Inhibition of mTOR by rapamycin does not improve hypoxic pulmonary hypertension-induced right heart failure in old mice

Searching for Old and New Small-Molecule Protein Kinase Inhibitors as Effective Treatments in Pulmonary Hypertension-A Systematic Review

Treatment options for pulmonary arterial hypertension (PAH) have improved substantially in the last 30 years, but there is still a need for novel molecules that can regulate the excessive accumulation of pulmonary artery smooth muscle cells (PASMCs) and consequent vascular remodeling. One set of possible candidates are protein kinases. The study provides an overview of existing preclinical and clinical data regarding small-molecule protein kinase inhibitors in PAH. Online databases were searched from 2001 to 2023 according to PRISMA. The corpus included preclinical studies demonstrating alterations in at least one PH-related parameter following chronic exposure to an individual protein kinase inhibitor, as well as prospective clinical reports including healthy adults or those with PAH, with primary outcomes defined as safety or efficacy of an individual small-molecule protein kinase inhibitor. Several models in preclinical protocols (93 papers) have been proposed for studying small-molecule protein kinase inhibitors in PAH. In total, 51 kinase inhibitors were tested. Meta-analysis of preclinical results demonstrated seralutinib, sorafenib, fasudil hydrochloride, and imatinib had the most comprehensive effects on PH with anti-inflammatory, anti-oxidant, and anti-proliferative potential. Fasudil demonstrated more than 70% animal survival with the longest experimental period, while dasatinib, nintedanib, and (R)-crizotinib could deteriorate PAH. The substances targeting the same kinases often varied considerably in their activity, and such heterogeneity may be due to the variety of causes. Recent studies have addressed the molecules that affect multiple networks such as PDG-FRα/β/CSF1R/c-KIT/BMPR2 or FKBP12/mTOR. They also focus on achieving a satisfactory safety profile using innovative inhalation formulations Many small-molecule protein kinase inhibitors are able to control migration, proliferation and survival in PASMCs in preclinical observations. Standardized animal models can successfully reduce inter-study heterogeneity and thereby facilitate successful identification of candidate drugs for further evaluations.

Systems Pharmacology to Explore the Potential Mechanism of Ginseng Against Heart Failure

The aim of this study is to elucidate the pharmacological mechanism underlying the effects of Ginseng Radix et Rhizoma (ginseng) in heart failure (HF), providing a theoretical foundation for its clinical application. The potential mechanism of ginseng in the context of HF was investigated using systems pharmacology that combined network pharmacology, Gene Expression Omnibus (GEO) analysis, molecular docking, and experimental verification. Network pharmacology was employed to identify drug-disease targets. Core gene targets were subsequently subjected to enrichment analysis by integrating network pharmacology with GEO. Molecular docking was utilized to predict the binding affinities between identified targets and ginseng compounds. Furthermore, the therapeutic efficacy of ginseng was validated in an isoproterenol (ISO)-induced rat model of HF. The modulation of key signaling pathways by ginseng was confirmed through Western blot analysis. A total of 154 potential targets of ginseng in the treatment of HF were identified through network pharmacology analysis. The analysis of GSE71613 revealed that the PI3K-Akt pathway, reactive oxygen species, oxidative phosphorylation, MAPK signaling, and Ras signaling pathways are predominantly associated with patients with HF. By integrating the findings from network pharmacology and GEO analysis, ginsenoside Rg1 and ginsenoside Rb3 were identified as the potential components in ginseng, while FN1 and PRKAA2 were recognized as key targets involved in the PI3K-AKT and AMPK pathways, respectively. Molecular docking analysis revealed a strong affinity between the potential components and the identified core targets. In vivo experiments indicated that the extract of ginseng (EPG) significantly ameliorated ISO-induced cardiac dysfunction by improving cardiac parameters such as cardiac left ventricular internal systolic diameter, left ventricular end-diastolic volume, left ventricular end systolic volume, and left ventricular ejection fraction, while also reducing malondialdehyde production. In addition, EPG was found to enhance superoxide dismutase activity and ATP levels, while concurrently reducing the levels of interleukin (IL)-1β, IL-6, and TNF-α. The extract also reduced myocardial oxygen consumption, inflammatory cell infiltration, and the number of damaged myocardial fibers. Moreover, EPG was observed to upregulate the expression of p-PI3K, p-AKT, p-AMPK, and Bcl-2, while downregulating the expression of p-NFκB, TGF-β, and Bax. The therapeutic effects of ginseng on HF are primarily mediated through the PI3K-Akt and AMPK pathways. Ginsenoside Rg1 and ginsenoside Rb3 have been identified as potential therapeutic agents for HF.

