Dihydrotanshinone I preconditions myocardium against ischemic injury via PKM2 glutathionylation sensitive to ROS

Blocking the TRAIL-DR5 Pathway Reduces Cardiac Ischemia-Reperfusion Injury by Decreasing Neutrophil Infiltration and Neutrophil Extracellular Traps Formation

PURPOSE

Acute myocardial infarction (AMI) is a leading cause of mortality. Neutrophils penetrate injured heart tissue during AMI or ischemia-reperfusion (I/R) injury and produce inflammatory factors, chemokines, and extracellular traps that exacerbate heart injury. Inhibition of the TRAIL-DR5 pathway has been demonstrated to alleviate cardiac ischemia-reperfusion injury in a leukocyte-dependent manner. However, it remains unknown whether TRAIL-DR5 signaling is involved in regulating neutrophil extracellular traps (NETs) release.

METHODS

This study used various models to examine the effects of activating the TRAIL-DR5 pathway with soluble mouse TRAIL protein and inhibiting the TRAIL-DR5 signaling pathway using DR5 knockout mice or mDR5-Fc fusion protein on NETs formation and cardiac injury. The models used included a co-culture model involving bone marrow-derived neutrophils and primary cardiomyocytes and a model of myocardial I/R in mice.

RESULTS

NETs formation is suppressed by TRAIL-DR5 signaling pathway inhibition, which can lessen cardiac I/R injury. This intervention reduces the release of adhesion molecules and chemokines, resulting in decreased neutrophil infiltration and inhibiting NETs production by downregulating PAD4 in neutrophils.

CONCLUSION

This work clarifies how the TRAIL-DR5 signaling pathway regulates the neutrophil response during myocardial I/R damage, thereby providing a scientific basis for therapeutic intervention targeting the TRAIL-DR5 signaling pathway in myocardial infarction.

Cardioprotective potential of compound 3K, a selective PKM2 inhibitor in isoproterenol-induced acute myocardial infarction: A mechanistic study

Myocardial infarction (MI) or heart attack arises from acute or chronic prolonged ischemic conditions in the myocardium. Although several risk factors are associated with MI pathophysiology, one of the risk factors is an imbalance in the oxygen supply. The current available MI therapies are still inadequate due to the complexity of MI pathophysiology. Pyruvate kinase M2 (PKM2) has been implicated in numerous CVDs pathologies. However, the effect of specific pharmacological intervention targeting PKM2 has not been studied in MI. Therefore, in this study, we explored the effect of compound 3K, a PKM2-specific inhibitor, in isoproterenol-induced acute MI model. In this study, in order to induce MI in rats, isoproterenol (ISO) was administered at a dose of 100 mg/kg over two days at an interval of 24 h. Specific PKM2 inhibitor, compound 3K (2 and 4 mg/kg), was administered in MI rats to investigate its cardioprotective potential. After the last administration of compound 3K, ECG and hemodynamic parameters were recorded using a PV-loop system. Cardiac histology, western blotting, and plasmatic cardiac damage markers were evaluated to elucidate the underlying mechanisms. Treatment of compound 3K significantly reduced ISO-induced alterations in ECG, ventricular functions, cardiac damage, infarct size, and cardiac fibrosis. Compound 3K treatment produced significant increase in PKM1 expression and decrease in PKM2 expression. In addition, HIF-1α, caspase-3, c-Myc, and PTBP1 expression were also reduced after compound 3K treatment. This study demonstrates the cardioprotective potential of compound 3K in MI, and its mechanisms of cardioprotective action.

Lagopsis supina ameliorates myocardial ischemia injury by regulating angiogenesis, thrombosis, inflammation, and energy metabolism through VEGF, ROS and HMGB1 signaling pathways in rats

BACKGROUND

Lagopsis supina (Steph. ex. Willd.) Ikonn.-Gal. is an important traditional Chinese medicine used to treat various ailments. However, its impact on myocardial ischemia (MI) injury remains unknown.

PURPOSE

This research aimed to reveal the therapeutic effect, potential mechanism, and metabolomics of L. supina against MI injury in rats.

METHODS

The therapeutic effects of the ethanolic extract of L. supina (LS) and its four fractions (LSA∼D) on a left anterior descending (LAD) artery occlusion-induced MI model rat were explored. The pharmacodynamics including myocardial infraction area, myocardial tissue pathology and apoptosis, and serum biochemical parameters (CK, CK-MB, CTn-T, SOD, ET-1, NO, eNOS, VEGF, TXB2, 6-keto-PGF1α, TNF-α, IL-6, and CRP) were evaluated. The 24 related protein expressions were detected using western blotting assay. Simultaneously, the qualitative and quantitative analyses of microporous adsorption resin with 30% (LSC) and 60% (LSD) aqueous ethanol fractions were performed using UHPLC-MS and HPLC. Moreover, the serum metabolomics analysis of rats was profiled using UHPLC-MS.

