Sprague-Dawley Research Articles

A new method to predict return of spontaneous circulation by peripheral intravenous analysis during cardiopulmonary resuscitation: a rat model pilot study

Abstract Background Enhancing venous return during cardiopulmonary resuscitation (CPR) can lead to better hemodynamics and improved outcome after cardiac arrest (CA). Peripheral Intravenous Analysis (PIVA) provides feedback on venous flow changes and may indicate an increase in venous return and cardiac output during CPR. We hypothesize PIVA can serve as an early indicator of increased venous return, preceding end-tidal CO2 (etCO2) increase, before the return of spontaneous circulation (ROSC) in a rat model of CA and CPR. Results Eight male Wistar rats were intubated and ventilated, and etCO2 was measured. Vessels were cannulated in the tail vein, femoral vein, femoral artery, and central venous and connected to pressure transducers. Ventilation was discontinued to achieve asphyxial CA. After 8 min, CPR began with ventilation, epinephrine, and automated chest compressions 200 times per minute until mean arterial pressure increased to 120 mmHg. Waveforms were recorded and analyzed. PIVA was calculated using a Fourier transformation of venous waveforms. Data are mean ± SE. Maximum PIVA values occurred in the tail vein 34.7 ± 2.9 s before ROSC, with subsequent PIVA peaks in femoral vein and centrally at 30.9 ± 5.4 and 25.1 ± 5.0 s, respectively. All PIVA peaks preceded etCO2 increase (21.5 ± 3.2 s before ROSC). Conclusion PIVA consistently detected venous pressure changes prior to changes in etCO2. This suggests that PIVA has the potential to serve as an important indicator of venous return and cardiac output during CPR, and also as a predictor of ROSC.

Bactericidal effect of far ultraviolet-C irradiation at 222 nm against bacterial peritonitis

Far ultraviolet-C irradiation at 222 nm has potent bactericidal effects against severe infections such as peritonitis, with minimal cytotoxicity. Bacterial peritonitis due to bowel perforation is a serious condition with high mortality despite current treatments. This study investigated the safety and efficacy of intraperitoneal far ultraviolet-C irradiation at 222 nm. In vitro experiments optimized the fluid conditions for bacterial or protein concentrations prior to in vivo evaluation. In vivo efficacy was assessed in a rat peritonitis model induced by Escherichia coli, measuring intra-abdominal bacterial concentration, blood cytokine levels, and mortality rates. Safety was evaluated by analyzing cyclobutane pyrimidine dimers as markers of DNA damage in five abdominal organs: stomach, small intestine, colon, liver, and spleen. Statistical analyses employed parametric methods for normally distributed data and non-parametric methods for data without normality. Optimal in vitro conditions included 106 CFU/mL bacteria, 0.5 mW/cm2 irradiation, and 10−3 mg/mL protein. In the rat model, far ultraviolet-C irradiation at 222 nm significantly decreased intra-abdominal bacteria, reduced blood cytokines (interleukin-1β and interleukin-6), and elevated survival rates from 20% to 60%, compared to lavage alone. The formation of cyclobutane pyrimidine dimers was significantly lower with 222 nm irradiation than with 254 nm, suggesting reduced DNA damage. These findings indicate that far ultraviolet-C irradiation at 222 nm, when combined with lavage, represents a promising therapeutic strategy for bacterial peritonitis, providing effective bacterial reduction and a favorable safety profile. Further research is needed to verify these findings and investigate long-term safety and potential clinical applications.

Investigating the mechanistic role of oxidative stress in brain–gut axis disruption in rat model

Investigating the mechanistic role of oxidative stress in brain–gut axis disruption in rat model

Why we are all lab rats in the digital world

Why we are all lab rats in the digital world

Aromatherapy was used to explore the sedative and hypnotic effects of Moringa seed essential oil on insomnia rats

