Long-term risks of cardiovascular death in a population-based cohort of 1,141,675 older patients with cancer.

BACKGROUND: previous studies have focused on the risk of cardiovascular disease (CVD)-related death in individual cancers, adolescents or all cancers. OBJECTIVE: to evaluate the risk of CVD-related death in older patients with cancer. METHODS: older patients with cancer (over 65 years) of 16 cancers diagnosed between 1975 and 2018 were screened out from the Surveillance, Epidemiology and End Results program. The proportion of deaths, competing risk regression models, standardized mortality ratios (SMRs) and absolute excess risks (AERs) were used to assess the risk of CVD-related death. RESULTS: this study included 1,141,675 older patients (median follow-up: 13.5 years). Of the 16 individual cancers, the risk of CVD death exceeded primary neoplasm death in older patients with cancers of the breast, endometrium, vulva, prostate gland, penis and melanoma of the skin over time (high competing risk group). Compared to the general older population, older patients with cancer had higher SMR and AER of CVD-related death (SMR: 1.58-4.23; AER: 21.16-365.89), heart disease-related death (SMR: 1.14-4.16; AER: 16.29-301.68) and cerebrovascular disease-related death (SMR: 1.11-4.66; AER: 3.02-72.43), with the SMR trend varying with CVD-related death competing risk classifications. The risk of CVD-related death in the high-competing risk group was higher than in the low-competing risk group. CONCLUSIONS: for older patients with cancer, six of 16 individual cancers, including breast, endometrium, vulva, prostate gland, penis and melanoma of the skin was at high risk of CVD-related death. Management for long-term cardiovascular risk in older patients with cancer is needed.

Effect of stimuli type on affective memory of patients with different severities of cognitive impairment.

OBJECTIVES: To understand the differences in affective memory performance under different degrees of cognitive impairment, this study recruited older people with different degrees of cognitive impairment, to perform emotion recognition memory tasks. METHODS: Fifty-four elderly participants aged (65-85 years) were recruited. Of these, 18 had mild cognitive impairment, 18 had a mild form of Alzheimer's disease, and the remaining 18 were healthy. Factors such as the different emotional valences (positive, neutral, or negative) and stimulus types (pictures, words, or sounds) were manipulated to explore their influences on the emotion recognition memory of people with different degrees of cognitive impairment. RESULTS: The results showed that people's performance to positive stimuli worsened as their degree of cognitive impairment increased. All participants had difficulty processing memory of affective sound stimuli compared to the other two stimulus types. CONCLUSIONS: The results explain the decline in the cognitive ability process, in affective memory performance, of people with different degrees of cognitive impairment. This abnormal decline on affective memory performance could be an early diagnostic indicator of Alzheimer's disease. The results can hopefully be used as a reference for subsequent research on cognition-related diseases and age-related decline, especially regarding affective memory.

Deficiency of proline/serine-rich coiled-coil protein 1 (PSRC1) accelerates trimethylamine N-oxide-induced atherosclerosis in ApoE-/- mice.

AIMS: The main therapeutic strategies for coronary artery disease (CAD) are mainly based on the correction of abnormal cholesterol levels; however, residual risks remain. The newly proven gut microbial metabolite trimethylamine N-oxide (TMAO) linked with CAD has broadened our horizons. In this study, we determined the role of proline/serine-rich coiled-coil protein 1 (PSRC1) in TMAO-driven atherosclerosis. METHODS AND RESULTS: We first analyzed the levels of TMAO and PSRC1 in patients with or without atherosclerosis with a target LDL-C < 1.8 mmol/L. Plasma TMAO levels were increased and negatively associated with decreased PSRC1 in peripheral blood mononuclear cells. Animals and in vitro studies showed that TMAO inhibited macrophage PSRC1 expression due to DNA hypermethylation of CpG islands. ApoE-/- mice fed a choline-supplemented diet exhibited reduced PSRC1 expression accompanied by increased atherosclerotic lesions and plasma TMAO levels. We further deleted PSRC1 in apoE-/- mice and PSRC1 deficiency significantly accelerated choline-induced atherogenesis, characterized by increased macrophage infiltration, foam cell formation and M1 macrophage polarization. Mechanistically, we overexpressed and knocked out PSRC1 in cultured macrophages to explore the mechanisms underlying TMAO-induced cholesterol accumulation and inflammation. PSRC1 deletion impaired reverse cholesterol transport and enhanced cholesterol uptake and inflammation, while PSRC1 overexpression rescued the proatherogenic phenotype observed in TMAO-stimulated macrophages, which was partially attributed to sulfotransferase 2B1b (SULT2B1b) inhibition. CONCLUSIONS: Herein, clinical data provide evidence that TMAO may participate in the development of CAD beyond well-controlled LDL-C levels. Our work also suggests that PSRC1 is a negative regulator mediating the unfavorable effects of TMAO-containing diets. Therefore, PSRC1 overexpression and reduced choline consumption may further alleviate atherosclerosis.

