Cardioprotective Potential of Cymbopogon citratus Essential Oil against Isoproterenol-induced Cardiomyocyte Hypertrophy:Possible Involvement of NLRP3 Inflammasome and Oxidative Phosphorylation Complex Subunits

Objective:Cymbopogon citratus(DC.)Stapf is a medicinal and edible herb that is widely used for the treatment of gastric,nervous and hypertensive disorders.In this study,we investigated the cardioprotective effects and mechanisms of the essential oil,the main active ingredient of Cymbopogon citratus,on isoproterenol(ISO)-induced cardiomyocyte hypertrophy.Methods:The compositions of Cymbopogon citratus essential oil(CCEO)were determined by gas chromatography-mass spectrometry.Cardiomyocytes were pretreated with 16.9µg/L CCEO for 1 h followed by 10µmol/L ISO for 24 h.Cardiac hypertrophy-related indicators and NLRP3 inflammasome expression were evaluated.Subsequently,transcriptome sequencing(RNA-seq)and target verification were used to further explore the underlying mechanism.Results:Our results showed that the CCEO mainly included citronellal(45.66%),geraniol(23.32%),and citronellol(10.37%).CCEO inhibited ISO-induced increases in cell surface area and protein content,as well as the upregulation of fetal gene expression.Moreover,CCEO inhibited ISO-induced NLRP3 inflammasome expression,as evidenced by decreased lactate dehydrogenase content and downregulated mRNA levels of NLRP3,ASC,CASP1,GSDMD,and IL-1β,as well as reduced protein levels of NLRP3,ASC,pro-caspase-1,caspase-1(p20),GSDMD-FL,GSDMD-N,and pro-IL-1β.The RNA-seq results showed that CCEO inhibited the increase in the mRNA levels of 26 oxidative phosphorylation complex subunits in ISO-treated cardiomyocytes.Our further experiments confirmed that CCEO suppressed ISO-induced upregulation of mt-Nd1,Sdhd,mt-Cytb,Uqcrq,and mt-Atp6 but had no obvious effects on mt-Col expression.Conclusion:CCEO inhibits ISO-induced cardiomyocyte hypertrophy through the suppression of NLRP3 inflammasome expression and the regulation of several oxidative phosphorylation complex subunits.

L-carvone attenuates myocardial injury and dyslipidemia in rats with isoproterenol-induced cardiac hypertrophy

Objective:To explore the therapeutic efficacy of L-carvone from Mentha spicata L.leaf extracts against isoproterenol-induced cardiac hypertrophy in rats.Methods:Isoproterenol(5 mg/kg)was injected intraperitoneally into rats for one month to induce cardiac hypertrophy.L-carvone(25 and 100 mg/kg)was administered orally to treat cardiac hypertrophy.The cardioprotective activity of L-carvone was evaluated by electrocardiogram,histopathological analysis as well as determination of biochemical parameters and enzymatic markers.Results:L-carvone from Mentha spicata L.at 25 and 100 mg/kg ameliorated isoproterenol-induced cardiac hypertrophy,as evidenced by reduced QRS interval on electrocardiogram,and decreased heart weight and heart index.In addition,both doses of L-carvone markedly lowered the levels of glucose,total protein,low-density lipoprotein cholesterol,aspartate transaminase,alanine transaminase,lactate dehydrogenase,creatine kinase MB,troponin-Ⅰ,N-terminal pro-B type natriuretic peptide and triglycerides while increasing high-density lipoprotein cholesterol and lipase level(P<0.05).Moreover,L-carvone alleviated contraction band necrosis,and reorganized the myofibrils with normal striations and myocytes as well as normal nuclei in cardiac histoarchitecture of rats with isoproterenol-induced cardiac hypertrophy.Conclusions:L-carvone from Mentha spicata L.leaf extract can restore abnormal cardiac function and may be further explored as a therapeutic agent against the deleterious effects of cardiac hypertrophy after further evaluation.

