Loeffler's Endocarditis- A cause of endomyocardial fibrosis in a patient of juvenile idiopathic arthritis: A Case Report.

Endomyocardial fibrosis secondary to hyper-eosinophilic syndrome also known as Loeffler's Endocarditis is a rare cause of restrictive cardiomyopathy. If left untreated, it carries a very high morbidity and mortality rate. The case of a 20 years old girl, a known case of polyarticular juvenile idiopathic arthritis since the age of 13 years was reported at Federal Government Polyclinic Hospital, Islamabad on 14th May 2022. She presented with an acute history of shortness of breath and cough for two weeks. Her initial echocardiogram showed suspicion of Loeffler's Endocarditis, which is attributed to be an adverse effect of etanercept- a tumour necrosis factor (TNF) inhibitor, which she had been prescribed for her arthritis. The patient is currently being managed with high doses of steroids, therapeutic anticoagulation with rivaroxaban, carvedilol for tachycardia and mycophenolate mofetil as an immunosuppressant.

Exploration of the Mechanism of Tripterygium Wilfordii in the Treatment of Myocardial Fibrosis Based on Network Pharmacology and Molecular Docking.

BACKGROUND: A network pharmacology study on the biological action of Tripterygium wilfordii on myocardial fibrosis (MF). METHODS: The effective components and potential targets of tripterygium wilfordii were screened from the TCMSP database to develop a combination target network. A protein-protein interaction network was constructed by analyzing the interaction between tripterygium wilfordii and MF; then, the Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed. Furthermore, molecular docking was utilized to verify the network analysis results. RESULTS: It was predicted that MF has 29 components contributing to its effectiveness and 87 potential targets. It is predicted that Tripterygium wilfordii has 29 active components and 87 potential targets for the treatment of MF. The principal active components of tripterygium wilfordii include kaempferol, ß-sitosterol, triptolide, and Nobiletin. Signaling pathways: AGE-RAGE, PI3K-Akt, and MAPK may be involved in the mechanism of its action.7 Seven key targets (TNF, STAT3, AKT1, TP53, VEGFA, CASP3, STAT1) are possibly involved in treating MF by tripterygium wilfordii. CONCLUSION: This study shows the complex network relationship between multiple components, targets, and pathways of Tripterygium wilfordii in treating MF.

Ocupação apical por endomiocardiofibrose associada a trombo diagnosticada com ecocardiografia de contraste e resolvida com tratamento clínico / Apical occupation by endomyocardiofibrosis associated with thrombus diagnosed with contrast echocardiography and resolved with clinical treatment

A endomiocardiofibrose é uma doença negligenciada e predominante em países subdesenvolvidos. Apesar de sua frequência, ainda é considerada rara. Assim, a doença é marcada pelos seguintes achados: distorção arquitetural, alterações no enchimento ventricular e alterações da mobilidade segmentar. Ela afetando não só a dinâmica diastólica e sistólica, como também as funções das válvulas cardíacas. Em uma condição mais avançada da doença, pode haver formação de trombos apicais. Neste relato de caso, revisitamos a endomiocardiofibrose, apresentando um caso desafiador de paciente do sexo feminino de 52 anos, com clínica de insuficiência cardíaca classe funcional IV da New York Heart Association. A eletrocardiografia de repouso revelou ritmo sinusal com sobrecarga do ventrículo esquerdo com vetores de alta voltagem, infradesnivelamento retificado do segmento ST e onda T negativa em região anterolateral, podendo ser compatível com padrão de strain. Já na avaliação de imagens ecocardiográficas, revelou dilatação acentuada do átrio esquerdo, com ventrículos sem dilatações e imagem de ocupação apical hiperrefringente no interior do ventrículo esquerdo, sugerindo grande trombo séssil sobreposto à capa fibrosa endocárdica. Embora a conduta cirúrgica seja a mais apoiada em literatura em tais situações, a paciente aqui apresentada recebeu tratamento com anticoagulação oral por 1 mês e 24 dias. Ela evoluiu clinicamente bem, com melhora da classe funcional da New York Heart Association e, em ecocardiografia realizada 2 meses após o início da anticoagulação oral, houve demonstração da regressão da imagem de trombo apical, apoiada com a técnica de contraste endocavitário.(AU)