Limb-Bud and Heart (LBH) Upregulation in Cardiomyocytes under Hypoxia Promotes the Activation of Cardiac Fibroblasts via Exosome Secretion.

The activation of cardiac fibroblasts (CFs) after myocardial infarction (MI) is essential for post-MI infarct healing, during which the regulation of transforming growth factor beta1 (TGF-ß1) signaling is predominant. We have demonstrated that TGF-ß1-mediated upregulation of LBH contributes to post-MI CF activation via modulating αB-crystallin (CRYAB), after being upregulated by TGF-ß1. In this study, the effect of LBH-CRYAB signaling on the cardiac microenvironment via exosome communication and the corresponding mechanisms were investigated. The upregulation of LBH and CRYAB was verified in both cardiomyocytes (CMs) and CFs in hypoxic, post-MI peri-infarct tissues. CM-derived exosomes were isolated and identified, and LBH distribution was elevated in exosomes derived from LBH-upregulated CMs under hypoxia. Treatment with LBH+ exosomes promoted cellular proliferation, differentiation, and epithelial-mesenchymal transition-like processes in CFs. Additionally, in primary LBHKO CFs, western blotting showed that LBH knockout partially inhibited TGF-ß1-induced CF activation, while LBH-CRYAB signaling affected TGF-ß1 expression and secretion through a positive feedback loop. The administration of a Smad3 phosphorylation inhibitor to LBHKO CFs under TGF-ß1 stimulation indicated that Smad3 phosphorylation partially accounted for TGF-ß1-induced LBH upregulation. In conclusion, LBH upregulation in CMs in post-MI peri-infarct areas correlated with a hypoxic cardiac microenvironment and led to elevated exosomal LBH levels, promoting the activation of recipient CFs, which brings new insights into the studies and therapeutic strategies of post-MI cardiac repair.

Curcumin attenuates cadmium-induced atherosclerosis by regulating trimethylamine-N-oxide synthesis and macrophage polarization through remodeling the gut microbiota.

BACKGROUND: Studies have shown that cadmium (Cd) exposure primarily occurs through diet, and Cd ingestion is a risk factor for atherosclerosis (AS). However, the underlying mechanism remains unclear. As a target organ, the gastrointestinal tract may play a key role in Cd-induced AS. Additionally, as curcumin is insoluble in water but stable in the stomach of acidic pH, it may play regulative roles in the gut. OBJECTIVES: We assess the effect of Cd exposure on gut flora, trimethylamine-N-oxide (TMAO) metabolism and macrophage polarization, further investigate whether curcumin protects against Cd-induced AS by remodeling gut microbiota. METHODS AND RESULTS: The results of 16 S rRNA sequencing show that Cd exposure causes diversity reduction and compositional alteration of the microbial community, resulting in the increasing TMAO synthesis, the imbalance of lipid metabolism, and the M1-type macrophage polarization in the mouse model (ApoE-/-) of AS. As a result, the plaque area is increased with Cd exposure, shown by oil red O staining. TMAO synthesis is positively correlated with the concentration of blood Cd, and the dynamics of specific bacteria in this process were revealed at the phylum to genus levels. Moreover, the effects of intestinal flora and TMAO on Cd-induced AS are further confirmed via microbial transplantation from a mouse model not exposed to Cd, as the transplantation decreases plaque area. Finally, the gavage with curcumin reverses the Cd-induced pathological progression via gut flora restoration. CONCLUSIONS: We first demonstrate that Cd exposure worsens the progression of AS via intestinal flora imbalance and increased TMAO synthesis. Curcumin was verified as a potential novel intervention for preventing Cd-induced AS via remodeling gut microbiota. This study elucidates a new approach for treating AS in regions with significant Cd exposure.

