Rat Cardiac Tissue Research Articles

Moderate-intensity training can ameliorate the process of cardiac apoptosis induced by lithium drug consumption in male Wistar rats

Background and objectiveLithium medication, given its significant role in the treatment or reduction of psychiatric disorders, may exert adverse effects on cardiac tissue. Therefore, this study aimed to investigate the effects of different exercise training intensities on the process of cardiac apoptosis and serum levels of cardiac troponin I (cTnI) resulting from lithium administration in male Wistar rats. MethodologyIn the present experimental study, 35 male Wistar rats were randomly divided into five groups (n=7); Control (CTL), Lithium (Li), High-Intensity training + lithium (HIT-Li), Moderate-Intensity training + lithium (MIT-Li), and Low-Intensity training + lithium (LIT-Li). Lithium drug (dose of 40 mmol/kg dry food weight) and exercise training (5 days per week) were administered for eight weeks. Serum levels of cTnI, mRNA expression of Bcl-2, Bax, and Caspase-3, and histopatholigical changes were assessed by using the ELISA method, Real-Time PCR, and H&E staining, respectively. ResultsThe expression of the Bcl-2 gene was significantly increased in the LIT-Li group compared to the Li group (P = 0.003). Serum levels of cTnI were considereably higher in the Li group compared to the MIT-Li group (P = 0.0001). The expression of the Bax gene, in the LIT-Li, HIT-L, and Li groups, significantly increased compared to the MIT-Li group (P = 0.0001). Histopathological scores decreased in MIT-Li compared to Li group (P = 0.001). ConclusionIt seems that among different exercise intensities, the greatest protective effect against lithium consumption can be observed with moderate exercise intensity, which may potentially modulate factors influencing cardiac apoptosis and reduce lithium toxicity in the cardiac tissue of rats.

Doxorubicin Incorporation into Gold Nanoparticles: An In Vivo Study of Its Effects on Cardiac Tissue in Rats.

Gold nanoparticles (Au-NPs) have been explored as potential vectors for enhancing the antitumor efficacy of doxorubicin (DOX) while minimizing its cardiotoxic effects. However, the impacts of DOX Au-NPs on cardiac function and oxidative stress remain inadequately understood. This study aimed to explore the effects of DOX Au-NPs in comparison to free DOX, focusing on oxidative stress markers, inflammation, ultrastructural changes, and cardiac function. Male rats were divided into the following four groups: control, citrate Au-NPs, DOX, and DOX Au-NPs. Cardiac function was assessed using echocardiography, and oxidative stress was evaluated through Nrf2, malondialdehyde (MDA) and superoxide dismutase (SOD) levels, and the GSH/GSSG ratio. The ultrastructure of cardiac tissue was assessed by transmission electron microscopy (TEM). Rats treated with DOX Au-NPs exhibited significant cardiac dysfunction, as indicated by a reduction in fractional shortening and ejection fraction. Oxidative stress markers, including elevated MDA levels and a reduced GSH/GSSG ratio, were significantly worse in the DOX Au-NP group. SOD levels decreased, indicating compromised antioxidant defenses. Citrate Au-NPs also caused some alterations in cardiac function and ultrastructure but without other molecular alterations. DOX Au-NPs failed to mitigate cardiotoxicity, instead exacerbating oxidative stress and cardiac dysfunction. DOX Au-NPs possess cardiotoxic effects, necessitating further investigation into alternative nanoparticle formulations or therapeutic combinations to ensure both efficacy and safety in cancer treatment.

Melatonin protects against chromium induced oxidative stress-mediated changes in energy metabolism of rat hepatic, cardiac and renal tissues

Chromium (Cr) is one of the most prevalent and potentially hazardous heavy metal found in the environment that can cause carcinogenic, genotoxic, and organ-specific irreversible complications. The most severe adverse outcome of Cr on humans involves oxidative stress. Melatonin was evidenced to alleviate such stress with various mechanisms including antioxidative potential and metal chelation. Male Wistar rats were divided into 4 groups and treated for 14 days. The first group (control) was treated with vehicle; the second group was orally administered with melatonin (20 mg/kg b.w./day); the third group was injected with sodium dichromate dihydrate (5 mg/kg bw, s.c. every alternate day); and the fourth group was administered with melatonin, 30 min before Cr administration. The treatment of rats with Cr (VI) was found to affect the metabolic pathways by altering the activities of enzymes possibly through uncompetitively binding with them. The current study also demonstrated that melatonin efficiently preserved the glucose levels and blood lipid profile. Moreover, melatonin was further found to protect the activities of glycolytic, Krebs’ cycle, and ETC enzymes. Further, melatonin pre-treatment reduced the production of O2.− anion free radical and Ca2+ overload to protect the mitochondria at the ultrastructural level and reduced DNA damage to some extent. Therefore, this research strongly recommends melatonin as a therapeutic molecule against Cr-induced oxidative stress-mediated liver, heart, and kidney disorders.

