Up-regulation of Nrf2/HO-1 and inhibition of TGF-β1/Smad2/3 signaling axis by daphnetin alleviates transverse aortic constriction-induced cardiac remodeling in mice

l-Arginine: A multifaceted regulator of diabetic cardiomyopathy

In diabetes mellitus, dysregulated glucose and lipid metabolism lead to diabetic cardiomyopathy (DCM) by imparting pathological myocardial remodeling and cellular injury. Accelerated glycation, oxidative stress, and activated inflammatory pathways culminate in cardiac fibrosis and hypertrophy in DCM. The regulatory effects of l-Arginine (L-Arg) have been elucidated in the pathological changes of DCM, including myocardial fibrosis, hypertrophy, and apoptosis, by inhibiting glycation and oxidative stress-induced inflammation. Disturbed L-Arg metabolism and decreased intracellular L-Arg pool are correlated with the progression of DCM; therefore, L-Arg supplementation has been prescribed for various cardiovascular dysfunctions. This review expands the therapeutic potential of L-Arg supplementation in DCM by elucidating its molecular mechanism of action and exploring potential clinical outcomes.

Mevastatin-Induced HO-1 Expression in Cardiac Fibroblasts: A Strategy to Combat Cardiovascular Inflammation and Fibrosis

Mevastatin (MVS) is known for its anti-inflammatory effects, potentially achieved by upregulating heme oxygenase-1 (HO-1), an enzyme involved in cytoprotection against oxidative injury. Nonetheless, the specific processes by which MVS stimulates HO-1 expression in human cardiac fibroblasts (HCFs) are not yet fully understood. In this study, we found that MVS treatment increased HO-1 mRNA and protein levels in HCFs. This induction was inhibited by pretreatment with specific inhibitors of p38 MAPK, JNK1/2, and FoxO1, and by siRNAs targeting NOX2, p47phox, p38, JNK1, FoxO1, Keap1, and Nrf2. MVS also triggered ROS generation and activated JNK1/2 and p38 MAPK, both attenuated by NADPH oxidase or ROS inhibitors. Additionally, MVS promoted the phosphorylation of FoxO1 and Nrf2, which was suppressed by p38 MAPK or JNK1/2 inhibitor. Furthermore, MVS inhibited TNF-α-induced NF-κB activation and vascular cell adhesion molecule-1 (VCAM-1) expression via the HO-1/CO pathway in HCFs. In summary, the induction of HO-1 expression in HCFs by MVS is mediated through two primary signaling pathways: NADPH oxidase/ROS/p38 MAPK, and JNK1/2/FoxO1 and Nrf2. This research illuminates the underlying processes through which MVS exerts its anti-inflammatory effects by modulating HO-1 in cardiac fibroblasts.

Daphnetin ameliorates diabetic cardiomyopathy by regulating inflammation and endoplasmic reticulum stress-induced apoptosis

Daphnetin has been demonstrated to exert beneficial effects on diabetes mellitus and renal complications. However, the role and molecular mechanism of daphnetin in diabetic cardiomyopathy (DCM) remain unclear. In this study, rats were injected with streptozotocin (STZ) to induce diabetes. The diabetic rats were then administered daphnetin (1 and 4 mg/kg) or dimethyl sulfoxide (DMSO) daily for 12 weeks. The results demonstrated that the diabetic rats exhibited elevated blood glucose levels, which were dose-dependently ameliorated by daphnetin. At 13 weeks following STZ injection, the rats exhibited typical diabetic signs, cardiac dysfunction, and evident pathological alterations in myocardial tissues. The administration of daphnetin to diabetic rats resulted in improvement in cardiac function, reductions in myocardial injury biomarkers, and the inhibition of myocardial fibrosis. Furthermore, daphnetin treatment suppressed inflammation and endoplasmic reticulum stress-induced apoptosis in a dose-dependent manner. Additionally, daphnetin exhibited partial blockade of the activation of mitogen-activated protein kinase pathways induced by diabetes. These findings indicate that daphnetin may be a promising therapeutic agent for the treatment of DCM.