RESULTS

LS exerted remarkable alleviating effect on MI in rats. Importantly, LSC and LSD, two effective fractions of LS, significantly reduced myocardial infraction area, alleviated myocardial tissue pathology and apoptosis, regulated serum biochemical parameters. Furthermore, LSC and LSD markedly up-regulated the levels of VEGF-A, VEGFR-2, PKC, Bcl-2, Nrf2, HO-1, and thrombin, as well as prominently down-regulated the protein expression of Notch 1, p-PI3K, p-PI3K/PI3K, p-Akt, p-Akt/Akt, Bax, cleaved-caspase-3, cleaved-caspase-3/caspase-3, vWF, p-Erk, p-Erk/Erk, HMGB1, p-p38, p-p38/p38, p-p65, and p-p65/p65. A total of 26 candidate biomarkers were significantly regulated by LSC and LSD and they are mainly involved in amino acid metabolism, glycerophospholipid metabolism, and sphingolipid metabolism. Finally, phenylethanols and flavonoids may be major bio-constituents of LSC and LSD against MI.

CONCLUSIONS

This work, for the first time, demonstrated that L. supina had a significant therapeutic effect on MI in rats. Additionally, LSC and LSD, two bio-fractions from L. supina, exerted their potential to ameliorate MI injury by promoting angiogenesis, inhibiting thrombosis, blocking inflammation, and facilitating energy metabolism through promotion of VEGF pathway, as well as suppression of ROS and HMGB1 pathways in rats. These findings suggest that LSC and LSD hold promise as potential therapeutic agents for MI injury in clinical application.

Dihydrotanshinone I attenuates estrogen-deficiency bone loss through RANKL-stimulated NF-κB, ERK and NFATc1 signaling pathways

Postmenopausal osteoporosis, a chronic condition that predominantly affects postmenopausal women, presents a significant impediment to their overall well-being. The condition arises from estrogen deficiency, leading to enhanced osteoclast activity. Salvia miltiorrhiza, a well-established Chinese herbal medicine with a history of clinical use for osteoporosis treatment, contains diverse active constituents that have shown inhibitory effects on osteoclast formation and bone loss. Dihydrotanshinone I (DTI), a phenanthrenonequinone compound derived from the root of Salvia miltiorrhiza, has been identified as a potential therapeutic agent, although its mechanism of action on osteoclasts remains elusive. In this study, we aimed to elucidate the inhibitory potential of DTI on RANKL-induced osteoclastogenesis. We observed the ability of DTI to effectively impede the expression of key osteoclast-specific genes and proteins, as assessed by Real-time PCR and Western Blotting analyses. Mechanistically, DTI exerted its inhibitory effects on osteoclast formation by modulating critical signaling pathways including NF-κB, ERK, and calcium ion signaling. Notably, DTI intervention disrupted the nuclear translocation and subsequent transcriptional activity of the NFATc1, thus providing mechanistic insights into its inhibitory role in osteoclastogenesis. To further assess the therapeutic potential of DTI, we employed an ovariectomized osteoporosis animal model to examine its impact on bone loss. Encouragingly, DTI demonstrated efficacy in mitigating bone loss induced by estrogen deficiency. In conclusion, our investigation elucidates the ability of DTI to regulate multiple signaling pathways activated by RANKL, leading to the inhibition of osteoclast formation and prevention of estrogen-deficiency osteoporosis. Consequently, DTI emerges as a promising candidate for the treatment of osteoporosis.

Recent advances of tanshinone in regulating autophagy for medicinal research

Initially described as an ancient and highly conserved catabolic biofunction, autophagy plays a significant role in disease pathogenesis and progression. As the bioactive ingredient of Salvia miltiorrhiza, tanshinone has recently shown profound effects in alleviating and treating various diseases by regulating autophagy. However, compared to the remarkable achievements in the known pharmacological effects of this traditional Chinese medicine, there is a lack of a concise and comprehensive review deciphering the mechanism by which tanshinone regulates autophagy for medicinal research. In this context, we concisely review the advances of tanshinone in regulating autophagy for medicinal research, including human cancer, the nervous system, and cardiovascular diseases. The pharmacological effects of tanshinone targeting autophagy involve the regulation of autophagy-related proteins, such as Beclin-1, LC3-II, P62, ULK1, Bax, ATG3, ATG5, ATG7, ATG9, and ATG12; the regulation of the PI3K/Akt/mTOR, MEK/ERK/mTOR, Beclin-1-related, and AMPK-related signaling pathways; the accumulation of reactive oxygen species (ROS); and the activation of AMPK. Notably, we found that tanshinone played a dual role in human cancers in an autophagic manner, which may provide a new avenue for potential clinical application. In brief, these findings on autophagic tanshinone and its derivatives provide a new clue for expediting medicinal research related to tanshinone compounds and autophagy.