AbstractMoringa is a type of plant that is used both for medicinal and food. Moringa seed (MS) are rich in volatile oil and have initially been employed to treat diseases of the nervous system. Insomnia, a prevalent neurological disorder, has led to this study's aim: to extract the essential oil from MS and analyze its potential to improve sleep. This study utilized petroleum ether for the thermal extraction of the essential oil from MS, which was then subjected to compositional analysis using Gas Chromatograph Mass Spectrometer (GC–MS). P‐chlorophenyl alanine (PCPA) was used to induce an insomnia model in Sprague–Dawley (SD) rats. Following the successful establishment of the model, the MS essential oil was administered at concentrations of 10%, 5%, and 2.5% to investigate its sedative and hypnotic effects. The efficacy of the MS essential oil was assessed by observing the general condition of rats in each group, conducting an open field test, a pentobarbital sodium righting test, and measuring the serum 5‐HT (5‐hydroxytryptamine) levels and hypothalamic GABA (γ‐aminobutyric acid) content. GC–MS analysis of the MS essential oil revealed a rich composition, including oleic acid, palmitoleic acid, stigmasterol, and γ‐stigmasterol, among other substances. Through the assessment of the rats' general condition, behavioral tests, and blood biochemical assays, it was inferred that MS essential oil aromatherapy can reduce the rat's locomotor activity, increase their interest in activity and exploration, enhance the serum 5‐HT levels, and elevate hypothalamic GABA content. Consequently, it can be concluded that MS essential oil has a sedative and hypnotic effect.

Effect of Different Rates of Rambutan Peel Extract on Visfatin and Cardiac Troponin I Response in Type 2 Diabetic Rats Induced with Streptozotocin

Background: The aim of this study was to investigate the effects of STZ (Streptozotocin) and Rambutan peel extract (RPE) on serum visfatin and cardiac response in experimental Type 2 diabetic rats. Methods: In this study, 64 adult male Wistar albino rats, aged between 8-10 weeks, were used. 8 groups were randomly selected, each containing 8 rats as Control (C), R100 (RPE 100 mg/kg group given with oral gavage route of administration (OGRA), R200 (RPE 200 mg/kg group given with OGRA), R300 (RPE 300 mg/kg group given with OGRA); Diabetes Control (DC): STZ 50 mg/kg i.p administered group, DR100 (D+100 mg/kg JPE), DR200 (D+200 mg/kg JPE), DR300 (D+300 mg/kg JPE). The study lasted a total of 31 days, including adaptation (7 days), induction of diabetes (3 days), and trial period (21 days). Blood samples were taken from the tail vein (vena caudalis) of all subjects on days 0 and 21 of the study. Visfatin and cTnI levels in the serum samples were measured and evaluated by ELISA method. Result: While the increase in mean serum visfatin and cTnI levels in diabetic groups was seen mostly in DC groups, the most significant decrease in mean serum visfatin level due to the addition of RPE was determined in DR100 groups (p less than 0.01).As a result, it was concluded that the administration of 100 mg/kg RPE in rats had no adverse effects. It was concluded that RPE, which has a cardioprotective effect by regulating the visfatin response that plays a role in the development of diabetes, may be useful in supporting the impaired cardiovascular system function that occurs in diabetes.

The Impact of the Histone Deacetylase Inhibitor—Sodium Butyrate on Complement-Mediated Synapse Loss in a Rat Model of Neonatal Hypoxia–Ischemia

AbstractPerinatal asphyxia is one of the most important causes of morbidity and mortality in newborns. One of the key pathogenic factors in hypoxic-ischemic (HI) brain injury is the inflammatory reaction including complement system activation. Over-activated complement stimulates cells to release inflammatory molecules and is involved in the post-ischemic degradation of synaptic connections. On the other hand, complement is also involved in regenerative processes. The histone deacetylase inhibitor (HDACi)—sodium butyrate (SB)—provides reduction of inflammation by decreasing the expression of the proinflammatory factors. The main purpose of this study was to examine the effect of SB treatment on complement activation and synapse elimination after HI. Neonatal HI was induced in Wistar rats pups by unilateral ligation of the common carotid artery followed by 60-min hypoxia (7.6% O2). SB (300 mg/kg) was administered on a 5-day regimen. Our study has shown decreased levels of synapsin I, synaptophysin, and PSD-95 in the hypoxic-ischemic hemisphere, indicating synaptic loss after neonatal HI. Transmission electron microscopy revealed injury of the synaptic structures in the brain after HI. SB treatment increased the level of the synaptic proteins, improved tissue ultrastructure, and reduced degradation of the synapses. Neonatal HI induced mRNA expression of the complement C1q, C3, C5, and C9, and their receptors C3aR and C5aR. The effect of SB was different depending on the time after induction of hypoxic-ischemic damage. Our study demonstrated that neuroprotective effect of SB may be related to the modulation of complement activity after HI brain injury.