An Investigation of the Hypoglycemic and Antioxidant Activity of Pimpinella tirupatiensis in STZ-Induced Diabetic Rat Cardiac Tissue

An Investigation of the Hypoglycemic and Antioxidant Activity of Pimpinella tirupatiensis in STZ-Induced Diabetic Rat Cardiac Tissue

Cardio and Neuroprotective Effects of Naringenin Against Aluminum Chloride-induced Oxidative Stress in Wistar Rats

Background: Plant secondary metabolites have been reported to offer a wide variety of medicinal purposes, including protection against heavy metal toxicity. Objectives: This study aimed to investigate the potentiality of naringenin a flavonoid in ameliorating the antioxidant defense system of neural and cardiac cells against aluminum chloride (AlCl3 ) toxicity in rats. Methods: The rats were divided into control (group 1), AlCl3 -treated (2), AlCl3+Naringenin-treated (3), and Naringenin-treated (4) groups. During experimentation, group 2 received an oral dose of 100 mg/kg/BW of AlCl3 , and group 3 received 100 mg/kg/BW of AlCl3 and 50 mg/ kg/BW of naringenin. In addition, group 4 received 50 mg/kg/BW of naringenin each day, while group 1 and all groups received a normal diet and water ad libitum for 30 days. The animals were sacrificed, and then blood, brain, and heart tissues were collected for biochemical and histological studies. Results: The results revealed that naringenin administration ameliorates the antioxidant defense system (catalase [CAT], superoxide dismutase [SOD], glutathione peroxidase [GPx], and glutathione transferase) in AlCl3 toxicity in neural and cardiac tissues. AlCl3 caused oxidative tissue damage, showing a significant increase in malondialdehyde (MDA) (P<0.05) in both tissues. The levels of neurotransmitter acetylcholine esterase, nitric oxide, and lactate dehydrogenase (LDH) in the rats of group 3 were significantly (P<0.05) higher compared with AlCl3 -intoxicated rats. Furthermore, the AlCl3 -administered group had significantly (P<0.05) elevated levels of total cholesterol (TC), triglycerides, and low-density lipoprotein-cholesterol, with reduced high-density lipoprotein-cholesterol levels in comparison to the naringenin-treated and control groups. Naringenin treatment normalized the lipid profile. Histological analysis using the hematoxylin and eosin staining method revealed that AlCl3 caused degenerative changes in the cerebellum and cardiac tissues, which were ameliorated by co-treatment with naringenin. Conclusion: Naringenin has the potential to mitigate AlCl3 -induced oxidative stress (OS) in the neural and cardiac tissues of rats by enhancing the antioxidant defense system and reversing tissue injuries in the brain and heart.

Impaired Cardiac AMPK (5'-Adenosine Monophosphate-Activated Protein Kinase) and Ca2+-Handling, and Action Potential Duration Heterogeneity in Ibrutinib-Induced Ventricular Arrhythmia Vulnerability.

We recently demonstrated that acute administration of ibrutinib, a Bruton's tyrosine kinase inhibitor used in chemotherapy for blood malignancies, increases ventricular arrhythmia (VA) vulnerability. A pathway of ibrutinib-induced vulnerability to VA that can be modulated for cardioprotection remains unclear. The effects of ibrutinib on cardiac electrical activity and Ca2+ dynamics were investigated in Langendorff-perfused hearts using optical mapping. We also conducted Western blotting analysis to evaluate the impact of ibrutinib on various regulatory and Ca2+-handling proteins in rat cardiac tissues. Treatment with ibrutinib (10 mg/kg per day) for 4 weeks was associated with an increased VA inducibility (72.2%±6.3% versus 38.9±7.0% in controls, P<0.002) and shorter action potential durations during pacing at various frequencies (P<0.05). Ibrutinib also decreased heart rate thresholds for beat-to-beat duration alternans of the cardiac action potential (P<0.05). Significant changes in myocardial Ca2+ transients included lower amplitude alternans ratios (P<0.05), longer times-to-peak (P<0.05), and greater spontaneous intracellular Ca2+ elevations (P<0.01). We also found lower abundance and phosphorylation of myocardial AMPK (5'-adenosine monophosphate-activated protein kinase), indicating reduced AMPK activity in hearts after ibrutinib treatment. An acute treatment with the AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside ameliorated abnormalities in action potential and Ca2+ dynamics, and significantly reduced VA inducibility (37.1%±13.4% versus 72.2%±6.3% in the absence of 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, P<0.05) in hearts from ibrutinib-treated rats. VA vulnerability inflicted by ibrutinib may be mediated in part by an impairment of myocardial AMPK activity. Pharmacological activation of AMPK may be a protective strategy against ibrutinib-induced cardiotoxicity.