Dental pulp stem cell‑derived extracellular vesicles loaded with hydrogels promote osteogenesis in rats with alveolar bone defects

Alveolar bone defects caused by inflammation, trauma and tumors adversely affect periodontal health, causing tooth loosening or dentition defects, thus affecting denture or implant repair. Advancements in tissue engineering technology and stem cell biology have significantly improved the regenerative reconstruction of alveolar bone defects. The multiple trophic activities of extracellular vesicles (EVs) produced by mesenchymal stem cells play important roles in exerting their therapeutic effects. Several studies have reported the role of dental pulp stem cells (DPSCs) in bone regeneration, but the regenerative effects of DPSC‑EVs on alveolar bone defects are unclear. In the present study, the osteogenic effects of DPSC‑EVs on Hertwig's epithelial root sheath (HERS) cells in vitro and their osteoinductive effects in an alveolar bone defect rat model were investigated. The results showed that DPSC‑EVs significantly promoted the expression of osteogenic genes, such as runt‑related transcription factor 2 and alkaline phosphatase, and increased the osteogenic differentiation capability of HERS. These findings suggested that transforming growth factor β1 inhibition decreased DPSC‑EV‑induced Smad, MAPK and ERK phosphorylation in HERS. In vivo, DPSC‑EV‑loaded hydrogels were transplanted into the alveolar sockets of Sprague‑Dawley rats and observed for eight weeks. The new bone grew concentrically in the DPSC‑EV or DPSC‑EV‑loaded hydrogel group, with greater bone mass than that in the control group, and the bone volume/total volume increased notably. The results confirmed the osteogenic and osteoinductive effects of DPSC‑EVs and DPSC‑Exo‑loaded hydrogels on alveolar bone defects. Due to their low immunogenicity, high stability, good biocompatibility and osteogenic propensity, DPSC‑EV‑loaded hydrogels are a safe cell‑free therapeutic approach for defective alveolar bone regeneration.

SIRT3 sulfhydration using hydrogen sulfide inhibited angiotensin II-induced atrial fibrosis and vulnerability to atrial fibrillation via suppression of the TGF-β1/smad2/3 signalling pathway

Atrial fibrosis is associated with the occurrence of atrial fibrillation (AF) and regulated by the transforming growth factor-β1 (TGF-β1)/Smad2/3 signalling pathway. Unfortunately, the mechanisms of regulation of TGF-β1/Smad2/3-induced atrial fibrosis and vulnerability to AF remain still unknown. Previous studies have shown that sirtuin3 (SIRT3) sulfhydration has strong anti-fibrotic effects. We hypothesised that SIRT3 sulfhydration inhibits angiotensin II (Ang-II)-induced atrial fibrosis via blocking the TGF-β1/Smad2/3 signalling pathway. In this study, we found that SIRT3 expression was decreased in the left atrium of patients with AF compared to that in those with sinus rhythm (SR). In vitro, SIRT3 knockdown by small interfering RNA significantly expanded Ang-II-induced atrial fibrosis and TGF-β1/Smad2/3 signalling pathway activation, whereas supplementation with Sodium Hydrosulfide (NaHS, exogenous hydrogen sulfide donor and sulfhydration agonist) and SIRT3 overexpression using adenovirus ameliorated Ang-II-induced atrial fibrosis. Moreover, we observed suppression of the TGF-β1/Smad2/3 pathway when Ang-II was combined with NaHS treatment, and the effect of this co-treatment was consistent with that of Ang-II combined with LY3200882 (Smad pathway inhibitor) on reducing atrial fibroblast proliferation and cell migration in vitro. Supplementation with dithiothreitol (DTT, a sulfhydration inhibitor) and adenovirus SIRT3 shRNA blocked the ameliorating effect of NaHS and AngII co-treatment on atrial fibrosis in vitro. Finally, continued treatment with NaHS in rats ameliorated atrial fibrosis and remodelling, and further improved AF vulnerability induced by Ang-II, which was reversed by DTT and adenovirus SIRT3 shRNA, suggesting that SIRT3 sulfhydration might be a potential therapeutic target in atrial fibrosis and AF.

