(‑)‑Epicatechin protects against myocardial ischemia‑induced cardiac injury via activation of the PTEN/PI3K/AKT pathway

Green tea catechin prevents oxidative stress-regulated autophagy and apoptosis signaling, and inhibits tenderness in postmortem bovine longissimus thoracis et lumborum muscle

Although green tea catechin has been reported to be an antioxidant and preservative in meat, the extent to which it affects the tenderization of bovine muscle remains largely unknown. This study seeks to evaluate the effect of catechin on the interplay between apoptosis and autophagy, and subsequently, the development of bovine muscle tenderness. The results indicate that catechin significantly alleviated oxidative stress. A concomitant reduction of autophagic markers LC3-II/LC3-I ratio, Beclin-1, and Atg7 levels were caused by catechin. Besides, aforementioned autophagy inhibition was further augmented by PI3K/Akt/mTOR activation. Additionally, catechin protected against mitochondrial dysfunction and inhibited mitochondria-dependent caspase apoptosis pathway. Furthermore, there was a reciprocal inhibition between autophagy and apoptosis. Ultimately, tenderness at 24 and 120 h, an increase in the gap between muscle fiber bundles, and disintegration of myofibrillar architectures were all inhibited by catechin. Therefore, despite alleviating oxidative stress, catechin may hamper tenderization pattern of postmortem bovine muscle.

Small ubiquitin-related modifier (SUMO)ylation of SIRT1 mediates (-)-epicatechin inhibited- differentiation of cardiac fibroblasts into myofibroblasts

CONTEXT

(-)-Epicatechin (EPI) is a crucial substance involved in the protective effects of flavanol-rich foods. Previous studies have indicated EPI has a cardioprotective effect, but the molecular mechanisms in inhibition of cardiac fibrosis are unclear.

OBJECTIVE

We evaluated the effect of EPI in preventing cardiac fibrosis and the underlying molecular mechanism related to the SIRT1-SUMO1/AKT/GSK3β pathway.

MATERIALS AND METHODS

Cardiac fibrosis mice model was established with transaortic constriction (TAC). Male C57BL/6 mice were randomly separated into 4 groups. Mice received 1 mg/kg/day of EPI or vehicle orally for 4 weeks. The acutely isolated cardiac fibroblasts were induced to myofibroblasts with 1 µM angiotensin II (Ang II). The cardiac function was measured with the ultrasonic instrument. Histological analysis of mice's hearts was determined with H&E or Masson method. The protein level of fibrosis markers, SUMOylation of SIRT1, and AKT/GSK3β pathway were quantified by immunofluorescence and western blot.

RESULTS

EPI treatment (1 mg/kg/day) could reverse the TAC-induced decline in LVEF (TAC, 61.28% ± 1.33% vs. TAC + EPI, 74.00% ± 1.64%), LVFS (TAC, 28.16% ± 0.89% vs. TAC + EPI, 37.18% ± 1.29%). Meantime, we found that 10 µM EPI blocks Ang II-induced transformation of cardiac fibroblasts into myofibroblasts. The underlying mechanism of EPI-inhibited myofibroblasts transformation involves activation of SUMOylation of SIRT1 through SP1. Furthermore, SUMOylation of SIRT1 inhibited Ang II-induced fibrogenic effect via the AKT/GSK3β pathway.

CONCLUSION

EPI plays a protective effect on cardiac fibrosis by regulating the SUMO1-dependent modulation of SIRT1, which provides a theoretical basis for use in clinical therapies.