Effect of Stanozolol and/or Cannabis Abuse on Hypertrophic Mechanism and Oxidative Stress of Male Albino Rat Cardiac Tissue in Relation to Exercise: A Sport Abuse Practice

Adolescents commonly co-abuse many drugs including anabolic androgenic steroids either they are athletes or non-athletes. Stanozolol is the major anabolic used in recent years and was reported grouped with cannabis. The current study aimed at evaluating the biochemical and histopathological changes related to the hypertrophic effects of stanozolol and/or cannabis whether in condition of exercise practice or sedentary conditions. Adult male Wistar albino rats received either stanozolol (5 mg/kg, s.c), cannabis (10 mg/kg, i.p.), and a combination of both once daily for two months. Swimming exercise protocol was applied as a training model. Relative heart weight, oxidative stress biomarkers, cardiac tissue fibrotic markers were evaluated. Left ventricular morphometric analysis and collagen quantification was done. The combined treatment exhibited serious detrimental effects on the heart tissues. It increased heart tissue fibrotic markers (Masson’s trichrome stain (p < 0.001), cardiac COL3 (p < 0.0001), and VEGF-A (p < 0.05)), lowered heart glutathione levels (p < 0.05) and dramatically elevated oxidative stress (increased malondialdehyde (p < 0.0001) and 8-OHDG (p < 0.0001)). Training was not ameliorating for the observed effects. Misuse of cannabis and stanozolol resulted in more hypertrophic consequences of the heart than either drug alone, which were at least largely assigned to oxidative stress, heart tissue fibrotic indicators, histological alterations, and morphometric changes.

Exposure to emissions generated by 3-dimensional printing with polycarbonate: effects on peripheral vascular function, cardiac vascular morphology and expression of markers of oxidative stress in male rat cardiac tissue

ABSTRACT Three-dimensional (3D) printing with polycarbonate (PC) plastic occurs in manufacturing settings, homes, and schools. Emissions generated during printing with PC stock and bisphenol-A (BPA), an endocrine disrupter in PC, may induce adverse health effects. Inhalation of 3D printer emissions, and changes in endocrine function may lead to cardiovascular dysfunction. The goal of this study was to determine whether there were any changes in markers of peripheral or cardiovascular dysfunction in animals exposed to PC-emissions. Male Sprague Dawley rats were exposed to PC-emissions generated by 3D printing for 1, 4, 8, 15 or 30 d. Exposure induced a reduction in the expression of the antioxidant catalase (Cat) and endothelial nitric oxide synthase (eNos). Endothelin and hypoxia-induced factor 1α transcripts increased after 30 d. Alterations in transcription were associated with elevations in immunostaining for estrogen and androgen receptors, nitrotyrosine, and vascular endothelial growth factor in cardiac arteries of PC-emission exposed animals. There was also a reduction eNOS immunostaining in cardiac arteries from rats exposed to PC-emissions. Histological analyses of heart sections revealed that exposure to PC-emissions resulted in vasoconstriction of cardiac arteries and thickening of the vascular smooth muscle wall, suggesting there was a prolonged vasoconstriction. These findings are consistent with studies showing that inhalation 3D-printer emissions affect cardiovascular function. Although BPA levels in animals were relatively low, exposure-induced changes in immunostaining for estrogen and androgen receptors in cardiac arteries suggest that changes in the action of steroid hormones may have contributed to the alterations in morphology and markers of cardiac function.

A Perspective on Male Contraceptive Therapeutics of Hydro-ethanol Extract of Seeds of &lt;i&gt;Luffa acutangula (L.) Roxb.&lt;/i&gt; in Human and Albino Rat: An &lt;i&gt;In-vitro&lt;/i&gt; Meta-Analysis Study