Endomyocardial fibrosis (EMF) is a neglected but prevalent disease in underdeveloped countries. Despite its frequency, it is still considered a rare disease. It is marked by the following findings: architectural distortion, ventricular filling changes, and segmental mobility changes affecting not only diastolic and systolic dynamics but also heart valve function. Apical thrombi can be formed in more advanced disease. In this case report, we revisit EMF and present the challenging case of a 52-year-old woman with New York Heart Association (NYHA) functional classification (FC) IV heart failure. Resting electrocardiography revealed sinus rhythm with left ventricular (LV) overload, high voltage vectors, rectified ST-segment depression, and a negative T-wave in the anterolateral region compatible with the strain pattern. The evaluation of echocardiographic images showed marked left atrial dilation, no ventricular dilatation, and hyper-refringent apical occupation within the LV suggestive of a large sessile thrombus superimposed on the endocardial fibrous layer. Although surgery is the most supported approach in the literature in such situations, this patient was treated with oral anticoagulants (OAC) for 1 month and 24 days. The patient progressed well with an improved NYHA FC. Endocavitary contrast echocardiography performed 2 months after OAC initiation showed regression of the apical thrombus image. (AU)

Cardiac Fibrosis and Fibroblasts.

Cardiac fibrosis is the excess deposition of extracellular matrix (ECM), such as collagen. Myofibroblasts are major players in the production of collagen, and are differentiated primarily from resident fibroblasts. Collagen can compensate for the dead cells produced by injury. The appropriate production of collagen is beneficial for preserving the structural integrity of the heart, and protects the heart from cardiac rupture. However, excessive deposition of collagen causes cardiac dysfunction. Recent studies have demonstrated that myofibroblasts can change their phenotypes. In addition, myofibroblasts are found to have functions other than ECM production. Myofibroblasts have macrophage-like functions, in which they engulf dead cells and secrete anti-inflammatory cytokines. Research into fibroblasts has been delayed due to the lack of selective markers for the identification of fibroblasts. In recent years, it has become possible to genetically label fibroblasts and perform sequencing at single-cell levels. Based on new technologies, the origins of fibroblasts and myofibroblasts, time-dependent changes in fibroblast states after injury, and fibroblast heterogeneity have been demonstrated. In this paper, recent advances in fibroblast and myofibroblast research are reviewed.

Peptide Szeto­Schiller 31 ameliorates doxorubicin­induced cardiotoxicity by inhibiting the activation of the p38 MAPK signaling pathway.

Oxidative stress serves a key role in doxorubicin (DOX)­induced cardiotoxicity. The peptide Szeto­Schiller (SS)31 is an efficacious antioxidant with the capacity to reduce mitochondrial reactive oxygen species (ROS) levels and scavenge free radicals. Although SS31 is involved in the pathophysiological process of various cardiovascular diseases, the role of SS31 in DOX­induced cardiotoxicity remains unclear. To explore the effects of SS31 in DOX­induced cardiotoxicity, the present study first constructed DOX­induced cardiotoxicity models, in which H9c2 cells were incubated with 1 µM DOX for 24 h and C57BL/6 mice were administered DOX (20 mg/kg cumulative dose). The results of various assays in these models demonstrated that SS31 exhibited a cardioprotective effect in vitro and in vivo by attenuating the level of ROS, stabilizing the mitochondrial membrane potential and ameliorating myocardial apoptosis as well as fibrosis following treatment with DOX. Mechanistically, the results of the present study revealed that the p38 MAPK signaling pathway was inhibited by SS31 in DOX­treated H9c2 cells, which was associated with the cardioprotective function of SS31. In addition, P79350, a selective agonist of p38 MAPK, reversed the protective effects of SS31. Taken together, these results demonstrated the effects of SS31 on ameliorating DOX­induced cardiotoxicity and indicated its potential as a drug for the treatment of DOX­induced cardiotoxicity.

Effects of progranulin on the pathological conditions in experimental myocardial infarction model.

