Selenium nanoparticles reduce oxidative stress-induced cardiomyocyte apoptosis in ascites syndrome in broiler chickens via the ATF6-DR5 signaling pathway

Broiler ascites syndrome(AS)is one of the main diseases threatening the health of broilers.It is well documented that myocardial hypertrophy and failure is one of the key mechanisms of broiler ascites syndrome.Therefore,prevention of cardiac hypertrophy and failure would be one goal to reduce broiler ascites syndrome incidence.Myocardial hyper-trophy and failure are closely related to endoplasmic reticulum stress(ERS)in cardiac myocytes,and the endoplasmic reticulum stress signaling system(ATF6-DR5)is one of the important pathways of myocardial apoptosis.Excessive hyper-trophy will affect the heart muscle's normal contraction and diastole function,and the heart will turn from compen-sated to decompensate thus causing myocardial injury.Myocardial apoptosis is a core component of the pathological changes of this myocardial injury.Nano-selenium is a kind of red elemental selenium nanoparticle.Due to its excellent physical,chemical and biological properties,it has attracted extensive academic attention in recent years.It has been proven to have excellent antioxidant,antibacterial,antitumor,antihypertrophic,and antiapoptotic abilties.Herein,nano-selenium(1μmol/L)can inhibit hydrogen peroxide(H_(2)O_(2))-induced oxidative stress in broiler primary cardiomyocytes,and at the same time reduce cardiomyocyte apoptosis.In vivo,nano-selenium can reduce broiler myocardial injury-related enzyme indicators(AST,CK and LDH),and alleviate myocardial injury.It can also activate the antioxidant enzyme system(SOD,GSH-Px and CAT)and reduce MDA,and make the recovery ofT-AOC ability in the organization.Meanwhile,nano-selenium can down-regulate the genes and proteins expression of ATF-6,GRP-78,CHOP and caspase 12 in the ERS-related signaling pathway,and inhibit that of downstream-related caspase 3,Bax and caspase 9,and increase that of the downstream anti-apoptotic Bcl-2,thereby maintaining the homeostasis of the endoplasmic reticulum and alleviating cardiomyocyte apoptosis.It can be seen that nano-selenium can protect the damaged myocardium in the broiler ascites caused by high-salt drinking by regulating the ATF6-DR5 signaling pathway.This study was performed in chickens and cardiomyocyte cells and attempted to demonstrate that selenium nanoparticles can protect the damaged myocar-dium in broiler ascites.This paper provides a new idea for preventing and treating broiler ascites syndrome.

Panax quinquefolium saponin attenuates cardiomyocyte apoptosis induced by thapsigargin through inhibition of endoplasmic reticulum stress

Background Endoplasmic reticulum （ER） stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin （PQS） is able to inhibit excessive ER stress-related apoptosis of cardiomyocytes following hypoxia/reoxygenation and myocardial infarction. However, the pathway by which PQS inhibits the ER stress-related apoptosis is not well understood. To further investigate the protective effect of PQS against ER stress-related apoptosis, primary cultured eardiomyocytes were stimulated with thapsigargin （TG）, which is widely used to model cellular ER stress, and it could induce apoptotic cell death in sufficient concentration. Methods Primary cultured cardiomyocytes from neonatal rats were exposed to TG （1 μmol/L） treatment for 24 h, following PQS pre-treatment （160 μg/mL） for 24 h or pre-treatment with small interfering RNA directed against protein kinase-like endoplasmic reticulum kinase （Si-PERK） for 6 h. The viability and apoptosis rate of cardiomyocytes were detected by cell counting kit-8 and flow cytometry respectively. ER stress-related protein expression, such as glucose-regulated protein 78 （GRP78）, calreticulin, PERK, eukaryotic translation initiation factor 2α （elF2c0, activating transcription factor 4 （ATF4）, and C/EBP homologous protein （CHOP） were assayed by western blotting. Results Both PQS pre-treatment and PERK knockdown remarkably inhibited the cardiomyocyte apoptosis induced by TG, increased cell viability, decreased phosphorylation of both PERK and eIF2α, and decreased protein levels of both ATF4 and CHOP. There was no statistically significant difference between PQS pre-treatment and PERK knockdown in the cardioprotective effect. Conclusions Our data indicate that the PERK-eIF2α-ATF4-CHOP pathway of ER stress is involved in the apoptosis induced by TG, and PQS might prevent TG-induced cardiomyocyte apoptosis through a mechanism involving the suppression of this pathway. These findings provide novel data regarding the molecular mechanisms by which PQS inhibits cardiomyocyte apoptosis.