Traditionally Luffa acutangula (L.) Roxb. has been utilized as an herbal contraceptive. This in-vitro study has been performed to search out the male contraceptive efficacy of hydro-ethanol (60:40) extract of Luffa acutangula (LAHEE) seeds in a dose-specific manner (1, 2, and 4 mg/ml of in-vitro media). The percentages of motile, viable, hypo-osmotic swelled (HOS), and acrosomal intact of human and rat sperms were declined significantly (p&lt;0.05) at the above-mentioned doses of LAHEE-exposed groups against the placebo group. The inhibitory concentration 50% value (IC50) of LAHEE was 2.5 mg/ml in human and 1.2 mg/ml in rat spermatozoa immobilization. The ∆5,3β and 17β hydroxysteroid dehydrogenase (HSD) activities of rat’s testicular tissues were inhibited significantly at p&lt;0.05 in LAHEE-treated groups than the placebo group. Activities of superoxide dismutase (SOD) and catalase were significantly inhibited (p&lt;0.05) along with the significant increment (p&lt;0.05) in the quantity of thiobarbituric acid reactive substances (TBARS) in rat’s testes and epididymis, sperm pellets of humans and rats in LAHEE-treated groups against the placebo group without any significant difference (p&gt;0.05) in above said sensors in the liver and cardiac tissues of rats. The non-toxic nature of LAHEE was indicated by no significant alterations (p&gt;0.05) in the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) after LAHEE exposure in said tissues of rats. The LC-MS study of LAHEE identified the presence of oleic acid, dihydroquercetin, luteolin-7-glucoside, formononetin, luteolin 8-C-pentoside-6-C-hexoside, pterosin B, boldine and berberine. These findings interpreted that the LAHEE possesses spermiological inhibitory and hypo-testicular activities, which indicate a promising possibility to develop a potent herbal male contraceptive agent from this plant extract.

Chronic Ethanol Decreases the Left Ventricular Cardiac Performance

Introduction: Spaced fiber bundles, less evident cell striations, deposition of collagen fiber bundles, and increased presence of fibroblasts in the cardiac tissue of rats that voluntarily and chronically ingested ethanol were observed by our research group. In addition, we observed increased proliferation and cell death of cardiomyocytes. To find out whether these changes lead to impaired heart functionality, some clinical tests were performed. Aim: to investigate whether chronic ethanol decreases the left ventricular performance assessed by exercise testing, electrocardiogram, and echocardiogram of male and female UChB strain rats. Material and methods: ten adult males and ten adult females, Wistar strain rats, named UChB (University of Chile), spontaneous high ethanol drinkers (consumption greater than 2 g ethanol / Kg body weight/day), and ten male UChB rats and ten adults female UChB rats, not exposed to ethanol, UChBC rats (controls) were used. Cardiac performance was evaluated by the stress test, electrocardiogram, and echocardiogram. Results: Exposed females showed ventricular morphological changes in the heart. The exposed females and males had the highest heart relative weight with females being larger than males. The exposed females showed altered electrocardiogram and echocardiogram. Conclusion: Chronic ethanol decreases the left ventricular cardiac performance in rats. Females are more sensitive to changes in cardiac electrical conduction.

Study on mechanism of Aconitum pendulum in treating rheumatoid arthritis based on toxicity efficacy evaluation and metabonomics

The study aims to investigate the effects and potential mechanism of raw and processed Aconitum pendulum Busch on rheumatoid arthritis(RA) and analyze their toxicity attenuating and efficacy retaining effects. The bovine type Ⅱ collagen-induced arthritis(CIA) rat model was established. The weight, cardiac index, immune organ index, and arthritis index of the rats were recorded and calculated after administration. ELISA was used to measure the expressions of creatine kinase(CK), cardiac troponin T(cTnT), and multiple factors. The pathological morphological changes in heart tissue and ankle joint tissue were observed by hematoxylin-eosin staining. Connexin 43(Cx43) expression in the hearts of CIA rats was detected via immunohistochemical method. The levels of endogenous metabolites in the serum of CIA rats were detected by UPLC-Q-TOF-MS. Potential biomarkers were screened, and related metabolic pathways were analyzed. The results showed that raw A. pendulum could induce local myocardial fiber degeneration and necrosis, increase the cardiac index, decrease the average positive area of Cx43 expression significantly, and increase the expressions of CK and cTnT in cardiac tissue of rats. Meanwhile, raw A. pendulum could decrease the immune organ index, interleukin-6(IL-6), and other inflammatory cytokine contents in the serum and improve the damaged synovium and joint surface of CIA rats, with toxicity and efficacy coexisting. The Zanba stir-fired A. pendulum could reduce the index of arthritis, immune organ index, and content of IL-6 and inflammatory cytokines in serum and improve damaged synovium and joint surface of CIA rats with no obvious cardiac toxicity, showing significant toxicity attenuating and efficacy retaining effects. A total of 19 potential biomarkers of raw A. pendulum and Zanba stir-fired A. pendulum against RA were screened by serum metabolomics, including glycerophospholipid metabolism, glycine, serine, and threonine metabolism, arginine and proline metabolism, and steroid hormone synthesis. In conclusion, Xizang medicine A. pendulum is preventive and curative for RA. Raw A. pendulum has certain cardiotoxicity, and Zanba stir-fired A. pendulum has significant toxicity attenuating and efficacy retaining effects. The anti-RA mechanism may be related to the regulation of glycerophospholipid and amino acid metabolism.