Progranulin is a secreted growth factor associated with multiple physiological functions in ischemic pathophysiology. However, it is still not fully understood how progranulin is involved in ischemic lesion and cardiac remodeling after myocardial infarction (MI). In this study, we investigated the effects of progranulin on myocardial ischemia and reperfusion injury. We investigated progranulin expression using Western blotting and immunostaining after permanent left coronary artery (LCA) occlusion in mice. Infarct size and the number of infiltrating neutrophils were measured 24 h after permanent LCA occlusion. Recombinant mouse progranulin was administered before LCA occlusion. In addition, we evaluated cardiac function using cardiac catheterization and echocardiography, and fibrosis size by Masson's trichrome staining after myocardial ischemia/reperfusion in rabbits. Recombinant human progranulin was administered immediately after induction of reperfusion. Progranulin expression increased in the myocardial ischemic area 1, 3, and 5 days after permanent LCA occlusion in mice. The administration of recombinant mouse progranulin significantly attenuated infarct size and infiltrating neutrophils 24 h after permanent LCA occlusion in mice. We also found that administration of recombinant human progranulin ameliorated the deterioration of cardiac dysfunction and fibrosis after myocardial ischemia/reperfusion in rabbits. These findings suggest that progranulin may protect myocardial ischemia/reperfusion injury.

Effect of Posaconazole in an in vitro model of cardiac fibrosis induced by Trypanosoma cruzi.

Posaconazole (POS) is an inhibitor of ergosterol biosynthesis in clinical use for treating invasive fungal infections. POS has potent and selective anti-Trypanosoma cruzi activity and has been evaluated as a possible treatment for Chagas disease. Microtissues are a 3D culture system that has been shown to reproduce better tissue architecture and functionality than cell cultures in monolayer (2D). It has been used to evaluate chemotropic response as in vitro disease models. We previously developed an in vitro model that reproduces aspects of cardiac fibrosis observed in Chagas cardiomyopathy, using microtissues formed by primary cardiac cells infected by the T. cruzi, here called T. cruzi fibrotic cardiac microtissue (TCFCM). We also showed that the treatment of TCFCM with a TGF-ß pathway inhibitor reduces fibrosis. Here, we aimed to evaluate the effect of POS in TCFCM, observing parasite load and molecules involved in fibrosis. To choose the concentration of POS to be used in TCFCM we first performed experiments in a monolayer of primary cardiac cell cultures and, based on the results, TCFCM was treated with 5 nM of POS for 96 h, starting at 144 h post-infection. Our previous studies showed that at this time the TCFCM had established fibrosis, resulting from T. cruzi infection. Treatment with POS of TCFCM reduced 50 % of parasite load as observed by real-time PCR and reduced markedly the fibrosis as observed by western blot and immunofluorescence, associated with a strong reduction in the expression of fibronectin and laminin (45 % and 54 %, respectively). POS treatment also changed the expression of proteins involved in the regulation of extracellular matrix proteins (TGF-ß and TIMP-4, increased by 50 % and decreased by 58 %, respectively) in TCFCM. In conclusion, POS presented a potent trypanocidal effect both in 2D and in TCFCM, and the reduction of the parasite load was associated with a reduction of fibrosis in the absence of external immunological effectors.

Impact of liraglutide on microcirculation in experimental diabetic cardiomyopathy.

Liraglutide is a new therapy used in diabetes and its effect on diabetic complications particularly cardiovascular ones is still under investigated. In our research, we tried to study the effect of liraglutide on experimental diabetic cardiomyopathy (DCM) induced by streptozotocin. We found that liraglutide nearly preserved normal myocardiac structure and significantly protected against myocardiac inflammation and fibrosis that was found in DCM group, p < 0.05. It also increased the density of coronary arteriolar vasculature markedly indicated by significant increase in α SMA (p < 0.05) compared to both DCM and non-diabetic (ND) groups. Moreover, liraglutide decreased TNFα and increased VEGF proteins expression (P < 0.05) compared to DCM group. Conclusion, liraglutide may have a very important role in protecting against experimentally induced diabetic cardiomyopathy by preventing the degenerative changes in the cardiomyocytes and the associated fibrosis, inflammation and decreased vasculature at structural and molecular levels.

The use of aliskiren as an antifibrotic drug in experimental models: A systematic review.