Fibroblast-derived miR-425-5p alleviates cardiac remodelling in heart failure via inhibiting the TGF-β1/Smad signalling

The pathological activation of cardiac fibroblasts (CFs) plays a crucial role in the development of pressure overload-induced cardiac remodelling and subsequent heart failure (HF). Growing evidence demonstrates that multiple microRNAs (miRNAs) are abnormally expressed in the pathophysiologic process of cardiovascular diseases, with miR-425 recently reported to be potentially involved in HF. In this study, we aimed to investigate the effects of fibroblast-derived miR-425-5p in pressure overload-induced HF and explore the underlying mechanisms. C57BL/6 mice were injected with a recombinant adeno-associated virus specifically designed to overexpress miR-425-5p in CFs, followed by transverse aortic constriction (TAC) surgery. Neonatal mouse CFs (NMCFs) were transfected with miR-425-5p mimics and subsequently stimulated with angiotensin II (Ang II). We found that miR-425-5p levels were significantly downregulated in HF mice and Ang II-treated NMCFs. Notably, fibroblast-specific overexpression of miR-425-5p markedly inhibited the proliferation and differentiation of CFs, thereby alleviating myocardial fibrosis, cardiac hypertrophy and systolic dysfunction. Mechanistically, the cardioprotective actions of miR-425-5p may be achieved by targeting the TGF-β1/Smad signalling. Interestingly, miR-425-5p mimics-treated CFs could also indirectly affect cardiomyocyte hypertrophy in this course. Together, our findings suggest that fibroblast-derived miR-425-5p mitigates TAC-induced HF, highlighting miR-425-5p as a potential diagnostic and therapeutic target for treating HF patients.

Attenuating mitochondrial dysfunction-derived reactive oxygen species and reducing inflammation: the potential of Daphnetin in the viral pneumonia crisis

Amidst the global burden of viral pneumonia, mitigating the excessive inflammatory response induced by viral pneumonia has emerged as a significant challenge. Pneumovirus infections can lead to the persistent activation of M1 macrophages, culminating in cytokine storms that exacerbate pulmonary inflammation and contribute to the development of pulmonary fibrosis. Mitochondria, beyond their role as cellular powerhouses, are pivotal in integrating inflammatory signals and regulating macrophage polarization. Mitochondrial damage in alveolar macrophages is postulated to trigger excessive release of reactive oxygen species (ROS), thereby amplifying macrophage-mediated inflammatory pathways. Recent investigations have highlighted the anti-inflammatory potential of Daphnetin, particularly in the context of cardiovascular and renal disorders. This review elucidates the mechanisms by which viral infection-induced mitochondrial damage promotes ROS generation, leading to the phenotypic shift of alveolar macrophages towards a pro-inflammatory state. Furthermore, we propose a mechanism whereby Daphnetin attenuates inflammatory signaling by inhibiting excessive release of mitochondrial ROS, thus offering mitochondrial protection. Daphnetin may represent a promising pharmacological intervention for viral pneumonia and could play a crucial role in addressing future pandemics.

Daphnetin modulates GLP-1R to alleviate cognitive dysfunction in diabetes: implications for inflammation and oxidative stress

Daphnetin exerts certain pharmacological function on a variety of diseases, but its role in diabetic cognitive dysfunction has not been elucidated. In this study, we carried a series of pharmacological studies of GLP-1R with daphnetin. In rats and PC12 cells, we found that daphnetin could alleviate diabetic cognitive dysfunction and increase the expression level of GLP-1R. Additionally, the anti-diabetic cognitive dysfunction effect of DAP was accompanied by the inhibition of inflammation and oxidative stress. Further in-depth studies demonstrated that the inhibition GLP-1R enhanced the protective effect of daphnetin, whilst, the overexpression of GLP-1R weakened the protective effect of daphnetin. These results indicated that daphnetin protects diabetes cognitive dysfunction by regulating GLP-1R-mediated inflammation and oxidative stress, act as a GLP-1R agonist. The study further demonstrated that daphnetin has great value in preventing cognitive dysfunction in type 2 diabetes, and GLP-1R is a key potential target for the treatment of related diseases.

Ferroptosis in diabetic cardiomyopathy: Advances in cardiac fibroblast-cardiomyocyte interactions

Diabetic cardiomyopathy (DCM) is a common complication of diabetes, and its pathogenesis remains elusive. Ferroptosis, a process dependent on iron-mediated cell death, plays a crucial role in DCM via disrupted iron metabolism, lipid peroxidation, and weakened antioxidant defenses. Hyperglycemia, oxidative stress, and inflammation may exacerbate ferroptosis in diabetes. This review emphasizes the interaction between cardiac fibroblasts and cardiomyocytes in DCM, influencing ferroptosis occurrence. By exploring ferroptosis modulation for potential therapeutic targets, this article offers a fresh perspective on DCM treatment. The study systematically covers the interplay, mechanisms, and targeted drugs linked to ferroptosis in DCM development.