Ascending aorta dilatation reduces the influence of elevated pulse pressure on left ventricular hypertrophy:findings from a Chinese elderly hypertensive population

OBJECTIVE To determine the role of ascending aorta dilatation in the relationship between pulse pressure(PP)and left ventricular(LV)hypertrophy.METHODS A total of 1556 Chinese elderly hypertensive patients were retrospectively studied.Transthoracic echocardiography was used to obtain the aortic and cardiac structure measurements.In addition,brachial blood pressure was measured,and total arterial compliance,systemic vascular resistance,arterial elastance,and end-systolic LV elastance were calculated.The participants were divided into four groups according to the status of ascending aortic diameter and PP.RESULTS LV mass index increased in succession in the four groups,i.e.,the group with the normal aorta and lower PP,with the normal aorta and higher PP,with aortic dilatation and lower PP,and with aortic dilatation and higher PP(Ptrend<0.001).Total arterial compliance−1,arterial elastance,and end-systolic LV elastance were slightly higher in the individuals with normal aorta compared to those with aortic dilatation,regardless of PP being lower or higher(P<0.01).Compared to the group with the normal aorta and lower PP,individuals with aortic dilatation had a significantly increased multivariable adjusted risk of LV hypertrophy,and higher PP further exacerbated this risk[aortic dilatation with lower PP(OR=1.75,95%CI:1.01–3.04)and aortic dilatation with higher PP(OR=3.42,95%CI:2.03–5.77)].In the relation between PP and LV mass index(β=0.095,P<0.001),-41.3%of the total effect was attributable to mediation by ascending aortic diameter(P<0.0001).CONCLUSIONS In Chinese elderly patients with hypertension,ascending aorta dilatation could reduce the influence of elevated PP on LV hypertrophy.

Bicuspid aortic valve with associated aortopathy, significant left ventricular hypertrophy or concomitant hypertrophic cardiomyopathy: A diagnostic and therapeutic challenge

Due to its prevalence of 0.5%to 2%in the general population,with a 75%predominance among men,bicuspid aortic valve is the most common congenital heart defect.It is frequently accompanied by other cardiac congenital anomalies,and clinical presentation can vary significantly,with stenosis being the most common manifestation,often resulting in mild to moderate concentric hypertrophy of the left ventricle.Echocardiography is the primary diagnostic modality utilized for establishing the diagnosis,and it is often the sole diagnostic tool relied upon by clinicians.However,due to the heterogeneous clinical presentation and possible associated anomalies(which are often overlooked in clinical practice),it is necessary to employ various diagnostic methods and persist in finding the accurate diagnosis if multiple inconsistencies exist.By employing this approach,we can effectively manage these patients and provide them with appropriate treatment.Through a clinical case from our practice,we provide an overview of the literature on bicuspid aortic valve with aortophaty and the possible association with hypertrophic cardiomyopathy,diagnostic methods,and treatment options.This review article highlights the critical significance of achieving an accurate diagnosis in patients with bicuspid aortic valve and significant left ventricular hypertrophy.It is crucial to exclude other possible causes of left ventricular outflow tract obstruction,such as sub-or supra-aortic obstructions,and hypertrophic cardiomyopathy.

Effect of matrine and carvedilol on collagen and MMPs activity of hypertrophy myocardium induced by pressure overload

Objective： To explore the effect and mechanism of matrine （Mt.） on myocardial interstitial fibrosis induced by pressure overload. Methods： Pressure overloaded myocardial hypertrophy was produced by banding of aorta abdominalis in 67 male Sprague-Dawley rats weighing （200±15） g. The rats were assigned into one of the following groups： sham-operation control, operation control, operation group treated with matrine （15 mg/（kg·d）） and treated with carvedilol （Car.） （3.6 mg/（kg·d）） group. The rats were given drugs one day after operation. Five weeks after treatment, the left ventricular weight （LVW） was measured and the volume of myocardial cells was detected with Hematoxylin-Eosin （H-E） stain and Masson stain was used to assess the level of fibrosis of the myocardial matrix. Myocardial metalloproteinase activity was quantified with zymography, and survival rate was calculated. Results： Survival rate significantly decreased （P〈0.05）, LVW/BW （body weight）, MMP-2 （matrix metalloproteinase-2） activity （P〈0.05）, size of cardiomyocytes and interstitial fibrosis obviously increased in the operation group compared with sham control group. Mr. and Car. treatment can significantly increase survival rate （P〈0.05）, decrease LVW/BW （P〈0.05） and MMP-2 activity （P〈0.05）, decrease size of cardiomyocytes and interstitial fibrosis compared with operation group. But there was difference compared with sham group. Conclusion： Matrine was shown to be able to prevent cardiac remodelling of bypertrophy cardium induced by pressure overload including myocardial hypertrophy and fibrosis which may be associated with the decrease in MMP-2 activity of heart.