Effectof Ginsenoside Re on Cardiomyocyte Apoptosis and Expression of Bcl-2/Bax Gene after Ischemia and Reperfusion in Rats

To observe the effectof ginsenoside Re on cardiomyocyte apoptosis and Bcl- 2 / Bax gene expression after ischemia (30 m in) and reperfusion (6 h) in rats and to elucidate the possible m echanism s of ginsenoside Re on inhibition of cardiom yocyte apoptosis,the ischem ia/ reperfusion heart m odel was established by ligating the left anterior descending branch of coronary artery in Wistar rats.The apoptotic cardiom yocytes were confirmed by transm ission electron m icroscopy and counted by in situ nick end labeling(TU NEL) method and lightm icroscopy.The m RNA and protein expression of Bcl- 2 and Bax genes were studied by in situ hybridization and im munohis- tochemical staining.Mean optical density (OD) value of the positive fields of m RNA and protein expression was quantitatively exam ined by im age analysis system.The results were as follows: (1) The apoptotic cardiomyocytes were found in ischemic fields in the ischem ia/ reperfusion group and weren't observed in the sham- operation group by transmission electron microscopy;(2 ) The num bers of the apoptotic cells were134.4 5± 4 5 .6 1/ field in the ischemia/ reperfusion group,and 90 .6 6± 19.2 2 / field in the ginsenoside Re- treated group.The differences was significant between two groups(P<0 .0 1) ;(3) Gene expression of Bcl- 2 and Bax were increased significantly in the is- chemia/ reperfusion group and ginsenoside Re- treated group when compared with the sham - opera- tion group.There was no significant difference in the gene expression of Bcl- 2 between the gin- senoside Re- treated group and ischemia/ reperfusion group(P>0 .0 5 ) ,but gene expression of Bax was decreased significantly in the ginsenoside Re- treated group as compared with the ischem ia/ reperfusion group(P<0 .0 1) .The ratio of Bcl- 2 / Bax was increased significantly in the ginseno- side Re- treated group when com pared with the ischem ia/ reperfusion group and sham- operation group.These findings suggest that m yocardial ischem ia- reperfusion can induce cardiom yocyte apoptosis,and ginsenoside Re can significantly inhibit cardiom yocyte apoptosis induced by ischemi- a- reperfusion in rats.It is concluded that ginsenoside Re inhibits cardiomyocyte apoptosis by in- hibiting expression of pro- apoptotic Bax gene and raising the ratio of Bcl- 2 / Bax.

Study on the Effects of Losartan on Cardiomyocyte Apoptosis and Gene Expression After Ischemia and Reperfusion in vivo in Rats

Summary: In order to study the effects of losartan on cardiomyocyte apoptosis following ischemia (0. 5 h) and reperfusion (48 h) in vivo and bcl-2 and bax gene expression, TUNEL staining method, immunohistochemistry and in situ hybridization histochemistry (ISHH) were used to monitor the apoptotic cells, mRNA and protein of gene expression, respectively. Image processing system was used to quantitively dispose the positive metric substance of both immunohistochemistry and ISHH through the average optical density (OD) value. The number of the apop- totic cells were 38±9 (control group), 0-1 (sham operation group) and 9±4 (losartan-treated group) in each visual field respectively with the difference among the groups being significant (P< 0. 001 ). OD values of bcl-2 (ISHH) were 0. 07425± 0. 02029 (control group ), 0. 05961± 0. 009932 (sham operation group) and 0. 07619±0. 01445 (losartan-treated group ) respectively, while OD values of bcl-2 (immunohistochemistry) were 0. 1374±0. 01367 (control group ), 0. 08510±0. 01862 (sham operation group) and 0. 1252±0. 02064 (losartan-treated group). hcl-2 gene expression was increased significantly in the control group and losartan-treated group as com- pared with sham operation group (P < 0. 05 ). OD value of bax (immunohistochemistry) was 09727±0. 02230 (control group), 0. 06182±0. 01430 (sham operation group) and 0. 06213± 0. 01420 (losartan-treated group). bax gene expression was decreased very significantly in losartan-treated group and sham operation group as compared with control group (P<0. 001 ). Bcl-2/ bax ratio was 1. 413 (control group), 1. 376 (sham operation group) and 2. 016 (losartan-treated group) respectively. The results indicated that losartan might inhibit cardiomyocyte apoptosis following ischemia and reperfusion. The mechanism might be that bax gene expression was inhibited to increase bcl-2/bax ratio.