Caffeic acid mitigates myocardial fibrosis and improves heart function in post-myocardial infarction by inhibiting transforming growth factor-β receptor 1 signaling pathways

Myocardial fibrosis is a pathological, physiological change that results from alterations, such as inflammation and metabolic dysfunction, after myocardial infarction (MI). Excessive fibrosis can cause cardiac dysfunction, ventricular remodeling, and heart failure. Caffeic acid (CA), a natural polyphenolic acid in various foods, has cardioprotective effects. This study aimed to explore whether CA exerts a cardioprotective effect to inhibit myocardial fibrosis post-MI and elucidate the underlying mechanisms. Histological observations indicated that CA ameliorated ventricular remodeling induced by left anterior descending coronary artery ligation in MI mice and partially restored cardiac function. CA selectively targeted transforming growth factor-β receptor 1 (TGFBR1) and inhibited TGFBR1-Smad2/3 signaling, reducing collagen deposition in the infarcted area of MI mice hearts. Furthermore, cell counting (CCK-8) assay, 5-ethynyl-2'-deoxyuridine assay, and western blotting revealed that CA dose-dependently decreased the proliferation, collagen synthesis, and activation of the TGFBR1-Smad2/3 pathway in primary cardiac fibroblasts (CFs) stimulated by TGF-β1 in vitro. Notably, TGFBR1 overexpression in CFs partially counteracted the inhibitory effects of CA. These findings suggest that CA effectively mitigates myocardial fibrosis and enhances cardiac function following MI and that this effect may be associated with the direct targeting of TGFBR1 by CA.

Zhen-wu-tang protects against myocardial fibrosis by inhibiting M1 macrophage polarization via the TLR4/NF-κB pathway

BACKGROUND

Myocardial fibrosis is a risk factor that contributes to the increase in the incidence of cardiovascular disease and death, posing a significant threat to human health. Zhen-wu-tang (ZWT) is a classical Chinese medicinal recipe that has been extensively used to manage cardiovascular disorders throughout history. However, the fundamental processes involved in its effects were not clear.

OBJECTIVE

This study examined the therapeutic effects of ZWT on myocardial fibrosis induced by isoproterenol (ISO) in mice, the effect of regulation and underlying mechanism on the polarization of M1 macrophage.

METHODS

In vivo, a myocardial fibrosis mouse model was induced via intraperitoneal infusion of isoproterenol (ISO). ZWT or captopril (CAP) was administered intragastrically for 30 days. Cardiac function was evaluated by electrocardiogram (ECG) and echocardiography. By analysing myocardial fibrosis pathomorphologically and identifying fibrosis-related indicators, the protective effect of the ZWT on the heart was evaluated. A model of macrophage polarization was established in vitro by activating RAW264.7 cells with lipopolysaccharide (LPS). The regulatory effects of ZWT on macrophage polarization and the signalling pathways involved were examined by immunofluorescence staining, Western blotting (WB), quantitative real-time PCR (qRT-PCR) and siRNA transfection.

RESULTS

ZWT improved cardiac function; reduced fibrotic deposition in cardiac tissues; decreased α-SMA, collagen I, and collagen III levels; and inhibited myocardial fibrosis in mice with ISO-induced myocardial fibrosis. Furthermore, the results showed that ZWT could suppress M1 macrophage polarization by downregulating the expression of CD86 and iNOS in vitro and in vivo. Finally, the results confirmed that ZWT could significantly reduce TLR4/NF-κB signalling pathway activation.

CONCLUSION

ZWT showed therapeutic effects on ISO-induced myocardial fibrosis mice, and reduced M1 macrophages polarization through inhibiting TLR4/NF-κB pathway, suggesting that ZWT is a promising drug for myocardial fibrosis treatment.

The molecular effects underlying the pharmacological activities of daphnetin

As an increasingly well-known derivative of coumarin, daphnetin (7,8-dithydroxycoumarin) has demonstrated various pharmacological activities, including anti-inflammation, anti-cancer, anti-autoimmune diseases, antibacterial, organ protection, and neuroprotection properties. Various studies have been conducted to explore the action mechanisms and synthetic methods of daphnetin, given its therapeutic potential in clinical. Despite these initial insights, the precise mechanisms underlying the pharmacological activities of daphnetin remain largely unknown. In order to address this knowledge gap, we explore the molecular effects from the perspectives of signaling pathways, NOD-like receptor protein 3 (NLRP3) inflammasome and inflammatory factors; and try to find out how these mechanisms can be utilized to inform new combined therapeutic strategies.