Supplementation with a Cocoa-Carob Blend, Alone or in Combination with Metformin, Attenuates Diabetic Cardiomyopathy, Cardiac Oxidative Stress and Inflammation in Zucker Diabetic Rats

Diabetic cardiomyopathy (DCM) is one of the main causes of mortality among diabetic patients, with oxidative stress and inflammation major contributors to its development. Dietary flavonoids show strong antioxidant and anti-inflammatory activities, although their potential additive outcomes in combination with antidiabetic drugs have been scarcely explored. The present study investigates the cardioprotective effects of a cocoa–carob blend (CCB) diet, rich in flavonoids, alone or in combination with metformin, in the development of DCM. Zucker diabetic fatty rats (ZDF) were fed with a CCB rich-diet or a control diet, with or without metformin for 12 weeks. Glucose homeostasis, cardiac structure and function, and oxidative and inflammatory biomarkers were analysed. CCB improved glucose homeostasis, and mitigated cardiac dysfunction, hypertrophy, and fibrosis in ZDF rats. Mechanistically, CCB counteracted oxidative stress in diabetic hearts by down-regulating NADPH oxidases, reducing reactive oxygen species (ROS) generation and modulating the sirtuin-1 (SIRT1)/ nuclear factor E2-related factor 2 (Nrf2) signalling pathway, overall improving antioxidant defence. Moreover, CCB suppressed inflammatory and fibrotic reactions by inhibiting nuclear factor kappa B (NFκB) and pro-inflammatory and pro-fibrotic cytokines. Noteworthy, several of these effects were further improved in combination with metformin. Our results demonstrate that CCB strongly prevents the cardiac remodelling and dysfunction observed in diabetic animals, highlighting its potential, alone or in adjuvant therapy, for treating DCM.

miRNA-425-5p enhances diffuse large B cell lymphoma growth by targeting PTEN

BACKGROUND

At present, cancer is one of the greatest threats to mankind, and is associated with the highest rates of morbidity and comorbidity. Recently, the advancements in molecular biology have led to an in-depth understanding of the underlying pathophysiology, which may further impact the lead time in the context of early discovery and effective therapy of cancer. Therefore, the present study proposes a better understanding of the role of micro(miR)-425-5p in diffuse large B-cell lymphoma (DLBC).

METHODS

qRT-PCR was carried out to detect the relevant proteins, miRNA and mRNA RNA gene expression in DLBC cells. The effect of miR-425-5p on DLBC growth was examined by CCK-8 and colony formation assays. The binding relationship between genes was verified by dual-luciferase reporter gene assay.

RESULTS

We demonstrated how the over-expression of miR-425-5p can lead to increased progression of DLBC by increasing the cellular proliferation rate and colony-forming ability. Additionally, we also found that the expression of miR-425-5p could be significantly inhibited on the basis of phosphatase and tensin homolog (PTEN) signaling pathways.

CONCLUSIONS

The present study concludes that miR-425-5p is responsible for the oncogenic progression and relapse of DLBC tumorigenesis via PTEN/PI3K signaling, which can thus be effectively used to achieve better therapeutic outcomes.

The roles of signaling pathways in cardiac regeneration

In recent years, knowledge of cardiac regeneration mechanisms has dramatically expanded. Regeneration can replace lost parts of organs, common among animal species. The heart is commonly considered an organ with terminal development, which has no reparability potential during post-natal life; however, some intrinsic regeneration capacity has been reported for cardiac muscle, which opens novel avenues in cardiovascular disease treatment. Different endogenous mechanisms were studied for cardiac repairing and regeneration in recent decades. Survival, proliferation, inflammation, angiogenesis, cell-cell communication, cardiomyogenesis, and anti-aging pathways are the most important mechanisms that have been studied in this regard. Several in vitro and animal model studies focused on proliferation induction for cardiac regeneration reported promising results. These studies have mainly focused on promoting proliferation signaling pathways and demonstrated various signaling pathways such as Wnt, PI3K/Akt, IGF-1, TGF-β, Hippo, and VEGF signaling cardiac regeneration. Therefore, in this review, we intended to discuss the connection between different critical signaling pathways in cardiac repair and regeneration.