Effects of combination of irbesartan and perindopril on calcineurin expression and sarcoplasmic reticulum Ca^(2+)-ATPase activity in rat cardiac pressure-overload hypertrophy

Aim： To observe effects of angiotensin （Ang） II receptor antagonist （ATI） irbesartan and angiotensin-converting enzyme （ACE） inhibitor perindopril on rat myocardium calcineurin expression and sarcoplasmic reticulum Ca^2＋-ATPase activity in the model of pressure-overload cardiac hypertrophy. Methods： Forty male adult Sprague Dawley rats were divided into 5 groups One group was treated by sham operation; four groups were myocardium hypertrophy cases caused by banding aortic above renal artery. Drugs were given one week after operation. Group 1： sham group, rats （n=8） were gavaged with normal saline 2 ml/（kg·d） （ig）; Group 2： control group, rats （n=8） were treated with normal saline 2 ml/（kg·d） （ig）; Group 3： rats （n=8） were given perindopril 2 mg/（kg·d） （ig）; Group 4： rats （n=8） were treated with irbesartan 20 mg/（kg·d） （ig）; Group 5： rats （n=8） were given irbesartan 20 mg/（kg·d） plus perindopril 2 mg/（kg·d） （ig）. Morphometric determination, calcineurin expression and sarcoplasmic reticulum Ca^2＋-ATPase activity were done at the end of 6 week of drug intervention. Expression of calcineurin in myocardium was detected by immunohistochemistry. Results： Left ventricular mass index （LVMI）, transverse diameter of myocardial cell （TDM）, calcineurin activity were remarkably decreased after drug intervention and this decrease was most remarkable in the combination drug therapy group. Sarcoplasmic reticulum Ca^2＋-ATPase activity was increased after drug intervention, especially in the combined drug therapy group. Calcineurin expression in myocardium was remarkably decreased after drug intervention. LVMI was positively correlated with TDM and calcineurin, negatively correlated with sarcoplasmic reticulum Ca^2＋-ATPase. Conclusion： These data suggest that irbesartan and perindopril inhibit cardiac hypertrophy through the increased activity of sarcoplasmic reticulum Ca^2＋-ATPase and decreased expression of calcineurin. Their combination had better effects on regressing of ventricular hypertrophy.

DMP1 prevents osteocyte alterations,FGF23 elevation and left ventricular hypertrophy in mice with chronic kidney disease

During chronic kidney disease (CKD),alterations in bone and mineral metabolism include increased production of the hormone fibroblast growth factor 23 (FGF23) that may contribute to cardiovascular mortality.The osteocyte protein dentin matrix protein 1 (DMP1) reduces FGF23 and enhances bone mineralization,but its effects in CKD are unknown.We tested the hypothesis that DMP1 supplementation in CKD would improve bone health,prevent FGF23 elevations and minimize consequent adverse cardiovascular outcomes.We investigated DMP1 regulation and effects in wild-type (WT) mice and the Col4a3^-/- mouse model of CKD.Col4a3^-/- mice demonstrated impaired kidney function,reduced bone DMP1 expression,reduced bone mass,altered osteocyte morphology and connectivity,increased osteocyte apoptosis,increased serum FGF23,hyperphosphatemia,left ventricular hypertrophy (LVH),and reduced survival.Genetic or pharmacological supplementation of DMP1 in Col4a3^-/- mice prevented osteocyte apoptosis,preserved osteocyte networks,corrected bone mass,partially lowered FGF23 levels by attenuating NFAT-induced FGF23 transcription,and further increased serum phosphate.Despite impaired kidney function and worsened hyperphosphatemia,DMP1 prevented development of LVH and improved Col4a3^-/- survival.Our data suggest that CKD reduces DMP1 expression,whereas its restoration represents a potential therapeutic approach to lower FGF23 and improve bone and cardiac health in CKD.