Cobalt protoporphyrin promotes heme oxygenase 1 expression and ameliorates cardiac dysfunction in long-term fasting mice

BACKGROUND

The association between malnutrition and cardiac dysfunction has been reported. Heme oxygenase (HO)-1 played protective roles in the animals functioning as a myocardial infarction, heart failure, or cardiomyopathy model. We hypothesized that the administration of HO-1 inducer, cobalt protoporphyrin (CoPP) reduces oxidative stress and ameliorates cardiac systolic dysfunction in long-term fasting mice.

METHODS

C57BL/6 J mice were classified into three groups: fed mice (fed group), 48-h fasting mice with a single intraperitoneal injection of the corresponding vehicle (fasting group), and 48-h fasting mice with a single intraperitoneal injection of 5 mg/kg CoPP (CoPP group).

RESULTS

The fasting group showed a significant increase in heme and 4-hydroxy-2-nonenal (4HNE) protein in the heart tissue, and reduced left ventricular ejection fraction (LVEF) when compared with the fed group. The CoPP group showed significantly increased protein levels of nuclear factor-erythroid 2-related factor 2 and HO-1, and increased mRNA expression levels of HO-1, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, forkhead box protein O1, sirtuin-1, cyclooxygenase 2, and superoxide dismutase 2, and reduced levels of heme and 4HNE protein when compared with the fasting group. LVEF were significantly higher in the CoPP group than in the fasting group.

CONCLUSIONS

Administration of CoPP reduced heme accumulation and oxidative stress, and ameliorated cardiac systolic dysfunction in long-term fasting mice. This study suggests that heme accumulation may be associated with impaired cardiac function induced by long-term fasting and that HO-1 may be a key factor or therapeutic target.

Daphnetin alleviates silica-induced pulmonary inflammation and fibrosis by regulating the PI3K/AKT1 signaling pathway in mice

Silicosis is a hazardous occupational disease caused by inhalation of silica, characterized by persistent lung inflammation that leads to fibrosis and subsequent lung dysfunction. Moreover, the complex pathophysiology of silicosis, the challenges associated with early detection, and the unfavorable prognosis contribute to the limited availability of treatment options. Daphnetin (DAP), a natural lactone, has demonstrated various pharmacological properties, including anti-inflammatory, anti-fibrotic, and pulmonary protective effects. However, the effects of DAP on silicosis and its molecular mechanisms remain uncover. This study aimed to evaluate the therapeutic effects of DAP against pulmonary inflammation and fibrosis using a silica-induced silicosis mouse model, and investigate the potential mechanisms and targets through network pharmacology, proteomics, molecular docking, and cellular thermal shift assay (CETSA). Here, we found that DAP significantly alleviated silica-induced lung injury in mice with silicosis. The results of H&E staining, Masson staining, and Sirius red staining indicated that DAP effectively reduced the inflammatory response and collagen deposition over a 28-day period following lung exposure to silica. Furthermore, DAP reduced the number of TUNEL-positive cells, increased the expression levels of Bcl-2, and decreased the expression of Bax and cleaved caspase-3 in the mice with silicosis. More importantly, DAP suppressed the expression levels of NLRP3 signaling pathway-related proteins, including NLRP3, ASC, and cleaved caspase-1, thereby inhibiting silica-induced lung inflammation. Further studies demonstrated that DAP possesses the ability to inhibit the epithelial mesenchymal transition (EMT) induced by silica through the inhibition of the TGF-β1/Smad2/3 signaling pathway. The experimental results of proteomic analysis found that the PI3K/AKT1 signaling pathway was the key targets of DAP to alleviate lung injury induced by silica. DAP significantly inhibited the activation of the PI3K/AKT1 signaling pathway induced by silica in lung tissues. The conclusion was also verified by the results of molecular and CETSA. To further verify this conclusion, the activity of PI3K/AKT1 signaling pathway was inhibited in A549 cells using LY294002. When the A549 cells were pretreated with LY294002, the protective effect of DAP on silica-induced injury was lost. In conclusion, the results of this study suggest that DAP alleviates pulmonary inflammation and fibrosis induced by silica by modulating the PI3K/AKT1 signaling pathway, and holds promise as a potentially effective treatment for silicosis.