Pharmacology of Catechins in Ischemia-Reperfusion Injury of the Heart

Catechins represent a group of polyphenols that possesses various beneficial effects in the cardiovascular system, including protective effects in cardiac ischemia-reperfusion (I/R) injury, a major pathophysiology associated with ischemic heart disease, myocardial infarction, as well as with cardioplegic arrest during heart surgery. In particular, catechin, (−)-epicatechin, and epigallocatechin gallate (EGCG) have been reported to prevent cardiac myocytes from I/R-induced cell damage and I/R-associated molecular changes, finally, resulting in improved cell viability, reduced infarct size, and improved recovery of cardiac function after ischemic insult, which has been widely documented in experimental animal studies and cardiac-derived cell lines. Cardioprotective effects of catechins in I/R injury were mediated via multiple molecular mechanisms, including inhibition of apoptosis; activation of cardioprotective pathways, such as PI3K/Akt (RISK) pathway; and inhibition of stress-associated pathways, including JNK/p38-MAPK; preserving mitochondrial function; and/or modulating autophagy. Moreover, regulatory roles of several microRNAs, including miR-145, miR-384-5p, miR-30a, miR-92a, as well as lncRNA MIAT, were documented in effects of catechins in cardiac I/R. On the other hand, the majority of results come from cell-based experiments and healthy small animals, while studies in large animals and studies including comorbidities or co-medications are rare. Human studies are lacking completely. The dosages of compounds also vary in a broad scale, thus, pharmacological aspects of catechins usage in cardiac I/R are inconclusive so far. Therefore, the aim of this focused review is to summarize the most recent knowledge on the effects of catechins in cardiac I/R injury and bring deep insight into the molecular mechanisms involved and dosage-dependency of these effects, as well as to outline potential gaps for translation of catechin-based treatments into clinical practice.

Boosting Akt Pathway by Rupatadine Modulates Th17/Tregs Balance for Attenuation of Isoproterenol-Induced Heart Failure in Rats

Disruption of Th17/Tregs homeostasis plays a crucial role in governing the immune response during myocardial fibrosis and its progression to heart failure. The present study aimed to assess for the first time the possible protection afforded by rupatadine against isoproterenol-induced heart failure in rats. It also explored the role of PI3k/Akt as a possible mechanistic pathway, through which rupatadine could modulate Th17/Tregs balance to display its effect. Isoproterenol (85 and 170 mg/kg/day) was injected subcutaneously for 2 successive days, respectively and rupatadine (4 mg/kg/day) was then given orally for 14 days with or without wortmannin (PI3K/Akt inhibitor). Rupatadine succeeded to completely ameliorate isoproterenol-induced cardiac dysfunction as demonstrated by improvements of electrocardiographic and echocardiographic measurements. Moreover, rupatadine prevented the marked elevation of PAF and oxidative stress in addition to Th17 promoting cytokines (IL-6, IL-23, and TGF-β). Accordingly, rupatadine prevented Th17 stimulation or expansion as indicated by increased Foxp3/RORγt ratio and decreased production of its pro-inflammatory cytokine (IL-17). Rupatadine treatment mitigated isoproterenol-induced activation of STAT-3 signaling and the imbalance in p-Akt/total Akt ratio affording marked decrease in atrogin-1 and apoptotic biomarkers. Finally, this therapy was effective in averting cardiac troponin loss and reverting the histological alterations as assessed by myocardial fibrosis and hypertrophy grading. Contrariwise, co-administration of wortmannin mostly attenuated the protective effects of rupatadine affording more or less similar results to that of isoproterenol-untreated rats. In conclusion, rupatadine could be an effective therapy against the development of isoproterenol-induced heart failure where PI3K/Akt pathway seems to play a crucial role in its protective effect.

Tissue mechanics and expression of TROP2 in oral squamous cell carcinoma with varying differentiation

Background

Trophoblast cell surface antigen 2 (TROP2) is overexpressed in many squamous cell carcinomas and promotes tumor development and invasion. The association between TROP2 expression and occurrence and development of oral squamous cell carcinoma (OSCC) remains to be understood.

