mRNA expressions of CAT, NQO1, hemeoxygenase-1 (HO1) were measured by quantitative real-time PCR (qRT-PCR). Morphological structure of testis was observed by hematoxylin-eosin (HE) staining. The expressions of Nrf2 and CAT were also detected by immunohistochemical method.@*RESULTS@#The levels of fast blood glucose and MDA in DM group were increased significantly(P＜0.05), while the body weight, the activity of SOD, the protein expressions of pNrf2/tNrf2, CAT, NQO1 and the mRNA expressions of CAT, NQO1, HO1 were decreased (P＜0.05). Under light microscope, the DM group showed disrupted histological appearance. Immunohistochemistry showed that the protein expressions of Nrf2 around the nucleus and CAT were decreased. With the treatment of curcumin and J7, the MDA levels in the three treatment groups were decreased (P＜0.05). The activity of SOD, the protein expressions of pNrf2/tNrf2, CAT, NQO1 and the mRNA expressions of NQO1, HO1 were increased (P＜0.05). the levels of fast blood glucose were decreased in the J+ and J- group (P＜0.05), and the mRNA expression of CAT was increased in the J+ group (P＜0.05). The ratio of pNrf2/tNrf2 in the J+ group was significantly higher than that in CUR and J- group (P＜0.05). The protein level of CAT in the J+ group was also significantly higher than that in J- group (P＜0.05). There were no significant differences in other indexes among the three treatment groups. Under light microscope, the morphology was obviously improved in the three treatment groups. Immunohistochemistry showed that the protein expressions of Nrf2 around the nucleus and CAT were increased in the three treatment groups. It was suggested that high dose J7 had better antioxidant stress ability in testis of diabetic rats.@*CONCLUSION@#Curcumin and J7 could inhibit the oxidative stress damage of testicular tissue in diabetic rats, which might be related with the activation of the Nrf2-ARE signaling pathway.

Brain-Derived Glia Maturation Factor β Participates in Lung Injury Induced by Acute Cerebral Ischemia by Increasing ROS in Endothelial Cells / 神经科学通报·英文版

Brain damage can cause lung injury. To explore the mechanism underlying the lung injury induced by acute cerebral ischemia (ACI), we established a middle cerebral artery occlusion (MCAO) model in male Sprague-Dawley rats. We focused on glia maturation factor β (GMFB) based on quantitative analysis of the global rat serum proteome. Polymerase chain reaction, western blotting, and immunofluorescence revealed that GMFB was over-expressed in astrocytes in the brains of rats subjected to MCAO. We cultured rat primary astrocytes and confirmed that GMFB was also up-regulated in primary astrocytes after oxygen-glucose deprivation (OGD). We subjected the primary astrocytes to Gmfb RNA interference before OGD and collected the conditioned medium (CM) after OGD. We then used the CM to culture pulmonary microvascular endothelial cells (PMVECs) acquired in advance and assessed their status. The viability of the PMVECs improved significantly when Gmfb was blocked. Moreover, ELISA assays revealed an elevation in GMFB concentration in the medium after OGD. Cell cultures containing recombinant GMFB showed increased levels of reactive oxygen species and a deterioration in the state of the cells. In conclusion, GMFB is up-regulated in astrocytes after ACI, and brain-derived GMFB damages PMVECs by increasing reactive oxygen species. GMFB might thus be an initiator of the lung injury induced by ACI.

Contralateral head leading turning accompanied by ipsilateral eye staring in a patient with seizure onset from posterior inferior temporal sulcus, a SEEG case report

The epileptic eye and head movements during epileptic seizures may be much more complicated thanpeople originally understood, which can be ipsilateral or contralateral to the electroencephalographyfocus. Here, we describe a male patient with drug resistant focal seizures associated with a directionalseparation between head and eye movement before evolving into generalized tonic-clonic seizure.His contralateral head leading turning showed forced, sustained, and unnatural features companiedby ipsilateral eye staring. Stereoeletroencephalography monitoring was performed, and 4 habitualseizures were recorded over 5 days. Three seizures showed left head leading turning and generalizedtonic-clonic seizure, and only one showed dizziness and ringing in the ears. All the seizures showedthat the ictal onset contacts were located in the posterior inferior temporal sulcus which borders onthe anterolateral part of medial superior temporal area. The patient underwent a resection includingtemporooccipital region, and the histopathology showed focal cortical dysplasia type Ic. He has beenseizure free for two years after operation. The scores of the intelligence and memory quotient improvedhalf year after operation.