Imperatorin ameliorates kidney injury in diabetic mice by regulating the TGF-β/Smad2/3 signaling axis, epithelial-to-mesenchymal transition, and renal inflammation

Diabetic nephropathy (DN) is a serious concern in patients with diabetes mellitus. Prolonged hyperglycemia induces oxidative damage, chronic inflammation, and build-up of extracellular matrix (ECM) components in the renal cells, leading to kidney structural and functional changes. Imperatorin (IMP) is a naturally occurring furanocoumarin derivative with proven antioxidative and anti-inflammatory properties. We investigated whether IMP could improve DN and employed high glucose (HG)-induced HK-2 cells and high-fat diet-fed streptozotocin (HFD/STZ)-generated DN experimental model in C57BL/6 mice. In vitro, IMP effectively reduced the HG-activated reactive oxygen species generation, disturbance in the mitochondrial membrane potential (MMP) and epithelial-to-mesenchymal transition (EMT)-related markers, and the transforming growth factor (TGF)-β and collagen 1 expression in HK-2 cells. In vivo, we found an elevation of serum creatinine, kidney histology alterations, and collagen build-up in the kidneys of the DN control group. Also, we found an altered expression of EMT-related markers, upregulation of the TGF-β/Smad2/3 axis, and elevated pro-inflammatory molecules, TNF-α, IL-1β, IL-18 and phospho-NF-kB (p65) in the DN control group. IMP treatment did not significantly reduce the blood glucose level compared to the DN control group. However, IMP treatment effectively improved renal damage by ameliorating kidney histological changes and serum renal injury markers. IMP treatment restored renal antioxidants and exhibited anti-inflammatory effects in the kidneys. Moreover, the abnormal manifestation of EMT-related attributes and elevated levels of TGF-β, phospho-Smad2/3, and collagen 1 were also normalized in the IMP treatment group. Our findings highlight that IMP may be a potential candidate for treating DN.

Exogenous Nucleotides Ameliorate Age-Related Decline in Testosterone in Male Senescence-Accelerated Mouse Prone-8 (SAMP8) Mice by Modulating the Local Renin-Angiotensin System Antioxidant Pathway

In older men, an age-related decline in testosterone is closely associated with various adverse health outcomes. With the progression of aging, hyperactivation of the local renin-angiotensin system (RAS) and oxidative stress increase in the testis. The regulation of RAS antioxidants may be a target to delay testicular aging and maintain testosterone levels. Exogenous nucleotides (NTs) have anti-aging potential in several systems, but there are no studies of their effects on the reproductive system. In our study, we examined the effects of exogenous NTs on testosterone synthesis and explored possible mechanisms of action. Therefore, senescence-accelerated mouse prone-8 (SAMP8) mice and senescence-accelerated mouse resistant 1 (SAMR1) were used in the experiment, and they were randomly divided into an NTs free group (NTs-F), a normal control group (control), a low-dose NTs group (NTs-L), a middle-dose NTs (NTs-M), a high-dose NTs group (NTs-H) and SAMR1 groups, and the testis of the mice were collected for testing after 9 months of intervention. The results showed that exogenous NTs could increase the testicular organ index in mice during aging, and delayed the age-associated decline in testosterone levels in SAMP8 male mice, possibly by modulating the local RAS antioxidant pathway and reducing oxidative stress to protect the testis. The present study provides new research clues for the development of preventive and therapeutic strategies for related diseases.