Changes of c-fos and c-jun mRNA Expression in Angiotensin Ⅱ-induced Cardiomyocyte Hypertrophy and Effects of Sodium Tanshinone ⅡA Sulfonate

The changes of proto-oncogene c-fos and c-jun mRNA expression in angiotensin Ⅱ （AngⅡ）-induced hypertrophy and effects of sodium tanshinone ⅡA sulfonate （STS） in the primary culture of neonatal rat cardiomyocytes were investigated. Twelve neonatal clean grade Wistar rats were selected. The cardiomyocytes were isolated, cultured and divided according to different treatments in the medium. The cardiomyocyte size was determined by phase contrast microscope, and the rate of protein synthesis was measured by [3H]-Leucine incorporation. The c-fos and c-jun mRNA expression in cardiomyocytes was detected by reverse transcription polymerase chain reaction （RT-PCR）. It was found after cardiomyocytes were treated with AngⅡ for 30 min, the c-fos and c-jun mRNA expression in cardiomyocytes was increased significantly （P〈0.01）. After treatment with AngⅡ for 24 h, the rate of protein synthesis in AngⅡ group was significantly increased as compared with control group （P〈0.01）. After treatment with AngⅡ for 7 days, the size of cardiomyocytes in AngⅡ group was increased obviously as compared with control group （P〈0.05）. After pretreatment with STS or Valsartan before AngⅡ treatment, both of them could inhibit the above effects of AngⅡ （P〈0.05 or P〈0.01）. It was suggested that STS could ameliorate AngⅡ-induced cardiomyocyte hy- pertrophy by inhibiting c-fos and c-jun mRNA expression and reducing protein synthesis rate of cardiomyocytes.

Notch signaling controls chondrocyte hypertrophy via indirect regulation of Sox9

RBPjk-dependent Notch signaling regulates both the onset of chondrocyte hypertrophy and the progression to terminal chondrocyte maturation during endochondral ossification. It has been suggested that Notch signaling can regulate Sox9 transcription, although how this occurs at the molecular level in chondrocytes and whether this transcriptional regulation mediates Notch control of chondrocyte hypertrophy and cartilage development is unknown or controversial. Here we have provided conclusive genetic evidence linking RBPjk-dependent Notch signaling to the regulation of Sox9 expression and chondrocyte hypertrophy by examining tissuespecific Rbpjk mutant（Prx1Cre;Rbpjkf/f）, Rbpjk mutant/Sox9 haploinsufficient（Prx1Cre;Rbpjkf/f;Sox9f/1）,and control embryos for alterations in SOX9 expression and chondrocyte hypertrophy during cartilage development. These studies demonstrate that Notch signaling regulates the onset of chondrocyte maturation in a SOX9-dependent manner, while Notch-mediated regulation of terminal chondrocyte maturation likely functions independently of SOX9. Furthermore, our in vitro molecular analyses of the Sox9 promoter and Notch-mediated regulation of Sox9 gene expression in chondrogenic cells identified the ability of Notch to induce Sox9 expression directly in the acute setting, but suppresses Sox9 transcription with prolonged Notch signaling that requires protein synthesis of secondary effectors.

Expression of Wnt and NCX1 and its correlation with cardiomyocyte apoptosis in mouse with myocardial hypertrophy

Objective:To study the correlation between expression of Wnt and NCXl and cardiomyocyte apoptosis in mouse with myocardial hypertrophy.Methods:C57B/16 male mice were given the subcutaneous injection of 1 mg/kg isoprenaline to build the myocardial hypertrophy model.After 14 d of model building,mice were executed by cervical vertebra luxation.The ratio of heart weight/body weight(HW/BW) and heart weight/tibia length(HW/TL) was observed and proved using HE staining mat detected the size of eaidiomyocytes.40 male C57B/16 mice were randomly divided into the sham group(normal saline) and model group(isoprenaline),with 20 mice in each group.The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling was applied to detect the cardiomyocyte apoptosis;while Western blot and immunohistochemistry were employed to detect the expression of Wnt and NCX1.Meanwhile,the correlation between these two proteins and cardiomyocyte apoptosis was explored.Results:Compared with the sham group,the ratio of HW/BW and HW/TL was increased in the model group,as well as the bigger and hypertrophied cardiomyocytes,decreased number and increased apoptosis of eaidiomyocytes,and increased positive expression of Wnt3 a,WntSa and NCXl in the cardiac muscle tissue.Besides,there was positive correlation between the expression of Wnt and NCXl and the cardiomyocyte apoptosis.Conclusions:The expression of Wnt3 a,Wnt5a and NCXl in mouse with myocardial hypertrophy is increased and positively correlated with the cardiomyocyte apoptosis.