Molecular remodeling in comorbidities associated with heart failure: a current update

Recent advances in genomics and proteomics have helped in understanding the molecular mechanisms and pathways of comorbidities and heart failure. In this narrative review, we reviewed molecular alterations in common comorbidities associated with heart failure such as obesity, diabetes mellitus, systemic hypertension, pulmonary hypertension, coronary artery disease, hypercholesteremia and lipoprotein abnormalities, chronic kidney disease, and atrial fibrillation. We searched the electronic databases, PubMed, Ovid, EMBASE, Google Scholar, CINAHL, and PhysioNet for articles without time restriction. Although the association between comorbidities and heart failure is already well established, recent studies have explored the molecular pathways in much detail. These molecular pathways demonstrate how novels drugs for heart failure works with respect to the pathways associated with comorbidities. Understanding the altered molecular milieu in heart failure and associated comorbidities could help to develop newer medications and targeted therapies that incorporate these molecular alterations as well as key molecular variations across individuals to improve therapeutic outcomes. The molecular alterations described in this study could be targeted for novel and personalized therapeutic approaches in the future. This knowledge is also critical for developing precision medicine strategies to improve the outcomes for patients living with these conditions.

mTOR in the Development of Hypoxic Pulmonary Hypertension Associated with Cardiometabolic Risk Factors

The pathophysiology of pulmonary hypertension is complex and multifactorial. It is a disease characterized by increased pulmonary vascular resistance at the level due to sustained vasoconstriction and remodeling of the pulmonary arteries, which triggers an increase in the mean pulmonary artery pressure and subsequent right ventricular hypertrophy, which in some cases can cause right heart failure. Hypoxic pulmonary hypertension (HPH) is currently classified into Group 3 of the five different groups of pulmonary hypertensions, which are determined according to the cause of the disease. HPH mainly develops as a product of lung diseases, among the most prevalent causes of obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD), or hypobaric hypoxia due to exposure to high altitudes. Additionally, cardiometabolic risk factors converge on molecular mechanisms involving overactivation of the mammalian target of rapamycin (mTOR), which correspond to a central axis in the development of HPH. The aim of this review is to summarize the role of mTOR in the development of HPH associated with metabolic risk factors and its therapeutic alternatives, which will be discussed in this review.

The effects of sodium-glucose cotransporter 2 inhibitors on the 'forgotten' right ventricle

With the progress in diagnosis, treatment and imaging techniques, there is a growing recognition that impaired right ventricular (RV) function profoundly affects the prognosis of patients with heart failure (HF), irrespective of their left ventricular ejection fraction (LVEF). In addition, right HF (RHF) is a common complication associated with various diseases, including congenital heart disease, myocardial infarction (MI), pulmonary arterial hypertension (PAH) and dilated cardiomyopathy (DCM), and it can manifest at any time after left ventricular assist devices (LVADs). The sodium-glucose cotransporter 2 (SGLT2) inhibition by gliflozins has emerged as a cornerstone medicine for managing type 2 diabetes mellitus (T2DM) and HF, with an increasing focus on its potential to enhance RV function. In this review, we aim to present an updated perspective on the pleiotropic effects of gliflozins on the right ventricle and offer insights into the underlying mechanisms. We can ascertain their advantageous impact on the right ventricle by discussing the evidence obtained in animal models and monumental clinical trials. In light of the pathophysiological changes in RHF, we attempt to elucidate crucial mechanisms regarding their beneficial effects, including alleviation of RV overload, reduction of hyperinsulinaemia and inflammatory responses, regulation of nutrient signalling pathways and cellular energy metabolism, inhibition of oxidative stress and myocardial fibrosis, and maintenance of ion balance. Finally, this drug class's potential application and benefits in various clinical settings are described, along with a prospective outlook on future clinical practice and research directions.