RNF13 protects against pathological cardiac hypertrophy through p62-NRF2 pathway

Heart failure (HF) severely impairs human health because of its high incidence and mortality. Cardiac hypertrophy is the main cause of HF, while its underlying mechanism is not fully clear. As an E3 ubiquitin ligase, Ring finger protein 13 (RNF13) plays a crucial role in many disorders, such as liver immune, neurological disease and tumorigenesis, whereas the function of RNF13 in cardiac hypertrophy remains largely unknown. In the present study, we found that the protein expression of RNF13 is up-regulated in the transverse aortic constriction (TAC)-induced murine hypertrophic hearts and phenylephrine (PE)-induced cardiomyocyte hypertrophy. Functional investigations indicated that RNF13 global knockout mice accelerates the degree of TAC-induced cardiac hypertrophy, including cardiomyocyte enlargement, cardiac fibrosis and heart dysfunction. On the contrary, adeno-associated virus 9 (AAV9) mediated-RNF13 overexpression mice alleviated cardiac hypertrophy. Furthermore, we demonstrated that adenoviral RNF13 attenuates the PE-induced cardiomyocyte hypertrophy and down-regulates the expression of cardiac hypertrophic markers, while the opposite results were observed in the RNF13 knockdown group. The RNA-sequence of RNF13 knockout and wild type mice showed that RNF13 deficiency activates oxidative stress after TAC surgery. In terms of the mechanism, we found that RNF13 directly interacted with p62 and promoted the activation of downstream NRF2/HO-1 signaling. Finally, we proved that p62 knockdown can reverse the effect of RNF13 in cardiac hypertrophy. In conclusion, RNF13 protects against the cardiac hypertrophy via p62-NRF2 axis.

Transforming growth factor-β and bone morphogenetic protein signaling pathways in pathological cardiac hypertrophy

Pathological cardiac hypertrophy (referred to as cardiac hypertrophy) is a maladaptive response of the heart to a variety of pathological stimuli, and cardiac hypertrophy is an independent risk factor for heart failure and sudden death. Currently, the treatments for cardiac hypertrophy are limited to improving symptoms and have little effect. Elucidation of the developmental process of cardiac hypertrophy at the molecular level and the identification of new targets for the treatment of cardiac hypertrophy are crucial. In this review, we summarize the research on multiple active substances related to the pathogenesis of cardiac hypertrophy and the signaling pathways involved and focus on the role of transforming growth factor-β (TGF-β) and bone morphogenetic protein (BMP) signaling in the development of cardiac hypertrophy and the identification of potential targets for molecular intervention. We aim to identify important signaling molecules with clinical value and hope to help promote the precise treatment of cardiac hypertrophy and thus improve patient outcomes.

Preparation, characterization, and antioxidant and antiapoptotic activities of biosynthesized nano‑selenium by yak-derived Bacillus cereus and chitosan-encapsulated chemically synthesized nano‑selenium

Nano‑selenium (SeNPs) is a red elemental selenium with extremely small particles, which can be absorbed by the body and has biological activity. Currently, the most commonly used synthetic methods for SeNPs are biosynthesis and chemical synthesis. In this study, YC-3-SeNPs were biosynthesized by a strain of yak-gut Bacillus cereus YC-3, and meanwhile, CST-SeNPs were chemically synthesized and encapsulated with chitosan. A series of characterizations proved that YC-3-SeNPs and CST-SeNPs are spherical particles with excellent stability, and both have an excellent ability to scavenge free radicals in vitro. The particles of YC-3-SeNPs were encapsulated with polysaccharides, fiber, and protein, and it was less toxic than that of CST-SeNPs. Additionally, YC-3-SeNPs and CST-SeNPs may inhibit H₂O₂-induced oxidative stress in cardiomyocytes by activating the Keap1/Nrf2/HO-1 signaling pathway thereby scavenging ROS. Meanwhile, they may exert anti-apoptotic activity in cardiomyocytes by stabilizing mitochondrial membrane potential (∆Ψm) and balancing Bax/Bcl-2 protein, thereby reducing the protein expression of Cyt-c and Cleaved-caspase 3. Given the above, YC-3-SeNPs and CST-SeNPs with excellent antioxidant and anti-apoptotic activities may have broad application potential in the field of cardiovascular diseases.

Anti-inflammatory activity of carvacrol protects the heart from lipopolysaccharide-induced cardiac dysfunction by inhibiting pyroptosis via NLRP3/Caspase1/Gasdermin D signaling axis

AIMS

Lipopolysaccharide (LPS) is a well-known agent to induce septic conditions. Sepsis-induced cardiomyopathy has an overwhelming death rate. Carvacrol (CVL), a monoterpene phenol, has anti-inflammatory and antioxidant properties. The research aimed to investigate the effect of CVL on LPS-induced dysfunction in the heart. In this study, we evaluated the effect of CVL in LPS-stimulated H9c2 cardiomyoblast cells and Balb/c mice.

MAIN METHODS

LPS was used to induce septic conditions in H9c2 cardiomyoblast cells in vitro and in Balb/C mice. A survival study was conducted to assess the survival rate of mice after LPS and/or CVL treatment.