YAP accelerates vascular senescence via blocking autophagic flux and activating mTOR.

Yes-associated protein (YAP), a major effector of the Hippo signalling pathway, is widely implicated in vascular pathophysiology processes. Here, we identify a new role of YAP in the regulation of vascular senescence. The inhibition or deficiency and overexpression of YAP were performed in human umbilical vein endothelial cells (HUVECs) and isolated vascular tissues. Cellular and vascular senescence was assessed by analysis of the senescence-associated ß-galactosidase (SA-ß-gal) and expression of senescence markers P16, P21, P53, TERT and TRF1. We found that YAP was highly expressed in old vascular tissues, inhibition and knockdown of YAP decreased senescence, while overexpression of YAP increased the senescence in both HUVECs and vascular tissues. In addition, autophagic flux blockage and mTOR pathway activation were observed during YAP-induced HUVECs and vascular senescence, which could be relieved by the inhibition and knockdown of YAP. Moreover, YAP-promoted cellular and vascular senescence could be relieved by mTOR inhibition. Collectively, our findings indicate that YAP may serve as a potential therapeutic target for ageing-associated cardiovascular disease.

Dihydromyricetin ameliorates vascular calcification in chronic kidney disease by targeting AKT signaling.

Vascular calcification is highly prevalent in chronic kidney disease (CKD), and is characterized by transdifferentiation from contractile vascular smooth muscle cells (VSMCs) into an osteogenic phenotype. However, no effective and therapeutic option to prevent vascular calcification is yet available. Dihydromyricetin (DMY), a bioactive flavonoid isolated from Ampelopsis grossedentata, has been found to inhibit VSMCs proliferation and the injury-induced neointimal formation. However, whether DMY has an effect on osteogenic differentiation of VSMCs and vascular calcification is still unclear. In the present study, we sought to investigate the effect of DMY on vascular calcification in CKD and the underlying mechanism. DMY treatment significantly attenuated calcium/phosphate-induced calcification of rat and human VSMCs in a dose-dependent manner, as shown by Alizarin Red S staining and calcium content assay, associated with down-regulation of osteogenic markers including type I collagen (COL I), Runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2) and osteocalcin (OCN). These results were further confirmed in aortic rings ex vivo. Moreover, DMY ameliorated vascular calcification in rats with CKD. Additionally, we found that AKT signaling was activated during vascular calcification, whereas significantly inhibited by DMY administration. DMY treatment significantly reversed AKT activator-induced vascular calcification. Furthermore, inhibition of AKT signaling efficiently attenuated calcification, which was similar to that after treatment with DMY alone, and DMY had a better inhibitory effect on calcification as compared with AKT inhibitor. The present study demonstrated that DMY has a potent inhibitory role in vascular calcification partially by inhibiting AKT activation, suggesting that DMY may act as a promising therapeutic candidate for patients suffering from vascular calcification.

Limb-bud and Heart (LBH) mediates proliferation, fibroblast-to-myofibroblast transition and EMT-like processes in cardiac fibroblasts.