Neuroprotective Effects of Ethanol Extract Polyscias guilfoylei (EEPG) Against Glutamate Induced Neurotoxicity in HT22 Cells

Oxidative stress induced by glutamate is a significant contributor to neuronal cell damage and can lead to neurodegenerative diseases such as Alzheimer’s, Huntington’s, and ischemic brain injury. At the cellular level, oxidative stress increases Ca2+ ion influx and reactive oxygen species (ROS), which activate the MAPK signaling pathway. Additionally, the generation of ROS causes mitochondrial dysfunction, triggering apoptosis by promoting the translocation of AIF to the nucleus from the mitochondria. The neuroprotective potential of Polyscias guilfoylei has not yet been reported. Therefore, in this study, the ethanol extract of Polyscias guilfoylei (EEPG) was examined for its protective effect against oxidative cell damage caused by glutamate in neuronal cells. EEPG treatment increased the viability of HT22 cells exposed to high concentrations of glutamate. Cellular Ca2+ ion influx and ROS generation decreased with EEPG treatment in glutamate-treated HT22 cells. EEPG treatment inhibited MAPK activation and AIF nuclear translocation. In an in vivo study, EEPG attenuated brain cell death in an ischemic brain injury rat model. This study demonstrates the potential therapeutic effects of Polyscias guilfoylei in the treatment of ischemic brain injury.

Abstract 4138674: Long-acting CRF2 receptor agonist, COR-1389, improves cardiopulmonary function in the rat model of Sugen plus hypoxia-induced pulmonary hypertension and right heart failure

Introduction: Urocortin-2 (UCN-2), a peptide which is part of the corticotropin-releasing factor (CRF) family, functions as an autocrine and paracrine factor, exerting its effects on cardiac and pulmonary function through agonism of CRF2 receptors. Although acute administration of UCN-2 has shown promise by improving heart and lung function in conditions like heart failure (HF) and pulmonary hypertension (PH), its limited stability impedes its chronic therapeutic use. Hypothesis: In this study, we explored the efficacy of COR-1389, a potent, selective and long-acting CRF2 agonist peptide, in the Sugen 5416 (VEGFR2 inhibitor, Su) combined with hypoxia (Hx) rat model of PH and right heart failure (RHF). Methods: To this aim, male adult Sprague Dawley rats were divided into three groups: Control rats (normoxia) were compared with rats injected subcutaneously with 20 mg/kg Sugen 5416 and exposed to chronic hypoxia for 3 weeks, followed by 2 weeks of normoxia. At 5 weeks, control rats and one SuHx group received subcutaneously vehicle (control and SuHx), while the third group received COR-1389 at a dose of 100 μg/kg every 4 days subcutaneously for 3 weeks (SuHx + COR-1389). At 8 weeks, cardiac and pulmonary hemodynamic functions of the three groups were evaluated using echocardiography and right heart catheterization, and heart and lung tissue were evaluated by histology and immunohistochemistry. Results: Compared to controls (n=10), SuHx exhibited increased mean pulmonary arterial pressure (mPAP), right ventricle (RV) hypertrophy (Fulton Index/body weight), muscularization of distal pulmonary arteries, RV fibrosis and cardiomyocyte hypertrophy, alongside reduced RV systolic function (Tricuspid Annular Plane Systolic Excursion, TAPSE) and cardiac output (CO). Conversely, compared to the SuHx + vehicle group (n=11), curative treatment with COR-1389 for 3 weeks in SuHx rats (n=13) led to enhanced RV systolic function (TAPSE) and CO, together with reductions in mPAP, RV hypertrophy, muscularization of pulmonary arteries, RV fibrosis and cardiomyocyte hypertrophy. Systolic blood pressure remained unchanged across all groups. Conclusion: These findings indicate that COR-1389 ameliorates the deteriorating cardiopulmonary parameters observed in the SuHx model and represents a promising approach for the treatment of PH and RHF.