Aliskiren is an oral antihypertensive medication that acts by directly inhibiting renin. High levels of circulating renin and prorenin activate the pathological signaling pathway of fibrosis. This drug also reduces oxidative stress. Thus, the aim of this systematic review is to analyze experimental studies that show the actions of aliskiren on fibrosis. PubMed and LILACS databases were consulted using the keywords aliskiren and fibrosis within the period between 2005 and 2017. Fifty-three articles were analyzed. In the heart, aliskiren attenuated remodeling, hypertrophy, inflammatory cytokines, collagen deposition, and oxidative stress. In the kidneys, there was a reduction in interstitial fibrosis, the infiltration of inflammatory cells, apoptosis, proteinuria, and in the recruitment of macrophages. In diabetic models, an improvement in the albumin/creatinine relationship and in the insulin pathway in skeletal muscles was observed; aliskiren was beneficial to pancreatic function and glucose tolerance. In the liver, aliskiren reduced fibrosis, steatosis, inflammatory cytokines, and collagen deposition. In the lung and peritoneal tissues, there was a reduction in fibrosis. Many studies have reported on the beneficial effects of aliskiren on endothelial function and arterial rigidity. A reduction in fibrosis in different organs is cited by many authors, which complies with the results found in this review. However, studies diverge on the use of the drug in diabetic patients. Aliskiren has antifibrotic potential in several experimental models, interfering with the levels of fibrogenic cytokines and oxidative stress. Therefore, its use in diseases in which fibrosis plays an important pathophysiological role is suggested.

A case presentation of patient from northern China with endomyocardial fibrosis.

BACKGROUND: Endomyocardial fibrosis (EMF) is a rare condition and a major cause of death in tropical countries. The etiology of EMF remains elusive, and no specific treatment has been developed yet, therefore it carries poor prognosis. CASE PRESENTATION: An 81-year-old male Chinese patient with a history of long-standing exertional breathlessness, presented with worsening symptoms rapidly evolving to orthopnea. A proper specific treatment was prescribed to the patient in the following days, including diuretics, angiotensin-converting-enzyme inhibitor and beta blockers. The patient died of progressive multiple organ failure. CONCLUSION: Echocardiography is technically limited due to the acoustic shadowing as a result of the calcification. Chest computed tomography is a more accurate diagnostic tool to examine the anatomic distribution and extent of endomyocardial calcification in this rare case.

Myocardial global longitudinal strain: An early indicator of cardiac interstitial fibrosis modified by spironolactone, in a unique hypertensive rat model.

OBJECTIVES: Is global longitudinal strain (GLS) a more accurate non-invasive measure of histological myocardial fibrosis than left ventricular ejection fraction (LVEF) in a hypertensive rodent model. BACKGROUND: Hypertension results in left ventricular hypertrophy and cardiac dysfunction. Speckle-tracking echocardiography has emerged as a robust technique to evaluate cardiac function in humans compared with standard echocardiography. However, its use in animal studies is less clearly defined. METHODS: Cyp1a1Ren2 transgenic rats were randomly assigned to three groups; normotensive, untreated hypertensive or hypertensive with daily administration of spironolactone (human equivalent dose of 50 mg/day). Cardiac function and interstitial fibrosis development were monitored for three months. RESULTS: The lower limit of normal LVEF was calculated to be 75%. After three months hypertensive animals (196±21 mmHg systolic blood pressure (SBP)) showed increased cardiac fibrosis (8.8±3.2% compared with 2.4±0.7% % in normals), reduced LVEF (from 81±2% to 67±7%) and impaired myocardial GLS (from -17±2% to -11±2) (all p<0.001). Myocardial GLS demonstrated a stronger correlation with cardiac interstitial fibrosis (r2 = 0.58, p<0.0001) than LVEF (r2 = 0.37, p<0.006). Spironolactone significantly blunted SBP elevation (184±15, p<0.01), slowed the progression of cardiac fibrosis (4.9±1.4%, p<0.001), reduced the decline in LVEF (72±4%, p<0.05) and the degree of impaired myocardial GLS (-13±1%, p<0.01) compared to hypertensive animals. CONCLUSIONS: This study has demonstrated that, myocardial GLS is a more accurate non-invasive measure of histological myocardial fibrosis compared to standard echocardiography, in an animal model of both treated and untreated hypertension. Spironolactone blunted the progression of cardiac fibrosis and deterioration of myocardial GLS.