Cardiac fibrosis is an important pathological change after myocardial infarction (MI). Its progression is essential for post-MI infarct healing, during which transforming growth factor beta1 (TGF-ß1) plays a critical role. Limb-bud and Heart (LBH), a newly discovered target gene of TGF-ß1, was shown to promote normal cardiogenesis. αB-crystallin (CRYAB), an LBH-interacting protein, was demonstrated to be involved in TGF-ß1-induced fibrosis. The roles and molecular mechanisms of LBH and CRYAB during cardiac fibrosis remain largely unexplored. In this study, we investigated the alterations of LBH and CRYAB expression in mouse cardiac tissue after MI. LBH and CRYAB were upregulated in activated cardiac fibroblasts (CFs), while in vitro TGF-ß1 stimulation induced the upregulation of LBH, CRYAB, and fibrogenic genes in primary CFs of neonatal rats. The results of the ectopic expression of LBH proved that LBH accelerated CF proliferation under hypoxia, mediated the expression of CRYAB and fibrogenic genes, and promoted epithelial-mesenchymal transition (EMT)-like processes in rat CFs, while subsequent CRYAB silencing reversed the effects induced by elevated LBH expression. We also verified the protein-protein interaction (PPI) between LBH and CRYAB in fibroblasts. In summary, our work demonstrated that LBH promotes the proliferation of CFs, mediates TGF-ß1-induced fibroblast-to-myofibroblast transition and EMT-like processes through CRYAB upregulation, jointly functioning in post-MI infarct healing. These findings suggest that LBH could be a promising potential target for the study of cardiac repair and cardiac fibrosis.

Trimethylamine-N-Oxide Promotes Vascular Calcification Through Activation of NLRP3 (Nucleotide-Binding Domain, Leucine-Rich-Containing Family, Pyrin Domain-Containing-3) Inflammasome and NF-κB (Nuclear Factor κB) Signals.

OBJECTIVES: Vascular calcification is highly prevalent in patients with chronic kidney disease. Increased plasma trimethylamine N-oxide (TMAO), a gut microbiota-dependent product, concentrations are found in patients undergoing hemodialysis. However, a clear mechanistic link between TMAO and vascular calcification is not yet established. In this study, we investigate whether TMAO participates in the progression of vascular calcification using in vitro, ex vivo, and in vivo models. Approach and Results: Alizarin red staining revealed that TMAO promoted calcium/phosphate-induced calcification of rat and human vascular smooth muscle cells in a dose-dependent manner, and this was confirmed by calcium content assay. Similarly, TMAO upregulated the expression of bone-related molecules including Runx2 (Runt-related transcription factor 2) and BMP2 (bone morphogenetic protein-2), suggesting that TMAO promoted osteogenic differentiation of vascular smooth muscle cells. In addition, ex vivo study also showed the positive regulatory effect of TMAO on vascular calcification. Furthermore, we found that TMAO accelerated vascular calcification in rats with chronic kidney disease, as indicated by Mico-computed tomography analysis, alizarin red staining and calcium content assay. By contrast, reducing TMAO levels by antibiotics attenuated vascular calcification in chronic kidney disease rats. Interestingly, TMAO activated NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome and NF-κB (nuclear factor κB) signals during vascular calcification. Inhibition of NLRP3 inflammasome and NF-κB signals attenuated TMAO-induced vascular smooth muscle cell calcification. CONCLUSIONS: This study for the first time demonstrates that TMAO promotes vascular calcification through activation of NLRP3 inflammasome and NF-κB signals, suggesting the potential link between gut microbial metabolism and vascular calcification. Reducing the levels of TMAO could become a potential treatment strategy for vascular calcification in chronic kidney disease.

Puerarin ameliorated pressure overload-induced cardiac hypertrophy in ovariectomized rats through activation of the PPARα/PGC-1 pathway.