Punicalagin attenuates isoproterenol-induced myocardial infarction through nuclear factor erythroid 2-related factor 2/silent information regulator transcript-1-mediated inhibition of inflammation and cardiac stress markers in experimental animal models.

Myocardial infarction (MI) is a significant global health issue and the leading cause of death. Myocardial infarction (MI) is characterized by events such as damage to heart cells and stress generated by inflammation. Punicalagin (PCN), a naturally occurring bioactive compound found in pomegranates, exhibits a diverse array of pharmacological effects against many disorders. This study aimed to assess the preventive impact of PCN, with its potential anti-inflammatory and antioxidant properties, on myocardial injury caused by isoproterenol (ISO) in rats and elucidate the possible underlying mechanisms. Experimental rats were randomly categorized into four groups: control group (fed a regular diet for 15 days), PCN group (orally administered PCN at 50 mg/kg body weight (b.w.) for 15 days), ISO group (subcutaneously administered ISO (85 mg/kg b.w.) on days 14 and 15 to induce MI), and PCN+ISO group (orally preadministered PCN (50 mg/kg b.w.) for 15 days and administered ISO (85 mg/kg b.w.) on days 14 and 15). The rat cardiac tissue was then investigated for cardiac marker, oxidative stress marker, and inflammatory marker expression levels. PCN prevented ISO-induced myocardial injury, suppressing the levels of creatine kinase-myocardial band, C-reactive protein, homocysteine, cardiac troponin T, and cardiac troponin I in the rats. Moreover, PCN treatment reversed (P<0.01) the ISO-induced increase in blood pressure, attenuated lipid peroxidation markers, and depleted both enzymatic and nonenzymatic markers in the rats. Additionally, PCN inhibited (P<0.01) ISO-induced overexpression of oxidative stress markers (p-38, p-c-Jun N-terminal kinase, and p-extracellular signal-regulated kinase 1), inflammatory markers (nuclear factor-kappa B, tumor necrosis factor-alpha, and interleukin-6), and matrix metalloproteinases and decreased the levels (P<0.01) of apoptosis proteins in the rats. Nuclear factor erythroid 2-related factor 2/silent information regulator transcript-1 (Nrf2/Sirt1) is a major cellular defense protein that regulates and scavenges oxidative toxic substances through apoptosis. Therefore, overexpression of Nrf2/Sirt1 to inhibit inflammation and oxidative stress is considered a novel target for preventing MI. PCN also significantly enhanced the expression of Nrf2/Sirt1 in ISO-induced rats. Histopathological analyses of cardiac tissue revealed that PCN treatment exhibited a protective effect on the heart tissue, mitigating damage. These findings show that by activating the Nrf2/Sirt1 pathway, PCN regulates oxidative stress, inflammation, and apoptosis, hence providing protection against ISO-induced myocardial ischemia.

504 Dihydroxyacetone, a combustion of electronic cigarettes, promotes cardiac-specific injury through metabolic and mitochondrial imbalances

OBJECTIVES/GOALS: Electronic cigarettes have become increasingly popular, with various combustion products generated in the process. Dihydroxyacetone (DHA), a carbohydrate made during the heating process. Exposures may reach high micromolar to low millimolar doses of DHA per day and no studies have been done to understand the effects of DHA in the heart. METHODS/STUDY POPULATION: Here, we examine if DHA contributes to these using rat cardiomyocytes, H9c2 cells, and rat cardiac tissues to DHA evaluating metabolic and mitochondrial effects. Using the cells, we will investigate metabolic and mitochondrial pathways using Seahorse, protein expression changes in nutrient sensing pathways, and understand dose-dependent effects of DHA in the heart. Metabolite pools will also be evaluated to understand the changes promoted by DHA. Oxidative stress as previously observed in other cell models will also be measured. Key findings in the cardiac cells will be investigated in the cardiac tissues exposed to DHA. RESULTS/ANTICIPATED RESULTS: We have previously shown DHA induces oxidative stress, metabolic changes, and mitochondrial dysfunction in various cell line models. Interestingly, these effects are highly cell-type dependent. E-cigarettes are known to have toxic cardiac effects, including arterial stiffness, endothelial dysfunction, vascular injury, and oxidative stress. Changes in glycolytic, fatty acid synthesis, and the citric acid cycle enzymes and metabolites were found in the H9c2 cells. We also observed increased mitochondrial ROS and fuel changes due to DHA exposure. In DHA exposed cardiac tissues, we observed oxidative stress and mitochondrial fission and fusion dynamics altered. DISCUSSION/SIGNIFICANCE: These data suggest further study at physiologically relevant doses is warranted to understand how DHA inhaled impacts the long-term health of vapers. As well as the regulation of DHA in e-cigarettes as it has been deemed as safe for topical applications and warned against inhalation.