Left ventricular hypertrophy amplifies the QT,and Tp-e intervals and the Tp-e/QT ratio of left chest ECG

Objective： To evaluate the changes in Tp-e interval （an interval from the peak to the end of the T wave）, QT interval and Tp-e/QT ratio of the body surface ECG in patients with left ventricular hypertrophy （LVH）. Methods： The Tp-e interval and QT interval were measured on body surface ECGs in 42 patients without either hypertension or LVH （control group）, 41 patients having hypertension but not LVH （non-LVH group）, and 38 patients with both hypertension and LVH （LVH group）. Results： The mean corrected QT （QTc） interval, and mean corrected Tp-e[T（p-e）c] interval were significantly longer in the LVH group （0.430±0.021s vs. 0.409±0.019s, p 〈 0.01; 0.098±0.013s vs. 0.088±0.011s, respectively） than those in the control group. The Tp-e/QT ratio was also amplified in LVH group （0.232± 0.028 vs.0.218± 0.027） （p 〈 0.05）. Conclusion： LVH increased the QT interval, Tp-e interval and Tp-e/QT ratio of the body surface ECG.

Association of asymptomatic otitis media with effusion in patients with adenoid hypertrophy

Objective: Clinical symptoms of otitis media with effusion are rarely brought forward to the guardians of young children who the disease is most prevalent in. This often leads to poor scholastic performances and difficult social interactions. The objective of this study was to identify asymptomatic cases of otitis media with effusion present in individuals with adenoid hypertrophy. Material and Methods: In a cross sectional study advocated in Justice K.S.Hegde Hospital, Karnataka India we evaluated one hundred patients above the age of three from August 2016 to December 2017. Candidates who presented with an adenoid nasopharyngeal ratio of more than 0.5 were selected for the study. Individuals who complained of otological symptoms were not considered for the study. Patients cleared of other pathological otological conditions were underwent audiological evaluation with pure tone audiometry and tympanometry for evaluating the middle ear status and hearing loss. Results: The study showed a total of 36% of patients evaluated presented with asymptomatic otitis media with effusion. In candidates who presented with a bilateral B tympanogram, 40% had significant conductive hearing loss of more than 25dB. Conclusion: An objective test such as impedance audiometry in all patients with adenoid hypertrophy would aid in the diagnosis of fluid in the middle ear, so that timely intervention can be done and possible complications be averted.

Effect of Zhenwu Tang Granule on pressure-overloaded left ventricular myocardial hypertrophy in rats

BACKGROUND： In the perspective of traditional Chinese medicine, few studies have focused on the compound preparations though there are many investigations. The present study was undertaken to investigate the effect of Zhenwu Tang Granule on chronic pressure-overloaded left ventricular hypertrophy in rats.METHODS： The study was performed at the laboratory of Guangzhou Institute of Respiratory Disease. Male SD rats were divided randomly into 3 groups： sham operation group （n=8）, operation group （n=15） and traditional Chinese medicine （TCM） group （n=15）.The model of myocardial hypertrophy was made by gradually constricting the abdominal aorta. Sixteen weeks later, cardiac ultrasonography was performed in all groups in order to ascertain post-operational left ventricular （LV） hypertrophy. And Zhenwu Tang Granule was added at a dose of 12 g/kg in the mixed feedstuff for 8 weeks in the TCM group. In the 24th week, weight, structure as well as function of the heart in each group were measured by high-frequency ultrasonography, and Masson＇s staining was performed on the cardiac muscles. Meanwhile, total collagen volume fraction （CVF-T） and non-coronary vessel collagen volume fraction （CVF-NV） were analyzed.RESULTS： There was an increase in the weight of the heart in the operation group, with the left ventricule dominated （P〈0.05）. The heart was enlarged, with diastolic interventricular septal distance （IVSd） and left ventricular posterior wall distance （LVPWd） dominated （P〈0.01）.There was a significant decrease in the cardiac function （P〈0.05）. The weight （P〈0.01） and volume of the heart decreased in the TCM group compared with the operation group, with IVSd and systolic left ventricular posterior wall dominated （P〈0.01）. And the cardiac function was improved （P〈0.05）. Significant interstitial and collagen hyperplasia was shown in the operation group based on pathological analysis, and various improvements were proved in the TCM group, i.e. there was a significant decrease in CVF-T and CVF-NV （P〈0.01） compared with the operation group; but no difference （P〉0.05） was found when compared with the pseudo-operation group.CONCLUSION： Zhenwu Tang Granule could reduce the weight and volume of the heart, improve the cardiac function, inhibit hyperplasia of collagen, and reverse myocardial hypertrophy in rats with pressure-overloaded left ventricular hypertrophy.