Methods

We investigated the role of TROP2 in OSCC patients using a combination of biophysical approaches. A total of 108 OSCC patient specimens with varying degrees of differentiation were subjected to hematoxylin and eosin staining, immunohistochemistry, Kaplan-Meier survival curve analysis, and atomic force microscopy to analyze TROP2 expression, morphology, and mechanical properties of OSCC tissues.

Results

TROP2 was overexpressed in 34% of poorly differentiated OSCC samples. High levels of TROP2 were associated with 10.2% survival rate lower than 45.4% and patient age (odds ratio [OR] = 0.437, P = 0.039, 95% confidence interval [CI, 0.198–0.966]), tumor size (OR = 13.148, P = 0.000, 95% CI [5.060–34.168]), and TNM stage (OR = 0.141, P = 0.000, 95% CI [0.082–0.244]). Average surface roughness of low, medium, and highly differentiated OSCC tissues were 448.9 ± 54.8, 792.7 ± 83.6, and 993.0 ± 104.3 nm, respectively. The Pearson coefficient revealed a negative association between tumor stiffness and TROP2 expression (r = − 0.84, P < 0.01).

Conclusion

Overexpression of TROP2 negatively associated with patient survival, degree of tumor differentiation, and tissue mechanics. Taken together, our findings demonstrated that TROP2 may be an indicator of OSCC differentiation leading to the altered mechanical properties of OSCC tissues.

miRNA-425-5p enhances lung cancer growth via the PTEN/PI3K/AKT signaling axis

Background

miRNAs regulate a multitude of cellular processes and their aberrant regulation is linked to human cancer. However, the role of miR-425-5p in lung cancer (LCa) is still largely unclear. Here, we explored the role of miR-425-5p during LCa tumorigenesis.

Methods

Cell proliferation was evaluated by cell counting Kit-8 and colony formation assay. Western blot and real-time PCR were accordingly used to detect the relevant proteins, miRNA and gene expression. Luciferase reporter assays were used to illustrate the interaction between miR-425-5p and PTEN.

Results

We demonstrate that miR-425-5p is overexpressed in LCa tissue and enhances the proliferative and colony formation capacity of the LCa cell lines A549 and NCI-H1299. Through predictive binding assays, PTEN was identified as a direct gene target and its exogenous expression inhibited the pro-cancer effects of miR-425-5p. Through its ability to down-regulate PTEN, miR-425-5p activated the PI3K/AKT axis.

Conclusion

We conclude that miR-425-5p promotes LCa tumorigenesis through PTEN/PI3K/AKT signaling.

Advances in physiological functions and mechanisms of (-)-epicatechin

(-)-Epicatechin (EC) is a flavanol easily obtained through the diet and is present in tea, cocoa, vegetables, fruits, and cereals. Recent studies have shown that EC protects human health and exhibits prominent anti-oxidant and anti-inflammatory activities, enhances muscle performance, improves symptoms of cardiovascular and cerebrovascular diseases, prevents diabetes, and protects the nervous system. With the development of modern medical and biotechnology research, the mechanisms of action associated with EC toward various chronic diseases are becoming more apparent, and the pharmacological development and utilization of EC has been increasingly clarified. Currently, there is no comprehensive systematic introduction to the effects of EC and its mechanisms of action. This review presents the latest research progress and the role of EC in the prevention and treatment of various chronic diseases and its protective health effects and provides a theoretical basis for future research on EC.