Apical hypertrophic cardiomyopathy with apical endomyocardial fibrosis and calcification: Two case reports.

RATIONALE: Apical hypertrophic cardiomyopathy (AHCM) is a rare form of hypertrophic cardiomyopathy which affects predominantly the apex of the left ventricle. Generally, left ventricular enlargement is not present in AHCM; additionally, endomyocardial fibrosis, and calcification are also rare. PATIENT CONCERNS: A 61-year-old female (Case 1) and a 60-year-old female (Case 2) both presented with the symptoms of atypical chest pain, dyspnoea, exercise intolerance, palpitations. DIAGNOSIS: Magnetic resonance and single-photon emission computed tomography (SPECT) revealed apical hypertrophic cardiomyopathy. Furthermore, 2D-transthoracic echocardiogram showed left atrium and ventricular enlargement, as well as endomyocardial fibrosis and calcification. Based on these findings, the patients were diagnosed with AHCM. INTERVENTIONS: Both the patients were treated with ACEI, metoprolol, and aspirin. Additionally, both these patient underwent genetic test. OUTCOMES: The results of the genetic test of the 2 cases for hypertrophic cardiomyopathy (HCM) were negative. However, the gene mutation for dilated cardiomyopathy (TMPO) was detected in one of the cases. No change in condition during follow-up. LESSONS: In past reports, Apical hypertrophic cardiomyopathy has been shown to have a benign prognosis. But in this case report, the imaging studies of the 2 patients suggest a poor prognosis. Furthermore, diagnosing cardiomyopathy should require multimodality imaging examinations to rule out differential diagnoses.

Asiatic acid inhibits cardiac fibrosis throughNrf2/HO-1 and TGF-ß1/Smads signaling pathways in spontaneous hypertension rats.

OBJECTIVE: Asiatic acid (AA) has been suggested to inhibit pulmonary and hepatic fibrosis, while its influence on cardiac fibrosis remains unclear. We aimed to investigate whether AA could inhibit overpressure-induced cardiac fibrosis in spontaneous hypertension rats (SHRs). METHOD: SHRs were treated with AA (20 mg kg-1 day-1) for 12 weeks and cultured cardiac fibroblasts (CFs) were treated with Ang II (10-7 mol/L) in vitro. Markers of oxidative stress were measured and extent of cardiac fibrosis was evaluated with Sirius Red staining. Levels of Superoxide Dismutase (SOD), Malondialdehyde (MDA), reactive oxygen spices (ROS) and Glutathione (GSH) were measured by using commercial assay kits. Collagen deposition was detected. The expression of relative protein and mRNA was measured by Western blot and real-time PCR, respectively. RESULTS: AA reduced systolic blood pressure, attenuated myocardial hypertrophy, reduced college deposition and the expression of collagen I and III, connective tissue growth factor, and plasminogen activator inhibitor-1, in mRNA and protein levels, with inhibition of TGF-ß1 expression, phosphorylation of Smad2/3, and increase of Smad7 expression. AA reduced malondialdehyde and reactive oxygen spices, while increased the activities of superoxide dismutase and glutathione, accompanied with elevation of nuclear translocation of nuclear-factor erythroid 2-related factor 2 (Nrf2) and expression of heme oxygenase (HO-1) and NAD(P)H dehydrogenase [quinone] 1 (NQO-1) in vivo and in vitro. Moreover, pretreating CFs with siRNA for Smad7 or Nrf2 both partially reversed the inhibition of AA on Ang II-induced cardiac fibrosis. CONCLUSION: AA attenuates pressure overload-induced cardiac fibrosis via enhancing of Nrf2/HO-1 and suppressing TGF-ß1/Smads phosphorylation.

The effects of Radix Angelica Sinensis and Radix Hedysari ultrafiltration extract on X-irradiation-induced myocardial fibrosis in rats.