Estrogen deficiency induces cardiac dysfunction and increases the risk of cardiovascular disease in postmenopausal women and in those who underwent bilateral oophorectomy. Previous evidence suggests that puerarin, a phytoestrogen, exerts beneficial effects on cardiac function in patients with cardiac hypertrophy. In this study, we investigated whether puerarin could prevent cardiac hypertrophy and remodeling in ovariectomized, aortic-banded rats. Female SD rats subjected to bilateral ovariectomy (OVX) plus abdominal aortic constriction (AAC). The rats were treated with puerarin (50 mg·kg-1 ·d-1, ip) for 8 weeks. Then echocardiography was assessed, and the rats were sacrificed, their heart tissues were extracted and allocated for further experiments. We showed that puerarin administration significantly attenuated cardiac hypertrophy and remodeling in AAC-treated OVX rats, which could be attributed to activation of PPARα/PPARγ coactivator-1 (PGC-1) pathway. Puerarin administration significantly increased the expression of estrogen-related receptor α, nuclear respiratory factor 1, and mitochondrial transcription factor A in hearts. Moreover, puerarin administration regulated the expression of metabolic genes in AAC-treated OVX rats. Hypertrophic changes could be induced in neonatal rat cardiomyocytes (NRCM) in vitro by treatment with angiotensin II (Ang II, 1 µM), which was attenuated by co-treatemnt with puerarin (100 µM). We further showed that puerarin decreased Ang II-induced accumulation of non-esterified fatty acids (NEFAs) and deletion of ATP, attenuated the Ang II-induced dissipation of the mitochondrial membrane potential, and improved the mitochondrial dysfunction in NRCM. Furthermore, addition of PPARα antagonist GW6471 (10 µM) partially abolished the anti-hypertrophic effects and metabolic effects of puerarin in NRCM. In conclusion, puerarin prevents cardiac hypertrophy in AAC-treated OVX rats through activation of PPARα/PGC-1 pathway and regulation of energy metabolism remodeling. This may provide a new approach to prevent the development of heart failure in postmenopausal women.

Osteomodulin is a Potential Genetic Target for Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic heart diseases. Its features include abnormal cardiomyocyte hypertrophy, microvascular dysfunction, and increased accumulation of intercellular matrix. We aim to unravel genes associated with the pathogenesis of HCM and provide a potential target for diagnosis and treatment. Key modules were identified by weighted gene co-expression network analysis (WGCNA). A miRNA-mRNA network was constructed with the predicted miRNA and the most likely hub gene was screened out for gene set enrichment analysis (GSEA). The diagnostic capacity of hub gene was verified by receiver operating characteristic (ROC) curves. Single-cell sequencing (sc-RNA seq) data of normal adult hearts were used to further predict the specific cell types expressing the hub gene. WGCNA assigned genes into different modules and found that the genes contained in the red module had the strongest positive correlation with HCM disease. 2.5% of the genes were common between DEG and hub genes. With the miRNA-mRNA network, osteomodulin (OMD) was identified as the most potential hub gene. GSEA showed that OMD was mainly involved in the synthesis of extracellular matrix and had a certain inhibitory effect on the immune system. The expression of OMD in HCM was validated and ROC curve analysis showed that OMD could distinguish HCM from controls with the area under the curve (AUC) > 0.7. The sc-RNA seq revealed that OMD was mainly expressed in the later stages of cardiac fibroblasts, suggesting that OMD may have an effect on fibroblasts, participating in the pathogenesis of HCM. OMD may serve as a biomarker and therapeutic target for HCM in the future.

CDC42 promotes vascular calcification in chronic kidney disease.

Vascular calcification is prevalent in patients with chronic kidney disease (CKD) and a major risk factor of cardiovascular disease. Vascular calcification is now recognised as a biological process similar to bone formation involving osteogenic differentiation of vascular smooth muscle cells (VSMCs). Cell division cycle 42 (CDC42), a Rac1 family member GTPase, is essential for cartilage development during endochondral bone formation. However, whether CDC42 affects osteogenic differentiation of VSMCs and vascular calcification remains unknown. In the present study, we observed a significant increase in the expression of CDC42 both in rat VSMCs and in calcified arteries during vascular calcification. Alizarin red staining and calcium content assay revealed that adenovirus-mediated CDC42 overexpression led to an apparent VSMC calcification in the presence of calcifying medium, accompanied with up-regulation of bone-related molecules including RUNX2 and BMP2. By contrast, inhibition of CDC42 by ML141 significantly blocked calcification of VSMCs in vitro and aortic rings ex vivo. Moreover, ML141 markedly attenuated vascular calcification in rats with CKD. Furthermore, pharmacological inhibition of AKT signal was shown to block CDC42-induced VSMC calcification. These findings demonstrate for the first time that CDC42 contributes to vascular calcification through a mechanism involving AKT signalling; this uncovered a new function of CDC42 in regulating vascular calcification. This may provide a potential therapeutic target for the treatment of vascular calcification in the context of CKD. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Gut microbe-derived metabolite trimethylamine N-oxide induces cardiac hypertrophy and fibrosis.