Calreticulin translocation aggravates endoplasmic reticulum stress-associated apoptosis during cardiomyocyte hypoxia/reoxygenation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Calreticulin (CRT) is major Ca 2+ -binding chaperone mainly resident in the endoplasmic reticulum (ER) lumen. Recently, it has been shown that non-ER CRT regulates a wide array of cellular responses. We previously found that CRT was up-regulated during hypoxia/reoxygenation (H/R) and this study was aimed to investigate whether CRT nuclear translocation aggravates ER stress (ERS)-associated apoptosis during H/R injury in neonatal rat cardiomyocytes.</p><p><b>METHODS</b>Apoptosis rate and lactate dehydrogenase (LDH) leakage in culture medium were measured as indices of cell injury. Immunofluorescence staining showed the morphological changes of ER and intracellular translocation of CRT. Western blotting or reverse transcription polymerase chain reaction was used to detect the expression of target molecules.</p><p><b>RESULTS</b>Compared with control, H/R increased apoptosis rate and LDH activity. The ER became condensed and bubbled, and CRT translocated to the nucleus. Western blotting showed up-regulation of CRT, Nrf2, activating transcription factor 4 (ATF4), CHOP and caspase-12 expression after H/R. Exogenous CRT overexpression induced by plasmid transfection before H/R increased cell apoptosis, LDH leakage, ER disorder, CRT nuclear translocation and the expression of ERS-associated molecules. However, administration of the ERS inhibitor, taurine, or CRT siRNA alleviated cell injury, ER disorder, and inhibited ERS-associated apoptosis.</p><p><b>CONCLUSIONS</b>Our results indicated that during H/R stress, CRT translocation increases cell apoptosis and LDH leakage, aggravates ER disorder, up-regulates expression of nuclear transcription factors, Nrf2 and ATF4, and activates ERS-associated apoptosis.</p>

Optimization of conditions for human erythropoiesis in human-mouse xenotransplant model / 中国实验血液学杂志

This study was purposed to investigate the conditions for improving human-mouse xenograft and the erythroid differentiation of human hematopoietic stem cells (HSC) in the xenotransplant model. The engraftments of different mouse strains (NOD/SCID or NOD/SCID/IL2rγ(null)), schemes of irradiation (single-time or 2-times radiation; Co(60)γ-ray or X-ray) and strategies of CB CD34(+) cells ex vivo culture time and lentivirus infection were compared. The results showed that at 4 weeks after transplantation, the ratio of hCD45 positive cells in bone marrow of NOD/SCID/IL2rγ(null) mice increased to (51.4 ± 13.9)%, and erythroid precursor could be detected. All of the mice receiving X-ray irradiation for 2 times (a dose of 1 Gy, then the second of 1.5 Gy, with an interval of 15 min) survived. Fresh isolated CB CD34(+) cells were cultured and infected with lentivirus for 72 h and then transplanted into receptor mouse. After 4 weeks, higher engraftment [hCD45 (51.4 ± 13.9)%] and better erythroid development [hCD71(+) GPA(+) (5.98 ± 3.46)%] were observed. It is concluded that NOD/SCID/IL2rγ(null) mice receiving X-ray irradiation for 2 times and were injected with fresh isolated CB CD34(+) cells cultured and infected with lentivirus ex vivo within 72 h show a better xenograft and erythroid development.