Portal vein embolization for induction of selective hepatic hypertrophy prior to major hepatectomy: rationale,techniques, outcomes and future directions

The ability to modulate the future liver remnant(FLR) is a key component of modern oncologic hepatobiliary surgery practice and has extended surgical candidacy for patients who may have been previously thought unable to survive liver resection. Multiple techniques have been developed to augment the FLR including portal vein embolization(PVE), associating liver partition and portal vein ligation(ALPPS), and the recently reported transhepatic liver venous deprivation(LVD). PVE is a well-established means to improve the safety of liver resection by redirecting blood flow to the FLR in an effort to selectively hypertrophy and ultimately improve functional reserve of the FLR. This article discusses the current practice of PVE with focus on summarizing the large number of published reports from which outcomes based practices have been developed. Both technical aspects of PVE including volumetry, approaches, and embolization agents; and clinical aspects of PVE including data supporting indications, and its role in conjunction with chemotherapy and transarterial embolization will be highlighted. PVE remains an important aspect of oncologic care; in large part due to the substantial foundation of information available demonstrating its clear clinical benefit for hepatic resection candidates with small anticipated FLRs.

Nardosinone Protects H9c2 Cardiac Cells from Angiotensin Ⅱ-induced Hypertrophy

Pathological cardiac hypertrophy induced by angiotensin Ⅱ （Ang Ⅱ ） can subsequently give rise to heart failure, a leading cause of mortality. Nardosinone is a pharmacologically active compound extracted from the roots ofNardostachys chinensis, a well-known traditional Chinese medicine. In order to investigate the effects of nardosinone on Ang Ⅱ-induced cardiac cell hypertrophy and the related mechanisms, the myoblast cell line H9c2, derived from embryonic rat heart, was treated with nardosi- none （25, 50, 100, and 200μmol/L） or Ang Ⅱ （1 μmol/L）. Then cell surface area and mRNA expression of classical markers of hypertrophy were detected. The related protein levels in PI3K/Akt/mTOR and MEK/ERK signaling pathways were examined by Western blotting. It was found that pretreatment with nardosinone could significantly inhibit the enlargement of cell surface area induced by Ang Ⅱ. The mRNA expression of ANP, BNP and 13-MHC was obviously elevated in Ang Ⅱ-treated H9c2 cells, which could be effectively blocked by nardosinone at the concentration of 100μmol/L. Further study revealed that the protective effects of nardosinone might be mediated by repressing the phosphorylation of related proteins in PI3K/Akt and MEK/ERK signaling pathways. It was suggested that the inhibitory effect of nardosinone on Ang Ⅱ-induced hypertrophy in H9c2 cells might be mediated by targeting PI3K/Akt and MEK/ERK signaling pathways.

Magnolol attenuates right ventricular hypertrophy and fibrosis in hypoxia-induced pulmonary arterial hypertensive rats through inhibition of the JAK2/STAT3 signaling pathway