Abstract 4123631: Significance of collagen triple helix repeat-containing protein 1 as a right ventricular biomarker in pulmonary hypertension

Background: Right ventricular failure is a major prognostic determinant of pulmonary hypertension and progresses with myocardial fibrosis. Extracellular matrix proteins play a major role in myocardial fibrosis. Right ventricular biomarkers for right ventricular function and fibrosis are poorly examined in pulmonary hypertension. This study investigated the significance of collagen triple helix repeat-containing protein 1 (CTHRC1), one of the extracellular matrix proteins, as a right ventricular biomarker. Methods and Results: A monocrotaline-induced pulmonary hypertension rat model was used in this study. CTHRC1 expression in the right ventricle was higher in rats with monocrotaline-induced pulmonary hypertension than in controls. CTHRC1 was associated with fibrosis in the rat's right ventricle. Next, human circulating CTHRC1 levels were evaluated in controls (n = 20), pulmonary arterial hypertension (PAH, n = 46), and chronic thromboembolic pulmonary hypertension (CTEPH) patients (n = 64). Human circulating CTHRC1 levels were higher in PAH (P = 0.006) and CTEPH patients (P = 0.011) than in controls (Figure). Human circulating CTHRC levels were correlated with tricuspid lateral annular peak systolic velocity (R = -0.213, P = 0.029), right ventricular fractional area change (R = -0.225, P = 0.017), and right ventricular global longitudinal strain evaluated by magnetic resonance imaging (R = 0.429, P = 0.009). In addition, human circulating CTHRC1 levels were decreased after balloon pulmonary angioplasty (P < 0.001) in CTEPH patients. Conclusions: CTHRC1 could be a novel biomarker associated with right ventricular failure and fibrosis in pulmonary hypertension patients.

Amelioration of propionic acid‐induced autism‐like behaviors in rats by fenofibrate: A focus on reduction of brain galectin‐3 levels

AbstractIntroductionAutism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interactions and repetitive behaviors. This study examines the effects of fenofibrate on a propionic acid (PPA)‐induced rat model of ASD, focusing on behavioral changes, inflammatory markers, and histological findings.Materials and MethodsThirty male Wistar rats were divided into three groups: a control group, a group receiving PPA and saline, and a group treated with PPA and fenofibrate for 15 days. Behavioral assessments, including the three‐chamber sociability test, open‐field test, and passive avoidance learning, were conducted. Biochemical analyses measured TNF‐α, NGF, IL‐17, IL‐2, and galectin‐3 levels in brain tissues. Histological evaluations focused on Purkinje neuron counts in the cerebellum and neuronal changes in the CA1 and CA3 regions of the hippocampus, along with glial fibrillary acidic protein (GFAP) levels.ResultsFenofibrate treatment significantly improved behavioral outcomes, reducing autism‐like behaviors compared to the PPA/saline group. Biochemically, the PPA/saline group showed elevated levels of malondialdehyde, TNF‐α, IL‐2, IL‐17, and galectin‐3, which were reduced following fenofibrate treatment. Histologically, the PPA/saline group exhibited fewer, dysmorphic Purkinje neurons and increased glial activity in the CA1 region, both of which were ameliorated by fenofibrate treatment.ConclusionFenofibrate shows promise in mitigating autism‐like behaviors in a rat model of ASD, likely due to its antioxidative and neuroprotective properties, which contribute to preserving neuronal integrity and reducing inflammation.

Abstract 4137364: Sex differences in the right ventricle in the Sugen-Hypoxia rat model of pulmonary arterial hypertension

Background: An unexplained estrogen puzzle exists in pulmonary arterial hypertension (PAH): PAH occurs ~4 fold more frequently in women than men; however, women with PAH have better right ventricular (RV) function and survival than the men. Sex differences and the associated mechanism in RV in PAH are not well understood. Aim: To characterize sex differences in RV function and structure in PAH. Methods: Sprague-Dawley rats were injected with Sugen (SU5416, 25mg/kg), and subjected to 3 weeks of hypoxia, followed by 5 weeks of normoxia. Control rats received vehicle and stayed in normoxia for up to 8 weeks. RV pressure-volume, mitochondrial properties, weight, myocyte size, cell proliferation, and interstitial and perivascular (right coronary arteries, RCA) fibrosis were obtained. Results: Sugen-Hypoxia (SuHx) caused significant increases in RV systolic pressure (RVSP) and effective arterial elastance (Ea) in both sexes (P<0.05), but caused slightly greater increase in RV end-systolic elastance (Ees) in females vs males, leading to a preserved RV-pulmonary artery coupling (Ees/Ea) in females and a significant decrease in Ees/Ea in males (P<0.05). SuHx caused a significant increase in RV diastolic pressure only in males (P<0.05), which is associated with significantly higher amount of RV interstitial fibrosis in males vs females. In addition, SuHx caused significant increase in cell proliferation in both sexes (P<0.05) though with slightly greater in crease in males, which is well correlated with RV interstitial fibrosis. Whilst there was no sex difference in RV hypertrophy in SuHx rats as indicated by both fulton index and myocyte size, female RV had smaller myocytes than males at baseline, indicating a greater increase in myocyte size in response to SuHx. Finally, there was a significant increase in RCA fibrosis in male SuHx rats (P<0.05) but not in females, potentially leading to a greater degree of ischemia in male SuHx RV, and this is consistent with impaired mitochondrial properties (decreased mitochondrial fusion, membrane potential an superoxide) in male SuHx rat RV (P<0.05) but preserved mitochoindrial properties in females. Conclusions: SuHx resulted in similar level of RV afterload in both sexes, but compared to males, RV in females responded differently in both function (Ees and mitochondrial properties) and structure (myocyte size and fibrosis). Future studies on the associated mechanism are needed to gain therapeutic insight for RV in PAH.

