Ginsenoside Rd promotes omentin secretion in adipose through TBK1-AMPK to improve mitochondrial biogenesis via WNT5A/Ca2+ pathways in heart failure.

Ginsenoside Rd is an active ingredient in Panax ginseng CA Mey and can be absorbed into the adipose tissue. Adipokines play an important role in the treatment of cardiovascular diseases. However, the potential benefit of Rd on heart failure (HF) and the underlying mechanism associated with the crosstalk between adipocytes and cardiomyocytes remains to be illustrated. Here, the results identified that Rd improved cardiac function and inhibited cardiac pathological changes in transverse aortic constriction (TAC), coronary ligation (CAL) and isoproterenol (ISO)-induced HF mice. And Rd promoted the release of omentin from the adipose tissue and up-regulated omentin expression in lipopolysaccharide (LPS)-induced 3T3-L1 adipocytes. Further, Rd could increase TBK1 and AMPK phosphorylation in adipocytes. And also, the TBK1-AMPK signaling pathway regulated the expression of omentin in LPS-induced adipocytes. Moreover, the omentin mRNA expression was significantly decreased by TBK1 knockdown in LPS-induced 3T3-L1 adipocytes. Additionally, molecular docking and SPR analysis confirmed that Rd had a certain binding ability with TBK1, and co-treatment with TBK1 inhibitors or TBK1 knockdown partially abolished the effect of Rd on increasing the omentin expression and the ratio of p-AMPK to AMPK in adipocytes. Moreover, we found that circulating omentin level diminished in the HF patients compared with healthy subjects. Meanwhile, the adipose tissue-specific overexpression of omentin improved cardiac function, reduced myocardial infarct size and ameliorated cardiac pathological features in CAL-induced HF mice. Consistently, exogenous omentin reduced mtROS levels and restored ΔψM to improve oxygen and glucose deprivation (OGD)-induced cardiomyocytes injury. Further, omentin inhibited the WNT5A/Ca2+ signaling pathway and promoted mitochondrial biogenesis function to ameliorate myocardial ischemia injury. However, WNT5A knockdown inhibited the impairment of mitochondrial biogenesis and partially counteracted the cardioprotective effect of omentin in vitro. Therefore, this study indicated that Rd promoted omentin secretion from adipocytes through the TBK1-AMPK pathway to improve mitochondrial biogenesis function via WNT5A/Ca2+ signaling pathway to ameliorate myocardial ischemia injury, which provided a new therapeutic mechanism and potential drugs for the treatment of HF.

Omentin1 ameliorates myocardial ischemia-induced heart failure via SIRT3/FOXO3a-dependent mitochondrial dynamical homeostasis and mitophagy.

BACKGROUND: Adipose tissue-derived adipokines are involved in various crosstalk between adipose tissue and other organs. Omentin1, a novel adipokine, exerts vital roles in the maintenance of body metabolism, insulin resistance and the like. However, the protective effect of omentin1 in myocardial ischemia (MI)-induced heart failure (HF) and its specific mechanism remains unclear and to be elucidated. METHODS: The model of MI-induced HF mice and oxygen glucose deprivation (OGD)-injured cardiomyocytes were performed. Mice with overexpression of omentin1 were constructed by a fat-specific adeno-associated virus (AAV) vector system. RESULTS: We demonstrated that circulating omentin1 level diminished in HF patients compared with healthy subjects. Furthermore, the fat-specific overexpression of omentin1 ameliorated cardiac function, cardiac hypertrophy, infarct size and cardiac pathological features, and also enhanced SIRT3/FOXO3a signaling in HF mice. Additionally, administration with AAV-omentin1 increased mitochondrial fusion and decreased mitochondrial fission in HF mice, as evidenced by up-regulated expression of Mfn2 and OPA1, and downregulation of p-Drp1(Ser616). Then, it also promoted PINK1/Parkin-dependent mitophagy. Simultaneously, treatment with recombinant omentin1 strengthened OGD-injured cardiomyocyte viability, restrained LDH release, and enhanced the mitochondrial accumulation of SIRT3 and nucleus transduction of FOXO3a. Besides, omentin1 also ameliorated unbalanced mitochondrial fusion-fission dynamics and activated mitophagy, thereby, improving the damaged mitochondria morphology and controlling mitochondrial quality in OGD-injured cardiomyocytes. Interestingly, SIRT3 played an important role in the improvement effects of omentin1 on mitochondrial function, unbalanced mitochondrial fusion-fission dynamics and mitophagy. CONCLUSION: Omentin1 improves MI-induced HF and myocardial injury by maintaining mitochondrial dynamical homeostasis and activating mitophagy via upregulation of SIRT3/FOXO3a signaling. This study provides evidence for further application of omentin1 in cardiovascular diseases from the perspective of crosstalk between heart and adipose tissue.