Radix Angelica Sinensis and Radix Hedysari are traditional Chinese medicines that are used for preventing and treating various diseases. This study aimed to investigate the effect and possible underlying mechanisms of Radix Angelica Sinensis and Radix Hedysari ultrafiltration extract (RAS-RH) on X-irradiation-induced cardiac fibrosis in rats. Our data demonstrated that (a) a single dose of total body irradiation (TBI) at 8 Gy resulted in cardiac fibrosis, whereas the control hearts exhibited less collagen and fibrosis. RAS-RH mitigated these morphological injuries. (b) TBI resulted in an increase in the serum levels of transforming growth factor ß1 (TGF-ß1) and troponin-I (TnI). RAS-RH inhibited the release of TBI-induced serum TGF-ß1 and the TnI levels. (c) TBI inhibited the apoptosis of primary rat cardiac fibroblasts, whereas RAS-RH induced the apoptosis of primary rat cardiac fibroblasts after X- irradiation. (d) TBI resulted in an increase in the expression of osteopontin (OPN), c-fos, c-jun, miRNA-21 and collagen1α (COL1α) in primary rat cardiac fibroblasts, and RAS-RH mitigated the TBI-induced increased expression of OPN, c-jun, miRNA-21 and COL1α. In conclusion, these results demonstrate that RAS-RH exerts antifibrotic effects possibly through inducing the apoptosis of fibroblasts, inhibiting the release of serum TGF-ß1, reducing the levels of serum TnI and reducing the expression of OPN, c-jun, miRNA-21 and COL1α. Therefore, RAS-RH may potentially be developed as a medical countermeasure for the mitigation of radiation-induced myocardial fibrosis.

Atorvastatin Prevents Myocardial Fibrosis in Spontaneous Hypertension via Interleukin-6 (IL-6)/Signal Transducer and Activator of Transcription 3 (STAT3)/Endothelin-1 (ET-1) Pathway.

BACKGROUND Hypertension is a leading global disease, and myocardial fibrosis is an important adverse effect of hypertension, seriously threatening human health. The IL-6/STAT3 pathway and endothelin-1 (ET-1) were previously suggested to play a part in myocardial fibrosis. MATERIAL AND METHODS To investigate the role of Atorvastatin (Ato) in spontaneous hypertension, systolic blood pressure (SBP) and left ventricular mass index (LVMI) were measured, and Masson trichrome staining was performed. Furthermore, the relative protein levels of the IL-6/STAT3/ET-1 pathway were tested. RESULTS Ato prevented myocardial fibrosis in spontaneous hypertension rats, especially at the dosage of 50 mg/kg/d. The IL-6/STAT3 pathway was observed to be suppressed by Ato, and ET-1 level in myocardial tissues was also downregulated by Ato. The phosphorylation status of STAT3 was tested after Ato treatment, showing that Ato mainly stimulated the tyr-705 phosphorylation of STAT3. CONCLUSIONS Results of this study may help promote myocardial fibrosis therapy and provide insights into the IL-6/STAT3/ET-1-mediated mechanism in Ato-induced myocardial fibrosis inhibition.

Hirudin Protects Ang II-Induced Myocardial Fibroblasts Fibrosis by Inhibiting the Extracellular Signal-Regulated Kinase1/2 (ERK1/2) Pathway.

BACKGROUND Myocardial fibrosis is closely related to all types of cardiovascular diseases. Hirudin is widely used in the prevention and treatment of cardiovascular diseases and cancers. In this study, we examined the potential role(s) and mechanism of hirudin in angiotensin II (Ang II)-induced myocardial fibrosis. MATERIAL AND METHODS The viability of myocardial fibroblasts, and reactive oxygen species (ROS) rates were measured respectively using cell counting kit-8 (CCK-8) and flow cytometry. Malondialdehyde (MDA) content, the activities of lactate dehydrogenase (LDH), and superoxide dismutase (SOD) were detected by the respective kits. The mRNA and protein levels of fibrosis-related factors were separately assessed by qRT-PCR and western blot. RESULTS Our data revealed that hirudin suppressed the viability of myocardial fibroblasts, and that it relieved the proliferation induced by Ang II in a dose-dependent manner. We also found that hirudin reduced ROS production, LDH activity, and MDA content; however, it enhanced SOD activity. Moreover, while hirudin significantly downregulated the levels of matrix metalloproteinase-2 (MMP-2), MMP-9, fibronectin (FN), transforming growth factor beta 1 (TGF-ß1), collagen-I (COL-I), and COL-III, it upregulated the expression level of tissue inhibitor of metalloproteinases-2 (TIMP-2). Furthermore, phosphorylated extracellular signal-regulated kinase1/2 (p-ERK1/2) was decreased by hirudin, compared to the Ang-II group. CONCLUSIONS Hirudin depressed Ang II-induced myocardial fibroblasts via inhibiting oxidative stress, regulating fibrosis-related factors, and repressing the ERK1/2 pathway.