Abstract 4117256: EFFECT OF CORONARY MICROEMBOLIZATION ON AUTOPHAGY-RELATED MICRORNA AND PROTEIN PATHWAYS STUDY

Background: Coronary microembolization (CME) commonly occurs during PCI in acute coronary syndrome, leading to myocardial damage. The purpose of this study is to explore the effects of CME on autophagy-related microRNAs and protein pathways, and to identify possible mechanisms of myocardial injury caused by CME. Methods: This study randomly divided rats into 6 groups: sham and CME1h, 3h, 6h, 9h, 12h groups. A rat model of CME was established by injecting autologous microthrombi into the left ventricle. Echocardiography and HE staining were performed to evaluate myocardial infarct size in each group. The expression of microRNA-144-3p and microRNA-214-3p, LC3-II, p62/SQSTM1, phosphatase, and PTEN was detected. Results: Compared with the sham group, LVEF and LVFS decreased,LVESD increased (P<0.05) in the CME3h, 6h, 9h, and 12h groups,the myocardial infarct area significantly increased in the CME6h group (P<0.05). The expression of microRNA-144-3p and microRNA-214-3p in myocardial tissue increased after CME, reaching a peak at 1h (P<0.05); LC3II decreased at CME1h (P<0.05) and significantly increased in the CME6h group (P<0.05). p62/SQSTM1 increased at CME1h (P<0.05) and then gradually decreased, while PTEN increased after CME3h (all P<0.05), with a peak at 6h. Conclusion: Autophagy showed dynamic changes after CME, suggesting that enhanced autophagy aggravates myocardial damage after CME. Related microRNAs and PTEN are involved in the regulation of autophagy after CME.

ApoEVs Transfer Mitochondrial Component to Modulate Macrophages in Periodontal Regeneration

ABSTRACTObjectiveMacrophages are key players in the host immune response to periodontal pathogens and tissue repair. The aim of this study was to explore the potential of apoptotic cell‐derived extracellular vesicles (ApoEVs) in modulating the mitochondrial function of macrophages as a mean to enhance periodontal tissue regeneration.Subjects and MethodsApoEVs were extracted from periodontal ligament stem cells (PDLSCs) and characterized to observe their effects on macrophage function. In vivo experiments, ApoEVs were mixed with hyaluronic acid and injected into the periodontal pockets of rats with periodontitis to observe their impact on periodontal tissue regeneration and the immune microenvironment. Functional assays were conducted to confirm whether ApoEVs contained mitochondrial components and which specific components were transferred to regulate macrophage function.ResultsThe experimental findings showed that treatment of ApoEVs efficiently restored the homeostasis of macrophage and improved tissue regeneration in a periodontitis rat model. Mechanism investigation demonstrated that the efferocytosis of ApoEVs resulted in the transfer of mitochondrial components from PDLSCs to macrophage. The increased mitochondrial components within macrophages improved mitochondrial function and polarization of macrophages towards the anti‐inflammatory M2 phenotype, resulting in the improvement of inflammatory environment in periodontal tissues.ConclusionApoEVs can transfer mtDNA to enhance mitochondrial function in macrophages, fostering their transition to an anti‐inflammatory phenotype. Ultimately, this process improves the immune microenvironment in periodontitis and promotes periodontal tissue regeneration.

KDM4A facilitates neuropathic pain and microglial M1 polarization by regulating BDNF in a rat model of brachial plexus avulsion

BackgroundMany patients with brachial plexus avulsion (BPA) suffer from neuropathic pain, but the mechanism remains elusive. Modifications of histones, the proteins responsible for organizing DNA, may play an important role...