Cardioprotective mechanism of calreticulin up-regulation induced by hypoxic postconditioning / 生理学报

Calreticulin (CRT) is an essential Ca(2+)-binding chaperone existing in endoplasmic reticulum (ER) or sarcoplasmic reticulum (SR), and is involved in intracellular Ca(2+) homeostasis and protein folding. Ischemic postconditioning (I-postC), a newly discovered endogenous protective phenomenon, induces CRT up-regulation. The present study aimed to investigate the cardioprotective mechanism of CRT up-regulation induced by hypoxic postconditioning (H-postC). Primary cultured neonatal rat cardiomyocytes were exposed to 2 h of hypoxia followed by 24 h of reoxygenation. Postconditioning was carried out by two cycles of 10 min of reoxygenation and 20 min of rehypoxia after 2 h of hypoxia. Antisense oligodeoxynucleotides (AS-ODNs) were used to inhibit CRT expression 36 h before hypoxia. Cardiomyocytes were randomly divided into 6 groups as follows (n=4): control, hypoxia/reoxygenation (H/R), H-postC, AS, AS + H/R, and AS + H-postC. Morphological studies, lactate dehydrogenase (LDH) activity assay in culture medium, and flow cytometry were used to detect cardiomyocyte necrosis and apoptosis. Intracellular Ca(2+) concentration was detected by fluorescent Fluo-3/AM staining through laser confocal microscope, and p-nitrophenyl phosphate (PNPP) was used as substrate to measure calcineurin (CaN) activity. The expression of CRT, CaN, nuclear factor kappa B (NFκB) and apoptosis-related proteins, such as Bcl-2, Bax and C/EBP homologous protein (CHOP) were detected by Western blot. The results were as follows. (1) H-postC protected neonatal cardiomyocytes from H/R injury. Compared with H/R group, cell survival rate increased by 17.1%, apoptotic rate and LDH leakage decreased by 6.67% and 27.9% in H-postC group, respectively (P<0.05). (2) H-postC induced mild up-regulation of CRT expression. Inhibition of CRT by AS-ODNs attenuated the cardioprotection of H-postC partly. Compared with H-postC group, cell survival rate decreased by 8.98%, and apoptotic rate and LDH leakage increased by 1.74% and 13.6% in AS + H-postC group, respectively (P<0.05), but intracellular Ca(2+) concentration, CaN activity, and expression of CaN and NFκB did not change significantly (P>0.05), suggesting that CRT participates in endogenous protection, not through Ca(2+)-CaN pathway. (3) H-postC inhibited the expression of pro-apoptosis proteins such as Bax and CHOP, but induced up-regulation of anti-apoptosis protein Bcl-2. Inhibition of CRT by AS-ODNs partly inhibited the changes in apoptosis-related proteins expression induced by H-postC, suggesting that CRT participates in the anti-apoptosis effect of H-postC through regulating expression of apoptosis-related proteins. These results indicate that CRT up-regulation induced by H-postC is involved in the cardioprotection through regulating expression of apoptosis-related proteins, not through Ca(2+)-CaN pathway in neonatal cardiomyocytes.

Calreticulin upregulation induced by hypoxic preconditioning relieves oxidative stress injury in rat cardiomyocytes / 生理学报

The present study was aimed to investigate whether calreticulin (CRT) was involved in the protective effect of hypoxic preconditioning (HPC) against oxidative stress injury in rat cardiomyocytes. Neonatal cardiomyocytes were prepared from Sprague-Dawley rats aged 24 h, and cultured in DMEM medium containing 10% fetal bovine serum. The cultured cardiomyocytes were randomly divided into 8 groups as follows: (1) hydrogen peroxide stress (H(2)O(2) group); (2) brief hypoxic exposure for 20 min to simulate HPC (HPC group); (3) hypoxic exposure for 20 min followed by normoxic reoxygenation for 24 h before hydrogen peroxide stress (HPC + H(2)O(2) group); (4) SB203580 (a specific inhibitor of p38 MAPK) + HPC + H(2)O(2) group; (5) CRT antisense oligonucleotide transfection (AS group); (6) AS + H(2)O(2) group; (7) AS + HPC + H(2)O(2) group; (8) control group. Morphological observation, lactate dehydrogenase (LDH) leakage and flow cytometry were employed to assess cell apoptosis and necrosis. RT-PCR and Western blot were used to detect CRT expression and activity of p38 MAPK. All experiments were repeated at least four separate times. The results obtained were as follows: (1) HPC relieved cell injury caused by H(2)O(2). Compared with that in H(2)O(2) group, the cell survival rate increased by 18.0% (P<0.05), apoptotic rate and LDH leakage in culture medium decreased by 19.4% and 53.0%, respectively (P<0.05) in HPC + H(2)O(2) group. (2) H(2)O(2) induced CRT over-expression (7.1-fold increase compared with control, P<0.05), while HPC resulted in mild CRT up-regulation (2.4-fold increase compared with control, P<0.05), suggesting that HPC can relieve the over-expression of CRT induced by H(2)O(2). (3) CRT AS transfection weakened the protection of HPC. Compared with that in HPC + H(2)O(2) group, the cell survival rate decreased by 4% (P<0.05), and apoptotic rate and LDH leakage in culture medium increased by 2.6% and 39.0%, respectively (P< 0.05) in AS + HPC + H(2)O(2) group. (4) The protection of HPC and HPC-induced upregulation of CRT were almost eliminated when SB203580 was administered before HPC. These results suggest that HPC up-regulates CRT expression through the p38 MAPK signaling pathway and protects cardiomyocytes from oxidative stress injury.