Astragalosideâ £ against cardiac fibrosis by inhibiting TRPM7 channel.

BACKGROUND: Astragaloside Ⅳ (ASG-Ⅳ, (Fig. 1) is the most active component of Chinese sp. Astragalus membranaceus Bunge (Fabaceae) that has showed antioxidant, antiapoptotic and antiviral activities among others. It is reported to play an important role in cardiac fibrosis (CF), but the mechanism remains unclear. PURPOSE: To investigate the mechanism of ASG-Ⅳ on inhibiting myocardial fibrosis induced by hypoxia. STUDY DESIGN: We studied the relationship between anti-fibrotic effect of ASG-Ⅳ and transient receptor potential cation channel, subfamily M, member 7 (TRPM7) by in vivo and in vitro experiments. METHODS: In vivo, CF was induced by subcutaneous isoproterenol (ISO) for 10 days. Rat hearts were resected for histological experiment and reverse transcription real-time quantitative poly merase chain reaction (RT-qPCR). In vitro, molecular and cellular biology technologies were used to confirm the anti-fibrosis effect underlying mechanism of ASG-Ⅳ. RESULTS: Histological findings and the collagen volume fraction showed that ASG-Ⅳ decreased fibrosis in heart tissues. Hypoxia could stimulate the proliferation and differentiation of cardiac fibroblast which indicated that the degree of fibrosis was increased significantly. Anoxic treatment could also obviously up-regulate the expression of TRPM7 protein and current. ASG-Ⅳ groups showed the opposite results. Knock-down TRPM7 experiment further confirmed the role of TRPM7 channel in hypoxia-induced cardiac fibrosis. CONCLUSION: Our results suggest that the inhibition of hypoxia-induced CF in vivo and in vitro by ASG-IV is associated with reduction of the expression of TRPM7. The moderate inhibition of the TRPM7 channel may be a new strategy for treating cardiac fibrosis.

Anti-Fibrosis Effect of Relaxin and Spironolactone Combined on Isoprenaline-Induced Myocardial Fibrosis in Rats via Inhibition of Endothelial-Mesenchymal Transition.

BACKGROUND: The effect of relaxin and spironolactone combined on myocardial fibrosis has not been reported. Thus, we investigated the effect of the combined therapy on isoprenaline-induced myocardial fibrosis and the mechanism. METHODS: Rats were injected subcutaneously with isoprenaline to induce myocardial fibrosis and underwent subcutaneous injection with relaxin (2 µg·kg-1·d-1) and given a gavage of spironolactone (30 mg·kg-1·d-1) alone or combined for 14 days. In vitro, the endothelial-mesenchymal transition was induced with transforming growth factor ß (TGF-ß) in human umbilical vein endothelial cells (HUVECs) pretreated with relaxin, 200 ng/ml, and/or spironolactone, 1uM. RESULTS: Relaxin and spironolactone used alone or combined improved cardiac function and decreased cardiac weight indices; reduced fibrous tissue proliferation; reduced levels of type I and III collagen; decreased the expression of α-smooth muscle actin (α-SMA) and transforming growth factor-ß1 (TGF-ß1), and increased the expression of cluster of differentiation-31 (CD31) in rats with isoprenaline-induced myocardial fibrosis. In vitro, compared with TGF-ß treatment, relaxin and spironolactone used alone or combined with TGF-ß decreased cell mobility, α-SMA and vimentin levels but increased vascular endothelial cadherin (VE-cadherin) and endothelial CD31levels. Especially, combined therapy had more remarkable effect than relaxin and spironolactone used alone both in vitro and in vivo. CONCLUSION: Relaxin and spironolactone combined affected isoprenaline-induced myocardial fibrosis in rats that the mechanism might be inhibition of the cardiac endothelial-mesenchymal transition.