Trimethylamine N-oxide (TMAO), a gut microbe-derived metabolite of dietary choline and other trimethylamine-containing nutrients, has been linked to increased cardiovascular disease risk. It is unknown whether TMAO plays a role in the development of cardiac hypertrophy. Transverse aortic constriction (TAC) was performed to induce cardiac hypertrophy in Sprague-Dawley (SD) rats. We observed that TMAO levels were significantly elevated in SD rats after 6 weeks of TAC, suggesting the potential role of TMAO in regulating cardiac hypertrophy. In cultured cardiomyocytes, TMAO treatment stimulated cardiac hypertrophy, as indicated by increased cell area of cardiomyocytes and expression of hypertrophic markers including atrial natriuretic peptide (ANP) and beta-myosin heavy chain (ß-MHC). Additionally, TMAO treatment induced cardiac hypertrophy and cardiac fibrosis in SD rats. Reducing TMAO synthesis by antibiotics (Abs) attenuated TAC-induced cardiac hypertrophy and fibrosis. Furthermore, pharmacological inhibition of Smad3 by SIS3 significantly reduced the expression of ANP and ß-MHC, and cardiomyocyte cell size in TMAO-treated group. These data for the first time demonstrate that gut microbe-derived metabolite TMAO induces cardiac hypertrophy and fibrosis involving Smad3 signaling, suggesting that inhibition of gut microbes or generation of TMAO may become a potential target for the prevention and treatment of cardiac hypertrophy.

Memory Performance of People with Different Dementia Severity for Different Semantic Hierarchies.

BACKGROUND: Memory disorder is a significant symptom during early-stage Alzheimer's disease (AD). Changes in semantic memory are frequently seen in terms of forgetting names, loss of word meanings, and difficulties in linguistic expression. Significant semantic degeneration is not a normal phenomenon in elderly persons, and it may be an important sign in the early stages of progression of AD. METHODS: Thirty-four participants aged between 60 and 86 years were recruited for an experiment with a 3 × 4 × 2 factorial design that was conducted to explore the differences in semantic memory performance among controls with normal cognitive performance (NC), individuals classified as mildly cognitively impaired (MCI), and individuals with AD. RESULTS: The performance of participants diagnosed with mild AD was poorest for the attribute category, and there was no difference in response to different word frequencies. Although those diagnosed with MCI performed similarly to healthy elderly participants in terms of semantic memory, their performance profiles for different semantic hierarchies were similar to those of participants with AD. CONCLUSION: Semantic memory had degraded among participants with AD and MCI, and the rate of semantic degeneration was different in different semantic hierarchies.

A Promising Therapeutic Target for Metabolic Diseases: Neuropeptide Y Receptors in Humans.

Human neuropeptide Y (hNPY) is one of the most widely expressed neurotransmitters in the human central and peripheral nervous systems. It consists of 36 highly conserved amino acid residues, and was first isolated from the porcine hypothalamus in 1982. While it is the most recently discovered member of the pancreatic polypeptide family (which includes neuropeptide Y, gut-derived hormone peptide YY, and pancreatic polypeptide), NPY is the most abundant peptide found in the mammalian brain. In order to exert particular functions, NPY needs to bind to the NPY receptor to activate specific signaling pathways. NPY receptors belong to the class A or rhodopsin-like G-protein coupled receptor (GPCR) family and signal via cell-surface receptors. By binding to GPCRs, NPY plays a crucial role in various biological processes, including cortical excitability, stress response, food intake, circadian rhythms, and cardiovascular function. Abnormal regulation of NPY is involved in the development of a wide range of diseases, including obesity, hypertension, atherosclerosis, epilepsy, metabolic disorders, and many cancers. Thus far, five receptors have been cloned from mammals (Y1, Y2, Y4, Y5, and y6), but only four of these (hY1, hY2, hY4, and hY5) are functional in humans. In this review, we summarize the structural characteristics of human NPY receptors and their role in metabolic diseases.