Cardioprotective effect of ginsenoside Rb1 via regulating metabolomics profiling and AMP-activated protein kinase-dependent mitophagy.

Background: Ginsenoside Rb1, a bioactive component isolated from the Panax ginseng, acts as a remedy to prevent myocardial injury. However, it is obscure whether the cardioprotective functions of Rb1 are related to the regulation of endogenous metabolites, and its potential molecular mechanism still needs further clarification, especially from a comprehensive metabolomics profiling perspective. Methods: The mice model of acute myocardial ischemia (AMI) and oxygen glucose deprivation (OGD)-induced cardiomyocytes injury were applied to explore the protective effect and mechanism of Rb1. Meanwhile, the comprehensive metabolomics profiling was conducted by high-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (HPLC-Q/TOF-MS) and a tandem liquid chromatography and mass spectrometry (LC-MS). Results: Rb1 treatment profoundly reduced the infarct size and attenuated myocardial injury. The metabolic network map of 65 differential endogenous metabolites was constructed and provided a new inspiration for the treatment of AMI by Rb1, which was mainly associated with mitophagy. In vivo and in vitro experiments, Rb1 was found to improve mitochondrial morphology, mitochondrial function and promote mitophagy. Interestingly, the mitophagy inhibitor partly attenuated the cardioprotective effect of Rb1. Additionally, Rb1 markedly facilitated the phosphorylation of AMP-activated protein kinase α (AMPKα), and AMPK inhibition partially weakened the role of Rb1 in promoting mitophagy. Conclusions: Ginsenoside Rb1 protects acute myocardial ischemia injury through promoting mitophagy via AMPKα phosphorylation, which might lay the foundation for the further application of Rb1 in cardiovascular diseases.

Ruscogenin Alleviates Myocardial Ischemia-Induced Ferroptosis through the Activation of BCAT1/BCAT2.

Ruscogenin (RUS), a natural steroidal sapogenin, exerts various biological activities. However, its effectiveness for preventing myocardial ischemia (MI) and its molecular mechanisms need further clarification. The model of MI mice and oxygen-glucose deprivation-induced cardiomyocytes injury was performed. RUS significantly alleviated MI, as evidenced by decreased infarct size, ameliorated biochemical indicators and cardiac pathological features, and markedly inhibited ferroptosis by means of the up-regulation of GPX4 and down-regulation of ACSL4 and FLC. Simultaneously, RUS notably mitigated cell injury and oxidative stress, and ameliorated ferroptosis in vitro. Subsequently, HPLC-Q-TOF/MS-based metabolomics identified BCAT1/BCAT2 as possible regulatory enzymes responsible for the cardioprotection of RUS. Importantly, RUS treatment significantly increased the expression of BCAT1 and BCAT2 in MI. Furthermore, we found that BCAT1 or BCAT2 siRNA significantly decreased cell viability, promoted ferroptosis, and increased Keap1 expression, and induced Nrf2 and HO-1 degradation in cardiomyocytes. Conversely, cardiac overexpression of BCAT1 or BCAT2 in MI mice activated the Keap1/Nrf2/HO-1 pathway. Moreover, RUS significantly activated the Keap1/Nrf2/HO-1 pathway in MI, whereas BCAT1 or BCAT2 siRNA partially weakened the protective effects of RUS, suggesting that RUS might suppress myocardial injury through BCAT1 and BCAT2. Overall, this study demonstrated that BCAT1/BCAT2 could alleviate MI-induced ferroptosis through the activation of the Keap1/Nrf2/HO-1 pathway and RUS exerted cardioprotective effects via BCAT1/BCAT2.

[A clinical study on the treatment of mucocele by bleomyin A5 combined with phosphorus-32 colloid].

OBJECTIVE: To evaluate the effect of bleomyin A5 combined with phosphorus-32 colloid in the treatment of mucocele. METHODS: A total of 214 patients divided into three groups, bleomyin A5 (50 cases), phosphorus-32 colloid (50 cases) and bleomyin A5 combined with phosphorus-32 colloid (114 cases). RESULTS: The efficacy of bleomyin A5 group, phosphorus-32 colloid group, and bleomyin A5 combined with phosphorus-32 colloid group was 84% (42/50), 82% (41/50) and 98% (112/114), respectively. There were significant difference in efficacy among the three groups (P < 0.05). The phosphorus-32 colloid group and the bleomyin A5 group had no significant difference in efficacy (P > 0.05). CONCLUSIONS: The independent use of bleomyin A5 and phosphorus-32 colloid is effective, but the combined use of the two methods is more effective.