Intergenerational crosstalk of brain-gut axis in parental Nd2O3 exposure-induced offspring neurotoxicity and cognitive dysfunction: a mechanistic study

IntroductionRare earth elements (REEs) are widely used in plenty of fields. REEs have significant neurotoxicity and it may adversely affect the development of cognitive. For example, neodymium will causing neurological damage through penetrate the blood–brain barrier (BBB). However, whether it disrupts the balance of brain-gut axis (BGA) crosstalk and affects the intestinal microecology disorder of host is still unclear. This study investigated the neural damage on children caused by maternal exposure to Neodymium oxide (Nd2O3) during pregnancy, and its involved mechanism of BGA injury.MethodsWe used rat model to investigated the mechanisms of the offspring’s neural damage that Nd2O3 exposure in pregnancy. To verify the neural damage of offspring rats, we examed BBB-related factors, such like glutamate and ROS levels in brain tissue, behavioral tests, hippocampal and cortical damage, as well as changes in gut microbiota, intestinal mucosal barrier, and SCFAs in the intestine. Also, we observed some specific indicators of intestinal immune barrier function and gut nerve-related indicators.ResultsMaternal Nd2O3 exposure reduced the content of offspring tight junction proteins, increased BBB permeability, leading to Nd accumulation and brain tissue inflammation, affecting offspring’s neural development and weakening their spatial learning ability. Nd2O3 also disrupted BBB integrity by regulating SCFAs and BGA. Probiotic intervention in the offspring rats exposed to 2% Nd2O3 showed significant recovery of inflammation in both brain and colon tissues, and reduced BBB permeability.ConclusionMaternal exposure to Nd2O3 affects the offspring’s BGA, targeting brain and colon tissues, increasing BBB permeability, affecting neural development, causing damage to the intestinal mucosa, and impacting children’s gut development. Probiotics can alleviate these effects. These findings provide valuable insights into understanding the neurodevelopmental and intestinal developmental toxicity of Nd2O3 and its prevention and treatment. It also calls for a comprehensive assessment of the health risks of susceptible populations to Nd2O3, such as pregnant women. It may providing theoretical basis for preventing and controlling neodymium-induced harm in children by examing the repair mechanism of the damage through probiotic intervention.

Vancomycin-induced acute kidney injury in rats: beneficial effects deriving from the co-administration of tadalafil or vitamin C

Background: Vancomycin (VAN) is widely employed in clinical settings for the treatment of severe infections attributable to multi-resistant bacteria, with a notable emphasis on Gram-positive strains. However, its therapeutic usage is significantly hampered by the potential for acute kidney injury (AKI); specifically, the nephrotoxic effects it can exert. In controlled experimental studies, the intraperitoneal (i.p.) administration of VAN at a dose of 400 mg/kg/day over a consecutive seven-day period has been shown to induce considerable AKI in rats. In addressing this concern, vitamin C (VC), recognized traditionally for its antioxidant properties, has been utilized to mitigate various forms of organ damage and inflammatory responses, primarily by diminishing oxidative stress and attenuating inflammation. Concurrently, tadalafil (TAD), a phosphodiesterase type-5 inhibitor commonly associated with the treatment of erectile dysfunction, is also noted for its beneficial anti-inflammatory and antioxidant effects, alongside vasodilatory properties. Aim: This study was designed in order to investigate the protective capabilities of TAD or VC against the VAN-induced nephrotoxic effects in a rat model of AKI. Methodology: A total of 24 male albino Wistar rats were allocated into four distinct groups for the purpose of comparative analysis. Following treatment, both kidney and blood samples were obtained for further evaluation. The study randomized the rats into four categories: group 1 served as the control group, group 2 received VAN at a dosage of 400 mg/kg (via an i.p. injection on a daily basis), group 3 was administered VAN (400 mg/kg; i.p., daily) in conjunction with TAD at a dose of 5 mg/kg daily, and group 4 was given VAN (400 mg/kg; i.p., daily) alongside VC at a dosage of 200 mg/kg daily. Results: Evaluations included the measurement of renal function indicators such as the serum levels of urea, of creatinine, and the creatinine clearance. Additionally, the analysis involved the assessment of antioxidant markers in renal tissue homogenates, including malondialdehyde (MDA), glutathione, and superoxide dismutase. To further elucidate the inflammatory response, indices such as the levels of the tumor necrosis factor-alpha, the interleukins (IL)-1β and IL-6, and the nuclear factor-κB were evaluated within the renal tissue homogenate samples of the studied rats. The administration of VAN resulted in a marked elevation of renal biomarkers and inflammatory indices, alongside a significant reduction in antioxidant levels, with an exception for MDA (which exhibited increased levels); these changes reached statistical significance (p<0.05) when measured against the control group. In contrast, the supplementation with TAD or VC was effective in significantly lowering the serum levels of both renal and inflammatory indicators when compared to the group treated solely with VAN. Furthermore, antioxidant measurements improved, alongside a reduction in MDA levels, thereby demonstrating significant differences (p<0.05). Conclusion: The findings of this study reveal that both TAD and VC provide a degree of renal protection against the VAN-induced damage by enhancing kidney function markers and, concurrently, lessening oxidative stress and inflammatory responses associated with nephrotoxicity.