Investigating TIP30-Mediated regulation of mTORC1 signaling as a therapeutic strategy for coxsackievirus B3-Induced viral myocarditis

This study aims to elucidate the role of TIP30 (30 KDa HIV-1 TAT-Interacting Protein) in the progression of coxsackievirus B3 (CVB3)-induced viral myocarditis. TIP30 knockout and wildtype mice were intraperitoneally infected with CVB3 and evaluated at day 7 post-infection. HeLa cells were transfected with TIP30 lentiviral particles and subsequently infected with CVB3 to evaluate viral replication, cellular pathogenesis, and mechanistic target of rapamycin complex 1 (mTORC1) signaling. Deletion of the TIP30 gene heightened heart virus titers and mortality rates in mice with CVB3-induced myocarditis, exacerbating cardiac damage and fibrosis, and elevating pro-inflammatory factors level. In vitro experiments demonstrated the modulation of mTORC1 signaling by TIP30 during CVB3 infection in HeLa cells. TIP30 overexpression mitigated CVB3-induced cellular pathogenesis and VP1 expression, with rapamycin, an mTOR1 inhibitor, reversing these effects. These findings suggest TIP30 plays a critical protective role against CVB3-induced myocarditis by regulating mTORC1 signaling.

Transcriptomic profiling highlights cell proliferation in the progression of experimental pulmonary hypertension in rats

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by pulmonary vascular remolding and occlusion, leading to the elevated pulmonary arterial pressures, right ventricular hypertrophy, and eventual heart failure if left untreated. Understanding the molecular mechanisms underlying the development and progression of pulmonary hypertension (PH) is crucial for devising efficient therapeutic approaches for the disease. Lung homogenates were collected weekly and underwent RNA-sequencing in the monocrotaline (MCT)-induced PH rat model to explore genes associated with PH progression. Statistical analyses revealed 1038, 1244, and 3125 significantly altered genes (P < 0.05, abs (log2fold change) > log21.5) between control and MCT-exposed rats during the first, second, and third week, respectively. Pathway enrichment analyses revealed involvement of cell cycle and innate immune system for the upregulated genes, GPCR and VEGF signaling for the downregulated genes. Furthermore, qRT-PCR validated upregulation of representative genes associated with cell cycle including Cdc25c (cell division cycle 25C), Cdc45, Top2a (topoisomerase IIα), Ccna2 (cyclin A2) and Ccnb1 (cyclin B1). Western blot and immunofluorescence analysis confirmed increases in PCNA, Ccna2, Top2a, along with other proliferation markers in the lung tissue of MCT-treated rats. In summary, RNA sequencing data highlights the significance of cell proliferation in progression of rodent PH.

Lycorine ameliorates isoproterenol-induced cardiac dysfunction mainly via inhibiting inflammation, fibrosis, oxidative stress and apoptosis

Alleviating cardiac dysfunction improves the prognosis of heart failure patients. Lycorine is an alkaloid with several beneficial biological properties. Here, we used mice to evaluate the effect of lycorine on cardiac dysfunction elicited by isoproterenol. Mice were divided into four groups: control, lycorine, isoproterenol, and isoproterenol + lycorine. Mice in the combined group were treated daily with 10 mg/kg isoproterenol intraperitoneally for 2 weeks and 5 mg/kg lycorine was given simultaneously intraperitoneally for 4 weeks. Cardiac structure and function were assessed by echocardiography, hematoxylin and eosin staining, and Masson's trichrome staining. Isoproterenol-induced cardiac dysfunction and histopathological injury that was significantly improved by treatment with lycorine. Western blotting and the quantitative real-time polymerase chain reaction were used to explore the molecular mechanisms of these effects. Levels of the inflammatory cytokines, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, were increased by treatment with isoproterenol; these increases were significantly reduced by lycorine, with involvement of the NF-κB signaling pathway. The fibrotic factors, collagen I and collagen III, were increased by isoproterenol and decreased by treatment with lycorine through inhibiting activation of the Smad signaling pathway. In addition, lycorine alleviated oxidative stress as evidenced by a reduction in total reactive oxygen species in the isoproterenol + lycorine group compared to the isoproterenol group. Lycorine exerted an anti-apoptotic effect as evidenced by upregulating Bcl-2 and downregulating Bax. Overall, our findings demonstrate that lycorine protects against cardiac dysfunction induced by isoproterenol by inhibiting inflammation, fibrosis, oxidative stress, and apoptosis.