OBJECTIVE Right ventricular(RV)remodeling is one of the essential pathological features in pulmonary arterial hypertension(PAH).RV hypertrophy or fibrosis are the leading causes of RV remodeling.Magnolol is a compound isolated from Magnolia officinalis.It possesses multiple pharmacological activities,such as anti-oxidation and anti-inflammation.This study aims to evaluate the effects and underlying mechanisms of magnolol on RV remodeling in hypoxia-induced PAH.METHODS①Male SD rats(220 g)were randomly divided into 5 groups(n=10):the normoxia group,the hypoxia group,the hypoxia plus Magnolol(10 and 20 mg·kg^(-1)·d-1)group,and the vehicle group.Rats in the normoxia group were kept in a normoxia environment for 4 weeks,while rats in the hypoxia group were kept in a hypoxic chamber(10%O2).The rats in the hypoxia plus magnolol groups were administered with magnolol at 10 or 20 mg·kg^(-1)(ip)once a day for 4 weeks.At the end of 4 weeks,the heart function was assessed by Doppler echocardiography,and then the rats were anesthetized with sodium pentobarbital(30 mg·kg^(-1),ip).The RVSP was measured by the right heart catheterization method.The heart tissues were collected and dissected to calculate the index of RV remodeling(RV/LV+IVS,RV/tibial length,or RV/body weight).Part of the RV samples was fixed with 4%paraformaldehyde for morphological analysis,while other samples were frozen at-80℃for molecular studies(measurements of ANP,BNP,α-SMA,and collagenⅠ/ⅢmRNA expression as well as p-JAK2/JAK2 and p-STAT3/STAT3 protein levels).②To evaluate the effect of magnolol on hypoxia-induced myocardial hypertrophy and fibrosis,H9c2 or cardiac fibroblasts were divided into 7 groups:the control group,cells were cultured under normal conditions;the hypoxia group,cells were cultured under hypoxic condition(3%O2);the hypoxia plus magnolol 10 mg·kg^(-1) group,magnolol10μmol·L^(-1) was added to the culture medium before the hypoxia treatment;the hypoxia plus magnolol 30 mg·kg^(-1) group,magnolol 20μmol·L^(-1) was added to the culture medium before the hypoxia treatment;the hypoxia plus TG-101348 group,TG-101348(a specific inhibitor of JAK2)1μmol·L^(-1) was added to the culture medium before the hypoxia treatment;the hypoxia plus JSI-124 group,JSI-124(a specific inhibitor of JAK2)1μmol·L^(-1) was added to the culture medium before the hypoxia treatment;and the hypoxia plus vehicle group,an equal volume of vehicle(DMSO)was added to the culture medium before the hypoxia treatment.At the end of the experiments,the cells were collected for morphological and molecular analysis.RESULTS In vivo,male Sprang-Daley rats were exposed to 10%O2 for 4 weeks to establish an RV remodeling model,which showed hypertrophic and fibrotic features(increases of RV remodeling index,cellular size,hypertrophic and fibrotic marker expression),accompanied by an elevation in phosphorylation levels of JAK2 and STAT3;these changes were attenuated by treating rats with magnolol.In vitro,the cultured H9c2 cells or cardiac fibroblasts were exposed to 3%O2 for 48 h to induce hypertrophy or fibrosis,which showed hypertrophic(increases in cellular size as well as the expression of ANP and BNP)or fibrotic features(increases in the expression of collagenⅠ,collagenⅢandα-SMA).Administration of magnolol and TG-101348 or JSI-124 (JAK2 selective inhibitors) could prevent the process of myocardial hypertrophy and fibrosis, accompanied by the decrease in the phosphorylation level of JAK2 and STAT3. CONCLUSION Magnolol can attenuate RV hypertrophy and fibrosis in hypoxia-induced PAH rats through a mechanism involving inhibition of the JAK2/STAT3 signaling pathway.

Total Glycosides of Ranunculus Japonius Prevent Hypertrophy in Cardiomyocytes via Alleviating Chronic Ca^(2+) Overload

Objective To evaluate the in vitro anti-hypertrophic effect of total Glycosides of Ranunculus Japonius （TGRJ）. Methods Neonatal rat cardiomyocytes were cultured and hypertrophy was induced by adminis- trating isoproterenol （ISO, 10 gmol/L） or angiotensin Ⅱ （AngⅡ, 1 gmol/L） for 48 hours. In the treatment groups, cells were pretreated with TGRJ （0.3 g/L） for 30 minutes prior to hypertrophic stimuli. The anti-hypertrophic effects of TGRJ were examined by measuring cell size, total protein content, and protein synthesis. Intracellular free Ca2＋ concentration （[Ca2＋]i） was evaluated using fluorescence dye Fura-2/AM. Sacroplasmic/endoplasmic reticulum Ca2＋ ATPase 2a （SERCA2a）, atrial natriuretic peptide （ANP）, B-type natriuretic peptide （BNP）, and beta-myosin heavy chain （β-MHC） protein expression levels were measured by Western blotting. SERCA2a activity was assayed by p-nitrophenal phosphate disodium salt hexahydrate method. Results Increased cell size, total protein content, and protein synthesis following ISO or Ang II stimulation were significantly inhibited by pretreatment with TGRJ （all P〈0.05）. This anti-hypertrophic effect of TGRJ was confirmed by its suppressing effect on elevated expression of the three hypertrophic related genetic markers, ANP, BNP, and ^-MHC. In addition, TGRJ inhibited ISO or Ang Ⅱ induced up-regulation of [Ca2＋] under chronic but not acute conditions. And ISO or Ang Ⅱ induced down-regulation of SERCA2a expression and activity was also effectively rectified byTGRJ pretreatment. Conclusions The results of present study suggested that TGRJ could prevent ISO or Ang Ⅱ induced cardiac hypertrophy through improving chronic [Ca2＋]i disorder, might via normalizing SERCA2a expression and activity.