Abstract 4139169: Treatment with methotrexate associated with LDL-like nanoparticles prevents the development of left ventricular fibrosis in a spontaneously hypertensive rat model

Introduction: Systemic arterial hypertension (SAH) can lead to left ventricle (LV) fibrosis and ventricular dysfunction. Methotrexate (MTX) associated with lipid nanoparticles (LDE) increases the cellular uptake of MTX by ninety-fold, which leads to therapeutic efficacy and reduces drug toxicity. Previously, treatment of rats with myocardial infarction with LDE-MTX decreased LV fibrosis and prevented ventricular dysfunction. The aim was to test LDE-MTX to preclude the development of cardiac damages caused by hypertension in spontaneously hypertensive rats (SHR). Methods: Twenty-four male rats with six-week-old were allocated in 3 groups: Control (CT): Wistar-Kyoto rats injected with saline; SHR: treated with LDE only and SHR-LDE-MTX: treated with LDE-MTX (1mg/Kg/week, I.P.). After 20 weeks of treatment, echocardiography, morphometry and protein expression were performed in the LV. The data were analyzed by ANOVA with Turkey’s post-test or Kruskal-Wallis test with Dunn's post-test. Linear regression was used to evaluate potential relationships. Results: Compared to CT, the two SHR groups showed dilation (increase in systolic and diastolic diameter); hypertrophy (increased thickness of the posterior wall) and systolic dysfunction (decreased ejection and shortening fractions). Furthermore, the SHR group showed increased LV fibrosis in both the interstitial region and the papillary muscle, possibly resulting from increased of type I collagen content. Treatment of SHR with LDE-MTX had no effect on LV dilation, hypertrophy or systolic dysfunction. However, LDE-MTX decreased LV fibrosis of the interstitial region and the papillary muscle. In addition, LDE-MTX increased the expression of MMP-2, and increased the bioavailability of intracellular adenosine, via increased expression of the adenosine A3 receptor. There was a negative correlation between the expression of the adenosine A3 receptor with interstitial fibrosis (r2=-0.31, p=0.03) and papillary muscle (r2=-0.47, p=0.03), indicating that the increased bioavailability of intracellular adenosine also contributed to the decrease in LV fibrosis in SHR. Conclusion: In SHR, treatment with LDE-MTX reduced LV fibrosis, possibly by modulating MMP-2 expression and increasing the bioavailability of intracellular adenosine, via the adenosine A3 receptor. These results suggest a therapeutic role for LDE-MTX in patients with LV fibrosis and heart failure caused by SAH, to be explored in future clinical studies.

Abstract 4137688: Inhibition of Cardiac Fibrosis and Pro-Fibrotic Collagen Hormone Endotrophin by VS-041, a Novel Drug Candidate for Heart Failure with Preserved Ejection Fraction