Solid-state NMR investigation of the buried X-proline peptide bonds of bacteriorhodopsin.

The role of proline residues in the photocycle of bacteriorhodopsin (bR) is addressed using solid-state NMR. (13)C and (15)N chemical shifts from X-Pro peptide bonds in bR are assigned from REDOR difference spectra of pairwise labeled samples, and correlations of chemical shifts with structure are explored in a series of X-Pro model compounds. Results for the three membrane-embedded X-Pro bonds of bR indicate only slight changes in the transition from the resting state of the protein to either the early or late M state of the protonmotive photocycle. These results suggest that the buried prolines serve a principally structural role in bR.

Tryptophan interactions in bacteriorhodopsin: a heteronuclear solid-state NMR study.

The bulky and amphiphilic nature of tryptophan residues makes them particularly interesting components of proteins. In bacteriorhodopsin, four of the eight tryptophan residues are in the active site, forming parts of the retinal binding pocket. In this work, we use solid-state NMR to study the interactions of the tryptophan residues in wild-type bacteriorhodopsin, in the resting state, and in critical intermediates of the proton-motive photocycle. The range of the chemical shifts of the indole nitrogens suggests that all eight of them are hydrogen bonded. Using difference spectroscopy, we isolate several changes in these hydrogen bonds in the early and late M states. As found earlier for the peptide backbone, some perturbations found in the early M state relax in the transition to the late M state while new perturbations arise. Interestingly, Rotational Echo DOuble Resonance (REDOR) difference spectroscopy of [20-13C]retinal,[indole-15N]Trp-bR shows that indole of Trp182 is not involved in the significant hydrogen bond perturbations. We also use REDOR to measure dipolar interactions in [20-13C]retinal,[indole-15N]Trp-bR, and thereby determine the distance between the C20 of retinal and the indole nitrogen of Trp182. The internuclear distance changes only slightly from the light-adapted state (3.36 +/- 0.2 A) to the early M state (3.16 +/- 0.4 A).

Control of the pump cycle in bacteriorhodopsin: mechanisms elucidated by solid-state NMR of the D85N mutant.

By varying the pH, the D85N mutant of bacteriorhodopsin provides models for several photocycle intermediates of the wild-type protein in which D85 is protonated. At pH 10.8, NMR spectra of [zeta-(15)N]lys-, [12-(13)C]retinal-, and [14,15-(13)C]retinal-labeled D85N samples indicate a deprotonated, 13-cis,15-anti chromophore. On the other hand, at neutral pH, the NMR spectra of D85N show a mixture of protonated Schiff base species similar to that seen in the wild-type protein at low pH, and more complex than the two-state mixture of 13-cis,15-syn, and all-trans isomers found in the dark-adapted wild-type protein. These results lead to several conclusions. First, the reversible titration of order in the D85N chromophore indicates that electrostatic interactions have a major influence on events in the active site. More specifically, whereas a straight chromophore is preferred when the Schiff base and residue 85 are oppositely charged, a bent chromophore is found when both the Schiff base and residue 85 are electrically neutral, even in the dark. Thus a "bent" binding pocket is formed without photoisomerization of the chromophore. On the other hand, when photoisomerization from the straight all-trans,15-anti configuration to the bent 13-cis,15-anti does occur, reciprocal thermodynamic linkage dictates that neutralization of the SB and D85 (by proton transfer from the former to the latter) will result. Second, the similarity between the chromophore chemical shifts in D85N at alkaline pH and those found previously in the M(n) intermediate of the wild-type protein indicate that the latter has a thoroughly relaxed chromophore like the subsequent N intermediate. By comparison, indications of L-like distortion are found for the chromophore of the M(o) state. Thus, chromophore strain is released in the M(o)-->M(n) transition, probably coincident with, and perhaps instrumental to, the change in the connectivity of the Schiff base from the extracellular side of the membrane to the cytoplasmic side. Because the nitrogen chemical shifts of the Schiff base indicate interaction with a hydrogen-bond donor in both M states, it is possible that a water molecule travels with the Schiff base as it switches connectivity. If so, the protein is acting as an inward-driven hydroxyl pump (analogous to halorhodopsin) rather than an outward-driven proton pump. Third, the presence of a significant C [double bond] N syn component in D85N at neutral pH suggests that rapid deprotonation of D85 is necessary at the end of the wild-type photocycle to avoid the generation of nonfunctional C [double bond] N syn species.