TROP2 increases growth and metastasis of human oral squamous cell carcinoma through activation of the PI3K/Akt signaling pathway

Most malignant neoplasms of the oral cavity are oral squamous cell carcinoma (OSCC), which is a type of highly malignant tumor with a propensity for forming distant metastases. Trophoblast cell surface antigen 2 (TROP2) is a transmembrane protein that is overexpressed in several types of tumor cells, although its role and regulatory mechanism in OSCC have not been determined. The aim of the present study was to examine the effects of TROP2 in human OSCC cell lines. The present study demonstrated that TROP2 protein expression was upregulated in OSCC cell lines. Transfection of short hairpin RNA (shRNA) targeting TROP2 (sh‑TROP2) reduced cell proliferation, migration and invasion of OSCC cell lines, whereas overexpression of TROP2 increased proliferation, migration and invasion. sh‑TROP2 transfection in OSCC cell lines inhibited tumor growth in OSCC mouse models. Furthermore, TROP2 expression activated the phosphoinositide 3‑kinase (PI3K)/Akt signaling pathway in human OSCC cells. These results suggest that TROP2 induces cell growth, migration and invasion through activation of the PI3K/Akt signaling pathway in OSCC cells.

Effects and Mechanisms of Tea and Its Bioactive Compounds for the Prevention and Treatment of Cardiovascular Diseases: An Updated Review

Cardiovascular diseases (CVDs) are critical global public health issues with high morbidity and mortality. Epidemiological studies have revealed that regular tea drinking is inversely associated with the risk of CVDs. Additionally, substantial in vitro and in vivo experimental studies have shown that tea and its bioactive compounds are effective in protecting against CVDs. The relevant mechanisms include reducing blood lipid, alleviating ischemia/reperfusion injury, inhibiting oxidative stress, enhancing endothelial function, attenuating inflammation, and protecting cardiomyocyte function. Moreover, some clinical trials also proved the protective role of tea against CVDs. In order to provide a better understanding of the relationship between tea and CVDs, this review summarizes the effects of tea and its bioactive compounds against CVDs and discusses potential mechanisms of action based on evidence from epidemiological, experimental, and clinical studies.

Aqueous Extract of Davallia mariesii Attenuates 6-Hydroxydopamine-Induced Oxidative Damage and Apoptosis in B35 Cells Through Inhibition of Caspase Cascade and Activation of PI3K/AKT/GSK-3β Pathway

The medicinal ferns of Polydiaceae and Davalliaceae species are called "Gusuibu" by Chinese physicians and used as antiaging dietary medicines. Our previous report revealed that Drynaria fortunei (Polydiaceae) protected against 6-hydroxydopamine (6-OHDA)-induced oxidative damage via the PI3K/AKT pathway in B35 neuroblastoma cells. The present study compares the antioxidant phytoconstituent contents and radical scavenging capacities of five Davalliaceae species. The further aim was to clarify the protective mechanism of Davallia mariesii (DM) against 6-OHDA-induced oxidative damage and apoptosis in B35 cells. The results show that Araiostegia perdurans (AP) and DM extracts have better radical scavenging capacities against 1,1-diphenyl-2-picryhydrazyl (DPPH) and reactive oxygen species (ROS) than other Davalliaceae species. However, only DM extract inhibited 6-OHDA autoxidation under cell-free systems and increased cell viability, compared to B35 cells solely exposed to 6-OHDA. DM extract decreased apoptosis and restored mitochondrial expression in 6-OHDA-treated B35 cells. Additional data indicated that DM extract decreased intracellular ROS and nitric oxide levels generated by 6-OHDA exposure. DM extract also restored glutathione (GSH) levels and the activities of glutathione peroxidase and reductase, and then decreased the elevated malondialdehyde (MDA) levels. Finally, DM extract regulated the protein expression of the caspase cascade and PI3K/AKT/GSK-3β pathways. These results suggest that the protective mechanism of DM extract against 6-OHDA-induced oxidative damage and apoptosis might be related to its radical scavenging capacity, maintaining the mitochondrial function to inhibit the Bcl-2/caspase cascade pathway and activating intracellular antioxidant defenses (GSH recycling, HO-1 and NQO-1) by modulating the activation of the PI3K/AKT/GSK-3β pathway.