Hyperplasia vs hypertrophy in tissue regeneration after extensive liver resection

To address to what extent hypertrophy and hyperplasia contribute to liver mass restoration after major tissue loss.METHODSThe ability of the liver to regenerate is remarkable on both clinical and biological grounds. Basic mechanisms underlying this process have been intensively investigated. However, it is still debated to what extent hypertrophy and hyperplasia contribute to liver mass restoration after major tissue loss. We addressed this issue using a genetically tagged system. We were able to follow the fate of single transplanted hepatocytes during the regenerative response elicited by 2/3 partial surgical hepatectomy (PH) in rats. Clusters of transplanted cells were 3D reconstructed and their size distribution was evaluated over time after PH.RESULTSLiver size and liver DNA content were largely recovered 10 d post-PH, as expected (e.g., total DNA/liver/100 g b.w. was 6.37 ± 0.21 before PH and returned to 6.10 ± 0.36 10 d after PH). Data indicated that about 2/3 of the original residual hepatocytes entered S-phase in response to PH. Analysis of cluster size distribution at 24, 48, 96 h and 10 d after PH revealed that about half of the remnant hepatocytes completed at least 2 cell cycles. Average size of hepatocytes increased at 24 h (248.50 μm2 ± 7.82 μm2, P = 0.0015), but returned to control values throughout the regenerative process (up to 10 d post-PH, 197.9 μm2 ± 6.44 μm2, P = 0.11). A sizeable fraction of the remnant hepatocyte population does not participate actively in tissue mass restoration.CONCLUSIONHyperplasia stands as the major mechanism contributing to liver mass restoration after PH, with hypertrophy playing a transient role in the process.

Decorin Induces Cardiac Hypertrophy by Regulating the CaMKⅡ/MEF-2 Signaling Pathway In Vivo

Objective:Cardiac hypertrophy is an adaptive reaction of the heart against cardiac overloading,but continuous cardiac hypertrophy can lead to cardiac remodeling and heart failure.Cardiac hypertrophy is mostly considered reversible,and recent studies have indicated that decorin not only prevents cardiac fibrosis associated with hypertension,but also achieves therapeutic effects by blocking fibrosis-related signaling pathways.However,the mechanism of action of decorin remains unknown and unconfirmed.Methods:We determined the degree of myocardial hypertrophy by measuring the ratios of the heart weight/body weight and left ventricular weight/body weight,histological analysis and immunohistochemistry.Western blotting was performed to detect the expression levels of CaMKⅡ,p-CaMKⅡ and MEF-2 in the heart.Results:Our results confirmed that decorin can regulate the CaMKⅡ/MEF-2 signaling pathway,with inhibition thereof being similar to that of decorin in reducing cardiac hypertrophy.Conclusion:Taken together,the results of the present study showed that decorin induced cardiac hypertrophy by regulating the CaMKⅡ/MEF-2 signaling pathway in vivo,revealing a new therapeutic approach for the prevention of cardiac hypertrophy.

Contra-lateral liver lobe hypertrophy after unilobar Y90 radioembolization:An alternative to portal vein embolization?

Liver resection(LR) with negative margins confers survival advantage in many patients with hepatic malignancies.However,an adequate future liver remnant(FLR) is imperative for safe LR.Presently,in patients with an inadequate FLR; the 2 most established clinical techniques performed to induce liver hypertrophy are portal vein embolization(PVE) and portal vein ligation.More recently,it has been observed that patients who undergo treatment via Y90 radioembolization experience hypertrophy of the contra-lateral untreated liver lobe.Based on these observations,several investigators have proposed the potential use of this modality as an alternative technique for increasing the FLR prior to liver resection.Y90 radioembolization induces hypertrophy at a slower rate than PVE but has the added advantage of concomitant local disease control and tumour downstaging.