APEX1 protects against oxidative damage-induced cardiomyocyte apoptosis

Apurine/pyrimidine-free endonuclease 1(APEX1)is a multifunctional enzyme that contributes to oxidization-mediated DNA-cleaved base excision repair and redox activation of transcription factors.However,the role of APEX1 during cardiomyocyte oxidative stress injury is not completely understood.In the present study,whether APEX1 protects oxidative damage-induced cardiomyocytes was investigated.mRNA and protein expression levels of APEX1 were downregulated in the mouse model of cardiac ischemia-reperfusion injury.Furthermore,the expression of APEX1 in hydrogen peroxide(H 2 O 2)-treated neonatal mice cardiomyocytes was also decreased.APEX1 knockdown aggravated H 2 O 2-treated cardiomyocyte apoptosis indexes.By contrast,APEX1 overexpression reversed H 2 O 2-induced oxidative damage,as demonstrated by decreased caspase 3 and Bax expression levels.Moreover,homeobox A5 upregulated APEX1.The results of the present study indicated that APEX1 displayed protective effects against oxidative damage,suggesting that APEX1 may serve as a unique protective strategy for cardiac ischemia-reperfusion injury.

miR-133 contributes to high glucose-induced cardiomyocyte apoptosis via IGF1 receptor

MicroRNAs(miRNAs) are endogenous 20 -23 -nucleotide (nt) -containing small non-coding RNAs that negatively regulate gene expression in diverse biological and pathological processes,including cell differentiation,proliferation, apoptosis,heart disease and human cancers.We investigated miR-133 expression and its potential role in a high glucose-induced myocardium in Streptozotocin(STZ)-induced C57bl6 mouse model of diabetes.miR-133 expression was significantly increased in myocardium in a time-dependent manner after STZ treatment.IGF1 receptor(IGF1R) protein was dramatically decreased without obvious up-regulation of its mRNA level post hyperglycemia.IGF1R protein level was decreaed with increase of its transcript level in neonatal mouse ventricular cardiomyocytes induced by high D-glucose concentration. Dual luciferase assay revealed that miR133 could interact with specific sites in the 3’UTR of IGF1R gene.p-ERK and p-Akt levels were reduced in neonatal mouse cardiomyocytes over-expressed with miR133 after IGF treatment.Introduction of functional miR-133,IGF1R siRNA into neonatal mouse cardiomyocytes could enhance cardiomyocyte apoptosis.These results implicate that miR-133 is involved in contributing to high glucose-induced cardiomyocyte apoptosis via regulating IGF1R expression post-transcriptionally.

Early initiation of ARBs without blood pressure risk via neutrophil membrane-fused pH-sensitive liposomes to reduce cardiomyocyte apoptosis after acute myocardial infarction

Activation of the local renin-angiotensin system(RAS)promotes cardiomyocyte apoptosis and cardiac remodeling after acute myocardial infarction(AMI).As an anti-RAS drug,the effect of Valsartan in the early stage of acute MI is limited by its low drug concentration in the heart and low dosage.Here,by exploiting the inherent nature of neutrophils migrating to the injured myocardium and the local low-pH microenvironment caused by ischemia and hypoxia after myocardial infarction,we designed nanocarrier(NSLP)-hybridized neutrophil membranes and pH-sensitive liposomes(SLPs)for the delivery of Valsartan(NSLPVal).These functional nanocarriers could mimic neutrophils and are homed to the injured heart;they were also found to respond to a low-pH microenvironment.In the mouse model of MI,we found that NSLP-Val could target the infarct marginal zone and release Valsartan locally in the low-pH microenvironment without affecting hemodynamic stability.Further,locally released angiotensin receptor inhibitors reduced the infarct size and inflammatory response by inhibiting cardiomyocytes.Ultimately,NSLP-Val improved cardiac function and inhibited cardiac hypertrophy and fibrosis.