Contributions of Nrf2 to Puerarin Prevention of Cardiac Hypertrophy and its Metabolic Enzymes Expression in Rats.

Previous evidence has suggested that puerarin may attenuate cardiac hypertrophy; however, the potential mechanisms have not been determined. Moreover, the use of puerarin is limited by severe adverse events, including intravascular hemolysis. This study used a rat model of abdominal aortic constriction (AAC)-induced cardiac hypertrophy to evaluate the potential mechanisms underlying the attenuating efficacy of puerarin on cardiac hypertrophy, as well as the metabolic mechanisms of puerarin involved. We confirmed that puerarin (50 mg/kg per day) significantly attenuated cardiac hypertrophy, upregulated Nrf2, and decreased Keap1 in the myocardium. Moreover, puerarin significantly promoted Nrf2 nuclear accumulation in parallel with the upregulated downstream proteins, including heme oxygenase 1, glutathione transferase P1, and NAD(P)H:quinone oxidoreductase 1. Similar results were obtained in neonatal rat cardiomyocytes (NRCMs) treated with angiotensin II (Ang II; 1 µM) and puerarin (100 µM), whereas the silencing of Nrf2 abolished the antihypertrophic effects of puerarin. The mRNA and protein levels of UGT1A1 and UGT1A9, enzymes for puerarin metabolism, were significantly increased in the liver and heart tissues of AAC rats and Ang II-treated NRCMs. Interestingly, the silencing of Nrf2 attenuated the puerarin-induced upregulation of UGT1A1 and UGT1A9. The results of chromatin immunoprecipitation-quantitative polymerase chain reaction indicated that the binding of Nrf2 to the promoter region of Ugt1a1 or Ugt1a9 was significantly enhanced in puerarin-treated cardiomyocytes. These results suggest that Nrf2 is the key regulator of antihypertrophic effects and upregulation of the metabolic enzymes UGT1A1 and UGT1A9 of puerarin. The autoregulatory circuits between puerarin and Nrf2-induced UGT1A1/1A9 are beneficial to attenuate adverse effects and maintain the pharmacologic effects of puerarin.

Resveratrol Ameliorates Cardiac Dysfunction by Inhibiting Apoptosis via the PI3K/Akt/FoxO3a Pathway in a Rat Model of Diabetic Cardiomyopathy.

The aim of this study was to explore the effect and mechanism of action of resveratrol (RSV) on cardiac function in diabetic cardiomyopathy (DCM). Hyperglycemia-induced apoptosis contributes to the pathogenic changes in DCM. RSV treatment inhibited high glucose-induced apoptosis of neonatal rat ventricular myocytes. Additionally, high glucose decreased cell viability, prevented serine-threonine kinase (Akt) and FoxO3a phosphorylation, and suppressed cytoplasmic translocation of FoxO3a. However, these effects of apoptosis were reversed by 10 µM of RSV. The PI3K inhibitor LY294002 abolished the RSV protective effect in vitro. RSV (5 or 50 mg·kg·d orally for 8 weeks) prevented the deterioration of cardiac function and structural cardiomyopathy in a streptozotocin-induced rat model of diabetes and reduced apoptosis in diabetic myocardium. Furthermore, it restored streptozotocin-impaired phosphorylation of Akt and FoxO3a (p-Akt and p-FoxO3a) and suppressed nuclear translocation of FoxO3a in vivo. Together, these data indicate that RSV has therapeutic potential against DCM by inhibiting apoptosis via the PI3K/Akt/FoxO3a pathway.

HDAC2 is required by the physiological concentration of glucocorticoid to inhibit inflammation in cardiac fibroblasts.