Hyperbaric Oxygen Upregulates Mst1 to Activate Keap1/Nrf2/HO-1 Pathway Resisting Oxidative Stress in a Rat Model of Acute Myocardial Infarction.

This study aimed to investigate the protective effects and mechanisms of hyperbaric oxygen (HBO) preconditioning in a rat model of acute myocardial infarction (MI) established by ligation of the left anterior descending (LAD) coronary artery. Microarray, real-time PCR, and western blotting (WB) results demonstrated that the Mst1 gene was downregulated in the heart tissue of the MI rat model. HBO preconditioning significantly increased Mst1 expression in cardiac tissues of rats after MI modeling. Lentiviral infection was used to silence the Mst1 gene in rats treated with HBO to probe the effect of Mst1 on HBO cardioprotection. HBO preconditioning decreased heart infarct size and ameliorated cardiac function in MI rats, whereas Mst1 silencing reversed the effect of HBO administration, as indicated after heat infarct size determination via TTC staining, histological examination via HE staining, and measurements of cardiac function. HBO preconditioning reduced oxidative stress and inflammation in cardiac tissue of MI rat model, evidenced by alteration of malondialdehyde (MDA), 8-hydroxy-2-deoxyguanosine (8-OHdG), and protein carbonyl contents, as well as production of inflammation-associated myeloperoxidase (MPO), IL-1β, and TNF-α. These findings provide a new signaling mechanism through which HBO preconditioning can protect against acute MI injury through the Mst1-mediating Keap1/Nrf2/HO-1-dependent antioxidant defense system.

Downregulation of salusins alleviates hypertrophic cardiomyopathy via attenuating oxidative stress and autophagy

IntroductionSalusins, which are translated from the alternatively spliced mRNA of torsin family 2 member A (TOR2A), play a vital role in regulation of various cardiovascular diseases. However, it remains unclear precisely regarding their roles in hypertrophic cardiomyopathy (HCM). Therefore, this study was conducted to explore therapeutic effect and the underlying mechanisms of salusins on HCM.Material and methodsIn vivo experiments, Sprague–Dawley rats were used to induce HCM model by angiotensin (Ang) II infusion for 4 weeks. The rats were randomly divided into four groups, namely, Saline + Control shRNA (n = 7), Ang II + Control shRNA (n = 8), Saline + TOR2A shRNA (n = 7), and Ang II + TOR2A shRNA groups (n = 8). After HCM induction, doppler echocardiography is recommended to evaluate heart function. In vitro experiments, primary neonatal rat cardiomyocytes (NRCMs) and cardiac fibroblasts (NRCFs) were obtained from newborn rats, and were treated with Ang II (10–6 M) for 24 h.ResultsAfter treatment with Ang II, levels of salusin-α and salusin-β were elevated in serum and cardiac tissues of rats and in the neonatal rat cardiomyocytes and cardiac fibroblasts. Downregulation of salusins alleviated the Ang II-induced cardiac hypertrophy by suppressing the increased atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and beta-myosin heavy chain (β-MHC) and cardiac fibrosis by blocking collagen I, collagen III and transforming growth factor-beta (TGF-β), and it also attenuated oxidative stress by suppressing the increased reactive oxygen species (ROS) and malondialdehyde (MDA) levels and reversing the decreased superoxide dismutase (SOD) activity and autophagy by inhibiting the increased microtubule-associated protein light chain 3B (LC3B), Beclin1, autophagy related gene (Atg) 3 and Atg5 in the cardiac tissues of Ang II-infused rats and in the Ang II-treated NRCMs.ConclusionsAll these findings suggest that the levels of salusins were elevated in the HCM, and targeting of salusins contributes to alleviation of cardiac hypertrophy and fibrosis probably via attenuating oxidative stress and autophagy. Accordingly, targeting of salusins may be a strategy for HCM therapy.

Suxiao Jiuxin Pill alleviates myocardial ischemia/reperfusion-induced autophagy via miR-193a-3p/ALKBH5 pathway