β3-adrenoceptor Impacts Apoptosis in Cultured Cardiomyocytes via Activation of PI3K/Akt and p38MAPK

β3-adrenoceptor（β3-AR） has been shown to promote myocardial apoptosis. However, the exact physiological role and importance of this receptor in the human myocardium, and its underlying mode of action, have not been fully elucidated. The present study aimed to determine the effects of β3-AR on the promotion of myocardial apoptosis and on norepinephrine（NE） injury. We analyzed NE-induced cardiomyocyte（CM） apoptosis by using a TUNEL and an annexin V/propidium iodide apoptosis assay. Furthermore, we investigated the NE-induced expression of the apoptosis marker genes Akt and p38 MAPK, their phosphorylated counterparts p-Akt and p-p38 MAPK, caspase-3, Bcl-2, and Bax. In addition, we determined the effect of a 48-h treatment with a β3-AR agonist and antagonist on expression of these marker genes. β3-AR overexpression was found to increase CM apoptosis, accompanied by an increased expression of caspase-3, bax/bcl-2, and p-p38 MAPK. In contrast, the β3-blocker reduced apoptosis of CMs and the associated elevated Akt expression. We identified a novel and potent anti-apoptosis mechanism via the PI3K/Akt pathway and a pro-apoptosis pathway mediated by p38 MAPK.

Mechanism of adipose-derived mesenchymal stem cell exosomes in the treatment of heart failure

BACKGROUND Heart failure(HF)is a global health problem characterized by impaired heart function.Cardiac remodeling and cell death contribute to the development of HF.Although treatments such as digoxin and angiotensin receptor blocker drugs have been used,their effectiveness in reducing mortality is uncertain.Researchers are exploring the use of adipose-derived mesenchymal stem cell(ADMSC)exosomes(Exos)as a potential therapy for HF.These vesicles,secreted by cells,may aid in tissue repair and regulation of inflammation and immune responses.However,further investigation is needed to understand the specific role of these vesicles in HF treatment.AIM To investigate the mechanism of extracellular vesicles produced by ADMSC s in the treatment of HF.METHODS Exogenous surface markers of ADMSCs were found,and ADMSCs were cultured.RESULTS The identification of surface markers showed that the surface markers CD44 and CD29 of adipose-derived stem cells(ADSCs)were well expressed,while the surface markers CD45 and CD34 of ADSCs were negative,so the cultured cells were considered ADSCs.Western blotting detected the Exo surface marker protein,which expressed CD63 protein but did not express calnexin protein,indicating that ADSC-derived Exos were successfully extracted.CONCLUSION The secretion of MSCs from adipose tissue can increase ATP levels,block cardiomyocyte apoptosis,and enhance the heart function of animals susceptible to HF.The inhibition of Bax,caspase-3 and p53 protein expression may be related to this process.

Inhibition of TGF-β1 by eNOS gene transfer provides cardiac protection after myocardial infarction

Objective： Endothelial nitric oxide synthase （eNOS） and nitric oxide （NO） have been implicated in protection against myocardial ischemia injury. This study was designed to explore a new method of therapy for myocardial injury by eNOS gene transfection. Methods： A rat model of myocardial infarction （MI） was established by left anterior descending （LAD） coronary artery ligation, eNOS gene in an adenovirus vector was delivered locally into the rat heart and hemodynamic parameters were examined after 3 weeks, Matrix metalloproteinase-2 and 9 （MMP-2, MMP-9） mRNA were measured by reverse transcription polymerase chain reaction （RT-PCR）, and the protein levels of eNOS, caspase-3, and transforming grouth factor 131 （TGF-131） were determined by western blot assay. Results： eNOS gene transfer significantly reduced cardiomyocyte apoptosis and improved cardiac function. In addition, eNOS significantly reduced the mRNA levels of MMP-2 and MMP-9. In the eNOS gene transfected group, the activation of caspase-3 and TGF-β1 were decreased. However, the protection was reversed by administration of the NOS inhibitor, N（o））-nitro-l-arginine methyl ester （L-NAME）. Conclusion： These results demonstrate that the eNOS provides cardiac protection after myocardial infarction injury through inhibition of cardiac apoptosis and collagen deposition, and suppression of TGF-β1.