We previously suggested that endogenous glucocorticoids (GCs) may inhibit myocardial inflammation induced by lipopolysaccharide (LPS) in vivo. However, the possible cellular and molecular mechanisms were poorly understood. In this study, we investigated the role of physiological concentration of GCs in inflammation induced by LPS in cardiac fibroblasts and explored the possible mechanisms. The results showed that hydrocortisone at the dose of 127 ng/mL (equivalent to endogenous basal level of GCs) inhibited LPS (100 ng/mL)-induced productions of TNF-α and IL-1ß in cardiac fibroblasts. Xanthine oxidase/xanthine (XO/X) system impaired the anti-inflammatory action of GCs through downregulating HDAC2 activity and expression. Knockdown of HDAC2 restrained the anti-inflammatory effects of physiological level of hydrocortisone, and blunted the ability of XO/X system to downregulate the inhibitory action of physiological level of hydrocortisone on cytokines. These results suggested that HDAC2 was required by the physiological concentration of GC to inhibit inflammatory response. The dysfunction of HDAC2 induced by oxidative stress might be account for GC resistance and chronic inflammatory disorders during the cardiac diseases.

Trimetazidine attenuates pressure overload-induced early cardiac energy dysfunction via regulation of neuropeptide Y system in a rat model of abdominal aortic constriction.

BACKGROUND: Metabolism remodeling has been recognized as an early event following cardiac pressure overload. However, its temporal association with ventricular hypertrophy has not been confirmed. Moreover, whether trimetazidine could favorably affect this process also needs to be determined. The aim of the study was to explore the temporal changes of myocardial metabolism remodeling following pressure-overload induced ventricular hypertrophy and the potential favorable effect of trimetazidine on myocardial metabolism remodeling. METHODS: A rat model of abdominal aortic constriction (AAC)-induced cardiac pressure overload was induced. These rats were grouped as the AAC (no treatment) or TMZ group according to whether oral trimetazidine (TMZ, 40 mg/kg/d, for 5 days) was administered. Changes in cardiac structures were sequentially evaluated via echocardiography. The myocardial ADP/ATP ratio was determined to reflect the metabolic status, and changes in serum neuropeptide Y systems were evaluated. RESULTS: Myocardial metabolic disorder was acutely induced as evidenced by an increased ADP/ATP ratio within 7 days of AAC before the morphological changes in the myocardium, accompanied by up-regulation of serum oxidative stress markers and expression of fetal genes related to hypertrophy. Moreover, the serum NPY and myocardial NPY-1R, 2R, and 5R levels were increased within the acute phase of AAC-induced cardiac pressure overload. Pretreatment with TMZ could partly attenuate myocardial energy metabolic homeostasis, decrease serum levels of oxidative stress markers, attenuate the induction of hypertrophy-related myocardial fetal genes, inhibit the up-regulation of serum NPY levels, and further increase the myocardial expression of NPY receptors. CONCLUSIONS: Cardiac metabolic remodeling is an early change in the myocardium before the presence of typical morphological ventricular remodeling following cardiac pressure overload, and pretreatment with TMZ may at least partly reverse the acute metabolic disturbance, perhaps via regulation of the NPY system.

Puerarin prevents cardiac hypertrophy induced by pressure overload through activation of autophagy.

This study aimed to explore the effects of puerarin on autophagy in cardiac hypertrophy. Decreased 5'-adenosine monophosphate kinase (AMPK) activity alone with inhibited autophagy could be detected in rats within 3 weeks after aortic banding (AB). Puerarin treatment for 3 weeks in AB rats significantly restored autophagy. Administration of puerarin for 6 weeks effectively restricted cardiomyocyte hypertrophy and apoptosis. In an in vitro study, similar anti-hypertrophy and anti-apoptosis effects of puerarin on isoprenaline-induced H9c2 cells were also observed. After inhibition of autophagy by pretreatment with 3-methyladenine, the protective effects of puerarin were blocked. Further in vivo study demonstrated that puerarin significantly enabled phosphorylation of 5'-AMPK to be activated, subsequently inhibiting expression of the mammalian target of rapamycin (mTOR) target proteins S6 ribosomal protein and 4E-binding protein 1. All these data indicate that puerarin exerts protective effects against cardiomyocyte hypertrophy and apoptosis, partly by restoration of autophagy through AMPK/mTOR-mediated signaling.