Hypoxic preconditioning induces endoplasmic reticulum stress-related cardioprotection mediated by p38 mitogen-activated protein kinase / 生理学报

Calreticulin (CRT), an important Ca(2+)-binding molecular chaperone in the endoplasmic reticulum (ER), and caspase-12, a pivotal molecule mediating ER-initiated apoptosis, are involved in the ER stress (ERS). Using primary cultured neonatal cardiomyocytes, CRT and caspase-12 expression and activation during hypoxic preconditioning (HPC) and hypoxia/reoxygenation (H/R) were studied to explore the role of ERS in cardioprotection by HPC. And by using SB203580 and SP600125 [the specific inhibitors of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK)] separately, the role of p38 MAPK in HPC-induced ERS was also detected. Neonatal cardiomyocytes were prepared from Sprague-Dawley rats aged 24 h, and cultured in DMEM medium containing 10% fetal bovine serum, and then randomly divided into six groups as follows: H/R, HPC+H/R, SB203580+HPC+H/R, SP600125+HPC+H/R, HPC and control groups. H/R was produced by 2-hour hypoxia/14-hour reoxygenation, and HPC by 20-minute hypoxia/24-hour reoxygenation. Morphological studies, estimation of lactate dehydrogenase (LDH) leakage and flow cytometry were employed to assess cell apoptosis and necrosis. CRT and caspase-12 expression and activation, levels of phospho-p38 MAPK and phospho-JNK were detected by Western blot. All experiments were repeated at least four separate times. The results obtained are as follows: (1) HPC relieved the cell injury caused by H/R. Compared with that in H/R group, cellso survival rate in HPC+H/R group increased by 6.4%, and the apoptosis rate and LDH leakage in the cell culture medium decreased by 6.6% and 70.0%, respectively. (2) H/R induced caspase-12 activation (33.2-fold increase in comparison with control) and CRT expression (8.1-fold increase in comparison with control). HPC itself resulted in mild CRT up-regulation (2.6-fold increase in comparison with control), but the extent of up-regulation was lower than that induced by H/R. HPC before H/R was found to relieve the over-expression of CRT induced by H/R (72.4% decrease), and to inhibit the activation of caspase-12 (59.6% decrease). (3) The protection of HPC and HPC-induced up-expression of CRT and inhibition of caspase-12 activation were almost eliminated when the inhibitor of p38 MAPK, not of JNK, was present before HPC. These results suggest that HPC protects the neonatal cardiomyocytes from severe ERS-induced apoptosis during sustained H/R through pre-invoking proper ERS response. Mild up-expression of CRT and inhibition of caspase-12 activation induced by HPC, which are important protection factors, are mediated by p38 MAPK, not by JNK.

Calreticulin expression increases during delayed cardioprotection induced by hypoxic preconditioning / 生理学报