BackgroundMyocardial ischemia/reperfusion injury (MIRI) poses a formidable challenge to cardiac reperfusion therapy due to the absence of effective clinical interventions. Methylation of N6-methyladenosine (m6A), which is the most common post-transcriptional modifications occurring within mammalian mRNA, is believed to be involved in MIRI by modulating autophagy. MicroRNAs (miRNAs) play a crucial role in regulating gene expression at the post-transcriptional level and have been implicated in the regulation of m6A methylation. Suxiao Jiuxin Pill (SJP) is extensively used in China for the clinical treatment of angina pectoris and confers benefits to patients with acute coronary syndrome who have received percutaneous coronary intervention. However, the precise mechanisms underlying SJP intervention in MIRI remain unclear. PurposeThis study aimed to demonstrate, both in vivo and in vitro, that SJP could alleviate autophagy in MIRI by regulating miR-193a-3p to target and upregulate the demethylase ALKBH5. MethodsAn in vitro hypoxia/reoxygenation model was established using H9c2 cells, while an in vivo MIRI model was established using Wistar rats. A lentivirus harboring the precursor sequence of miR-193a-3p was employed for its overexpression. Adeno-associated viruses were used to silence both miR-193a-3p and ALKBH5 expressions. Cardiac function, infarct size, and tissue structure in rats were assessed using echocardiography, triphenyl tetrazolium chloride (TTC) staining, and HE staining, respectively. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) was employed to detect the levels of apoptosis in rat cardiac tissue. m6A methylation levels were assessed using colorimetry. GFP-RFP-LC3B was used to monitor autophagic flux and transmission electron microscopy was used to evaluate the development of autophagosomes. Western Blot and qRT-PCR were respectively employed to assess the levels of autophagy-related proteins and miR-193a-3p. ResultsSJP alleviated autophagy, preserved cardiac function, and minimized myocardial damage in the hearts of MIRI rats. SJP attenuated autophagy in H/R H9C2 cells. Elevated levels of miR-193a-3p were observed in the cardiac tissues of MIRI rats and H/R H9C2 cells, whereas SJP downregulated miR-193a-3p levels in these models. ALKBH5, a target gene of miR-193, is negatively regulated by miR-193a-3p. Upon overexpression of miR-193a-3p or silencing of ALKBH5, m6A methylation decreased, and the autophagy-attenuating effects of SJP and its components, senkyunolide A and l-borneol, were lost in H/R H9C2 cells, whereas in MIRI rats, these effects were not abolished but merely weakened. Further investigation indicated that the METTL3 inhibitor STM2475, combined with the silencing of miR-193a-3p, similarly attenuated autophagy in the hearts of MIRI rats. This suggests that a reduction in m6A methylation is involved in autophagy alleviation. ConclusionWe demonstrated that SJP mitigates autophagy in MIRI by downregulating miR-193a-3p, enhancing ALKBH5 expression, and reducing m6A methylation, a mechanism potentially attributed to its constituents, senkyunolide A and l-borneol.

14,15-Dihydroxyeicosatrienoic acid, a soluble epoxide hydrolase metabolite in blood, is a predictor of anthracycline-induced cardiotoxicity – a hypothesis generating study

BackgroundEarly identification of patients susceptible to chemotherapy-induced cardiotoxicity could lead to targeted treatment to reduce cardiac dysfunction. Rats treated with doxorubicin (DOX), a chemotherapeutic agent, have increased cardiac expression of 14,15-dihydroxyeicosatrienoic acid (14,15-DHET), a bioactive lipid implicated in hypertension and coronary artery disease. However, the utility of 14,15-DHET as plasma biomarkers was not defined. The aim of this study is to investigate if levels of 14,15-DHET are an early blood biomarker to predict the subsequent occurrence of cardiotoxicity in cancer patients after chemotherapy.MethodsH9c2 rat cardiomyocytes were treated with DOX (1 μM) for 2 h and levels of 14,15-DHET in cell media was quantified at 2, 6 or 24 h in media after DOX treatment. Similarly, female Sprague–Dawley rats were treated with DOX for two weeks and levels of 14,15-DHET was assessed in plasma at 48 h and 2 weeks after DOX treatment. Changes in brain natriuretic peptide (BNP) mRNA, an early cardiac hypertrophy process, were determined in the H9c2 cells and rat cardiac tissue. Results were confirmed in human subjects by assessment of levels of 14,15-DHET in plasma of breast cancer patients before and after DOX treatment and left ventricular ejection fraction (LVEF), a clinical marker of cardiotoxicity.ResultsLevels of 14,15-DHET in cell media and rat plasma increased ~ 3-fold and was accompanied with increase in BNP mRNA in H9c2 cells and rat cardiac tissue after DOX treatment. In matched plasma samples from breast cancer patients, levels of 14,15-DHET were increased in patients that developed cardiotoxicity at 3 months before occurrence of LVEF decrease.ConclusionsTogether, these results indicate that levels of 14,15-DHET are elevated prior to major changes in cardiac structure and function after exposure to anthracyclines. Increased levels of 14,15-DHET in plasma may be an important clinical biomarker for early detection of anthracycline-induced cardiotoxicity in cancer patients.

Exosomes from Adipose-Derived Mesenchymal Stem Cells Protect Against Cyclophosphamide-Induced Cardiotoxicity in Rats.