Introduction: Endotrophin, a collagen type VI–derived signaling peptide, has been linked to cardiac metabolic dysregulation, inflammation, and fibrosis. Several matrix metalloproteinases (MMPs), incl. MMP2 and MMP9, have been shown to cleave collagen 6A3 and release endotrophin. Baseline plasma endotrophin levels in heart failure with preserved ejection fraction (HFpEF) patients were shown to be strongly and independently associated with increased risk of poor outcomes (death or HF-admissions). VS-041 is a novel drug candidate for HFpEF that inhibits key MMPs implicated in cardiac fibrosis and diastolic dysfunction. Previously, VS-041 demonstrated robust efficacy in the Dahl Salt Sensitive rat model of hypertension and HFpEF, improving diastolic function and dose-proportionally reducing left ventricle (LV) fibrosis. Hypothesis: Inhibition of endotrophin release by VS-041 could contribute to its anti-fibrotic mechanism and serve as a potential biomarker of MMP inhibition (target engagement) in patients. Methods and Results: The effect of VS-041 on production of endotrophin was investigated in a “Scar-in-a-Jar” model using primary human cardiac fibroblasts isolated from adult healthy ventricles. Fibroblasts were treated with 10 ng/mL platelet-derived growth factor (PDGF) AB in the presence of 0.03, 0.3, or 3 µM VS-041, or DMSO control. The concentration of endotrophin in the medium was assessed via the ELISA nordicPRO-C6 TM (Nordic Bioscience A/S). After 4 days of treatment, VS-041 at 0.3 µM and 3 µM significantly inhibited PDGF AB-stimulated production of endotrophin. Cumulative inhibitory effects of VS-041 could still be observed after 12 days of culture. The antifibrotic activity of VS-041 was also tested in a model of extensive cardiac fibrosis in 16-months old C57BL/6 mice exacerbated by angiotensin II infusion at 1 mg/kg/day for 28 days. Oral treatment with VS-041 at 75 mg/kg BID resulted in a 62% reduction (p<0.01) of LV fibrosis as assessed by morphometry of Masson trichrome stained sections. VS-041 also improved the diastolic echocardiography parameters IVRT and E/a ratio. Conclusions: The production of endotrophin by fibroblasts is diminished by VS-041 and, therefore, its plasma levels could be explored as a biomarker of in vivo MMP inhibition by VS-041. Additionally, the inhibition of endotrophin release by VS-041 could be causatively linked to reduction of cardiac fibrosis and potentially translate into improved clinical outcomes in HFpEF patients.

Abstract 4138716: A novel Urocortin-2 analog COR-1167 corrects cardiac and renal dysfunction on top of Empagliflozin in a rat model of acute decompensated heart failure

Introduction: Urocortin-2 (UCN-2) is a peptide belonging to the corticotropin-releasing factor family that has cardiovascular, renal, metabolic and anti-inflammatory actions and improves cardiac function in human heart failure (HF) and cardiorenal dysfunction in chronic HF models. However, UCN-2 has a short half-life and intravenous delivery limits its therapeutic use. COR-1167 was discovered as a stable UCN-2 analog with qd pharmacological effects when injected subcutaneously. Hypothesis: Whether COR-1167 exerts chronic cardiorenal protection in Acute Decompensated HF (ADHF) is unknown, and in particular on background of SGLT2 inhibition, therefore both treatments were tested in a rat model of ADHF. Methods: Rats had coronary artery ligation to induce MI and a reduced ejection fraction phenotype. Three months later, rats were treated with vehicle or Empagliflozin (Empa) at 10 mg/kg/day PO. One month after starting Empa, two acute decompensation events were induced by administrating NaCl solution (1.8 g/kg, PO) on Day 0 and Day 14. Empa treated ADHF rats received vehicle or COR-1167 (3 µg/kg/day) by SC injections starting at 12 hours after the first decompensation and all treatments continued for 14 days. The groups were ADHF, ADHF + Empa and ADHF + Empa + COR-1167 (n=7-10/group). Left ventricular (LV) hemodynamics (cardiac catheters), cardiac output (echocardiography) and LV tissue perfusion (magnetic resonance imaging), cardiac mitochondrial coupling and ATP production (Seahorse) were measured 1 day after the second decompensation, while urine volume (uVol) and urine Na + excretion (uNa + ) collected from metabolic cages were analyzed 7 days after the first decompensation. Results: Compared to ADHF control rats, Empa treatment had no effect on systolic blood pressure (SBP), cardiac output (CO), LV end systolic pressure volume relationship (LVESPVR), LV end diastolic pressure volume relationship (LVEDPR), mitochondrial coupling and ATP production, but it increased myocardial perfusion, uVol and uNa + excretion. Compared to ADHF + Empa rats, COR-1167 treatment increased SBP, CO, LVESPVR, myocardial perfusion, mitochondrial coupling and ATP production, uVol, uNa + , while decreasing LVEDPVR. Conclusion: In the setting of ADHF, significant cardiorenal benefits and decongestion occurred when COR-1167 was administered on top of an SGLT2 inhibitor.