Both in vivo and cultured cardiomyocyte experiments were performed to investigate the alteration of expression of calreticulin (CRT) during the delayed cardioprotection induced by hypoxic preconditioning (HPC) and the intracellular signal transduction mechanisms of the alteration. (1) Wistar rats were randomly divided into three groups: sham operation group (Sham), myocardial infarction (MI) group induced by left coronary artery ligation and HPC+MI group (4-hour HPC 24 h before MI). Twenty-four hours, 14 d and 28 d after left coronary artery ligation, myocardial function, infarction size and the area at risk were measured. Western blot was used to detect the expression of CRT, the activity of p38 mitogen-activated protein kinase (MAPK) and stress-activated protein kinase (SAPK). (2) Cultured cardiomyocytes from neonatal Sprague-Dawley (SD) rat were divided into six groups: hypoxia/reoxygenation (H/R), HPC, HPC+H/R, p38 MAPK inhibitor SB203580+HPC+H/R (SB+HPC+H/R), SAPK inhibitor SP600125+HPC+H/R (SP+HPC+H/R) and control. Survival rate and apoptosis rate of cardiomyocytes 6 h after H/R and activities of lactate dehydrogenase (LDH) in culture medium in each group were measured. Western blot was used to detect the expression of CRT and activities of p38 MAPK and SAPK. The results are as follows: (1) During in vivo experiment, compared with MI group, HPC significantly improved +dp/dt(max) and -dp/dt(max), reduced infarction size and the area at risk. HPC dramatically changed the expression of CRT. CRT expression in HPC+MI group was 206% of that in MI group (P<0.05) 24 h after infarction, especially in the area at risk. However, 28 d after operation, the expression of CRT decreased by 57%. Correlation analysis indicated a positive correlation between CRT expression and myocardial function (r=0.9867, P<0.05), and negative correlation between CRT expression and infarction size (r=-0.9709, P<0.05). (2) In cultured cardiomyocytes, HPC attenuated cell injury induced by H/R. CRT expression increased moderately to 222% of control (P<0.05) during HPC, but increased dramatically to 503% of control (P<0.05) after H/R. HPC reduced H/R-induced CRT up-regulation to 56% of that in H/R group (P<0.05). Correlation analysis indicated that CRT expression induced by HPC had a positive correlation with p38 MAPK activity (r=0.9021, P<0.05), but a negative correlation with SAPK activity (r=-0.8211, P<0.05). Both in vivo and in vitro results indicate that HPC protects myocardium from ischemia or H/R injury. p38 MAPK is possibly involved in the up-regulation of CRT induced by HPC, while SAPK has a negative influence.

Role of hypoxia-inducible factor-1alpha in the prevention of cardiomyocyte injury induced by hypoxic preconditioning / 生理学报

In order to understand the intracellular mechanism of preconditioning, we investigated the relationship among activities of extracellular signal-regulated protein kinases (ERKs), the expression of hypoxia-inducible factor -1alpha (HIF-1alpha) and the effect of hypoxic preconditioning (HPC) on cell injury induced by hypoxia-reoxygenation in cultured neonatal rat cardiomyocytes 24 h after brief hypoxia. Cultured cardiomyocytes of neonatal Sprague-Dawley rats were divided into four groups: hypoxia/reoxygenation (H/R), hypoxia preconditioning (HPC), hypoxia preconditioning + mitogen-activated protein kinase (MAPK) inhibitor PD98059 (HPC+PD98059), and control (C). We measured the survival rate and apoptosis rate of cardiomyocytes at 6 or 12 h after hypoxia/reoxygenation, activities of extracellular signal-regulated protein kinases (ERKs), and expression of hypoxia-inducible factor-1alpha (HIF-1alpha). We found that the survival rate of cardiomyocytes in hypoxic preconditioning group increased by 6.08% and 7.91% at 6 and 12 h after hypoxia/reoxygenation (n=6, P<0.05), respectively, and the apoptotic rate decreased by 10.92% and 14.34% (n=6, P<0.05) respectively. Hypoxic preconditioning increased the abundance of phospho-ERK1/2 by 3-folds and expression of HIF-1alpha by 1-fold in whole cell extracts from hypoxic preconditioned cardiomyocytes. PD98059, an inhibitor of the upstream kinase of ERKs, abolished the anti-injury effect, ERKs activation, and expression of HIF-1alpha induced by hypoxic preconditioning. Statistical analysis indicated that there was negative correlation between apoptotic rate and activities of ERKs or expression of HIF-1alpha, and positive correlation between activities of ERKs and expression of HIF-1alpha. It is concluded that hypoxic preconditioning protects cardiomyocytes from hypoxia/reoxygenation-induced injury and that upregulation of HIF-1alpha through ERKs pathway mediates the cardioprotection of hypoxic preconditioning.