TBC1D15 deficiency protects against doxorubicin cardiotoxicity via inhibiting DNAPKcs cytosolic retention and DNA damage

Clinical application of doxorubicin(DOX)is heavily hindered by DOX cardiotoxicity.Several theories were postulated for DOX cardiotoxicity including DNA damage and DNA damage response(DDR),although the mechanism(s)involved remains to be elucidated.This study evaluated the potential role of TBC domain family member 15(TBC1D15)in DOX cardiotoxicity.Tamoxifen-induced cardiac-specific Tbcldi5 knockout(Tbcldi5^(CKO))or Tbcldi5 knockin(Tbcldi5^(CKI))male mice were challenged with a single dose of DOx prior to cardiac assessment 1 week or 4 weeks following DOX challenge.Adenoviruses encoding TBC1D15 or containing shRNA targeting Tbcld15 were used for Tbcld15 overexpression or knockdown in isolated primary mouse cardiomyocytes.Our results re-vealed that DOX evoked upregulation of TBC1D15 with compromised myocardial function and overt mortality,the effects of which were ameliorated and accentuated by Tbcldi5 deletion and Tbcld15 overexpression,respectively.DOX overtly evoked apoptotic cell death,the effect of which was alleviated and exacerbated by Tbcld15 knockout and overexpression,respectively.Meanwhile,DOX provoked mitochondrial membrane potential collapse,oxidative stress and DNA damage,the effects of which were mitigated and exacerbated by Tbcld15 knockdown and overexpression,respectively.Further scrutiny revealed that TBC1D15 fostered cytosolic accumulation of the cardinal DDR element DNA-dependent protein kinase catalytic subunit(DNA-PKcs).Liquid chromatography-tandem mass spectrometry and coimmunoprecipitation denoted an interaction between TBCID15 and DNA-PKcs at the segment 594-624 of TBC1D15.Moreover,overexpression of TBC1D15 mutant(A594-624,deletion of segment 594-624)failed to elicit accentuation of DOX-induced cytosolic retention of DNA-PKcs,DNA damage and cardiomyocyte apoptosis by TBC1D15 wild type.However,Tbcld15 deletion ameliorated DOXinduced cardiomyocyte contractile anomalies,apoptosis,mitochondrial anomalies,DNA damage and cytosolic DNA-PKcs accumulation,which were canceled off by DNA-PKcs inhibition or ATM activation.Taken together,our findings denoted a pivotal role for TBCID15 in DOX-induced DNA damage,mitochondrial injury,and apoptosis possibly through binding with DNA-PKcs and thus gate-keeping its cytosolic retention,a route to accentuation of cardiac contractile dysfunction in DOX-induced cardiotoxicity.

Isorhapontigenin protects against doxorubicin-induced cardiotoxicity via increasing YAP1 expression

As an effective anticancer drug, the clinical limitation of doxorubicin(Dox) is the time-and dose-dependent cardiotoxicity. Yes-associated protein 1(YAP1) interacts with transcription factor TEA domain 1(TEAD1) and plays an important role in cell proliferation and survival. However, the role of YAP1 in Dox-induced cardiomyopathy has not been reported. In this study, the expression of YAP1 was reduced in clinical human failing hearts with dilated cardiomyopathy and Dox-induced in vivo and in vitro cardiotoxic model. Ectopic expression of Yap1 significantly blocked Dox-induced cardiomyocytes apoptosis in TEAD1 dependent manner. Isorhapontigenin(Isor) is a new derivative of stilbene and responsible for a wide range of biological processes. Here, we found that Isor effectively relieved Doxinduced cardiomyocytes apoptosis in a dose-dependent manner in vitro. Administration with Isor(30 mg/kg/day, intraperitoneally, 3 weeks) significantly protected against Dox-induced cardiotoxicity in mice. Interestingly, Isor increased Dox-caused repression in YAP1 and the expression of its target genes in vivo and in vitro. Knockout or inhibition of Yap1 blocked the protective effects of Isor on Dox-induced cardiotoxicity. In conclusion, YAP1 may be a novel target for Dox-induced cardiotoxicity and Isor might be a new compound to fight against Dox-induced cardiotoxicity by increasing YAP1 expression.