A certain dosage of cyclophosphamide (CYP) in clinical applications contributes to severe cardiotoxicity. Herein, this study explored the impact of adipose-derived mesenchymal stem cell (AdMSC)-exosomes (Exos) on CYP-induced cardiotoxicity.AdMSCs and AdMSCs-Exos were isolated and identified. CYP was utilized for developing a cardiotoxicity rat model, after which blood was collected and then the serum contents of cardiac injury-related indexes (creatine kinase-MB, lactate dehydrogenase, aspartate aminotransferase, and alkaline phosphatase) were detected with enzyme-linked immunosorbent assay kits. Oxidative stress (OS)-related indicators were measured with the corresponding kits. Myocardial pathological changes and collagen fibrosis were tested with hematoxylin-eosin and Masson staining, and apoptosis-related and autophagy-related proteins in rat cardiac tissues with immunohistochemistry and Western blot assays, respectively.AdMSCs and AdMSCs-Exos were successfully isolated. AdMSCs-Exos could target rat hearts. AdMSCs-Exos improved cardiac function and diminished the content of the cardiac injury-related indexes in CYP rats. In addition, AdMSCs-Exos reduced CYP-induced cardiac fibrosis, OS, apoptosis, and autophagy in rats.AdMSCs-Exos alleviated CYP-induced cardiotoxicity in rats via the repression of OS, apoptosis, and autophagy.

Ultrastructural Changes and Inflammatory Processes of Day-Dependent Cisplatin Administration on Rat Cardiac Tissue

Aim: Cisplatin (CP) is used to treat a variety of cancers as a chemotherapeutic agent. This drug has also severe side effects and its use exhibits serious toxicity in a number of organs, including kidney and heart. The aim of the present study was to evaluate the ultrastructural and inflammatory changes induced by CP treatment in rat cardiac tissue in a time-dependent manner.&#x0D; Material and Methods: Rats were randomly divided into three experimental groups; control (only saline), CP D2 (treated with CP 2.5 mg/kg/day for 2 days), and CP D7 (treated with CP 2.5 mg/kg/day for 7 days). Cardiac tissues were examined under an electron microscope. Inflammation markers including tumor necrosis factor-α (TNF-α) and interleukin 1β (IL-1β) were analyzed by immunohistochemistry. In addition, electrocardiography was performed to measure the electrical activity.&#x0D; Results: The ultrastructural analysis of the CP D7 group revealed that myofibrils were disrupted and disorganized, mitochondria degenerated, and interstitial edema developed. When compared to the control and CP D2 groups, there was a noticeable increase in the level of TNF-α and IL-1β expression in the CP D7 group according to immunohistochemistry results. Electrocardiography showed that RR interval was longer in CP D7 than CP D2 and control groups.&#x0D; Conclusion: CP for 7 days damaged the ultrastructural morphology in cardiac tissue. Therefore, these findings suggest that the potential therapeutic approaches to reduce mitochondrial damage and inflammation against toxicity caused by CP may provide for clinically significant prevention when using the drug for an extended period of time.

Mitochondrial biogenesis and apoptosis as underlying mechanisms involved in the cardioprotective effects of Gallic acid against D-galactose-induced aging.

Aging is a main risk factor for the development of cardiovascular diseases (CVDs). Gallic acid (GA) is a phenolic compound derived from a wide range of fruits. GA has a wide spectrum of pharmacological properties, including anti-oxidative, anti-inflammatory, and cardioprotective effects. This research was conducted to determine the cardioprotective effect of GA on cardiac hypertrophy in aged rats. Following histological evaluation and through observing the heart, we found that GA improved the cardiac hypertrophy induced by D-galactose (D-GAL) in cardiac cells. To clarify the causes for this anti-aging effect, we evaluated the malonic dialdehyde levels and antioxidant enzyme activity in rat cardiac tissue. The levels of lactate dehydrogenase (LDH) and creatine kinase (CK-MB) in serum were measured. The levels of genes related to mitochondrial biogenesis, mitophagy, and apoptosis in cardiac tissue were surveyed. The findings represented that GA ameliorated antioxidant enzyme activity while significantly decreasing the malonic dialdehyde levels. Real-time PCR analysis proposed that GA effectively improved mitochondrial biogenesis in the heart via regulating the expression levels of Sirtuin 1 (SIRT1), PPARγ coactivator 1α (PGC1-α), nuclear factor erythroid 2-related factor 2 (Nrf2), and mitochondrial transcription factor A (TFAM). GA also mitigated apoptosis in the heart by modulating the expression levels of B-cell lymphoma protein 2 (Bcl-2) and Bcl-2-associated X (Bax). In addition, GA improved serum LDH and CK-MB levels. GA may alleviate aging-induced cardiac hypertrophy via anti-oxidative, mitoprotective, and anti-apoptotic mechanisms.