KEY FINDINGS

In vitro studies indicated that CVL inhibits reactive oxygen species (ROS) generation and abates pyroptosis mediated by NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in H9c2 cells. In mice, CVL intervention improved the survival rate in septic conditions. The CVL administration markedly improved the echocardiographic parameters and alleviated the LPS-induced reduction in the ejection fraction (%) and fraction shortening (%). The CVL intervention restored the myocardial antioxidants and histopathological alterations and decreased the pro-inflammatory cytokine contents in the heart. Further findings disclosed that CVL reduced the protein levels of NLRP3, apoptosis-associated speck-like protein (ASC), caspase 1, interleukin (IL)-18, IL-1β, and the pyroptosis-indicative protein, gasdermin-D (GSDMD) in the heart. The autophagy-indicative proteins, beclin 1, and p62, in the heart were also restored in the CVL-treated group.

SIGNIFICANCE

Altogether, our findings demonstrated that CVL has a beneficial effect and can be a potential molecule against sepsis-induced myocardial dysfunction.

Anti-oxidant and anti-inflammatory effects of ellagic and punicic acid in an in vitro model of cardiac fibrosis

Cardiac fibrosis is a pathological process characterized by an excessive deposition of extracellular matrix (ECM) and an increased production of fibrillar collagen in the cardiac interstitium, mainly caused by the activation of cardiac fibroblasts and their transition into myofibroblasts. Oxidative stress is deeply implicated in the pathogenesis of cardiac fibrosis both directly and via its involvement in the tumor growth factor β1 (TGF-β1) signaling. Ellagic acid (EA) and punicic acid (PA) are the main components of the Punica granatum L (pomegranate) fruit and seed oil respectively, whose antioxidant, anti-inflammatory and anti-fibrotic effects have been previously described. Therefore, the aim of this study was to investigate the effects of EA or PA or EA+PA in an in vitro model of cardiac fibrosis. Immortalized Human Cardiac Fibroblasts (IM-HCF) were stimulated with 10 ng/ml of TGF-β1 for 24 h to induce a fibrotic damage. Cells were then treated with EA (1 µM), PA (1 µM) or EA+PA for additional 24 h. Both EA and PA reduced the pro-fibrotic proteins expressions and the intracellular reactive oxygen species (ROS) accumulation. The anti-oxidant activity was also observed by Nrf2 activation with the consequent TGF-β1-Smad2/3-MMP2/9 and Wnt/β-catenin signaling inhibition, thus reducing collagen production. EA and PA significantly inhibit NF-κB pathway and, consequently, TNF-α, IL-1β and IL-6 levels: the greater effect was observed when EA and PA were used in combination. These results suggest that EA, PA and in particular EA+PA might be effective in reducing fibrosis through their antioxidant and anti-inflammatory properties by the modulation of different molecular pathways.

Natural Coumarin Derivatives Activating Nrf2 Signaling Pathway as Lead Compounds for the Design and Synthesis of Intestinal Anti-Inflammatory Drugs

Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor related to stress response and cellular homeostasis that plays a key role in maintaining the redox system. The imbalance of the redox system is a triggering factor for the initiation and progression of non-communicable diseases (NCDs), including Inflammatory Bowel Disease (IBD). Nrf2 and its inhibitor Kelch-like ECH-associated protein 1 (Keap1) are the main regulators of oxidative stress and their activation has been recognized as a promising strategy for the treatment or prevention of several acute and chronic diseases. Moreover, activation of Nrf2/keap signaling pathway promotes inhibition of NF-κB, a transcriptional factor related to pro-inflammatory cytokines expression, synchronically promoting an anti-inflammatory response. Several natural coumarins have been reported as potent antioxidant and intestinal anti-inflammatory compounds, acting by different mechanisms, mainly as a modulator of Nrf2/keap signaling pathway. Based on in vivo and in vitro studies, this review focuses on the natural coumarins obtained from both plant products and fermentative processes of food plants by gut microbiota, which activate Nrf2/keap signaling pathway and produce intestinal anti-inflammatory activity. Although gut metabolites urolithin A and urolithin B as well as other plant-derived coumarins display intestinal anti-inflammatory activity modulating Nrf2 signaling pathway, in vitro and in vivo studies are necessary for better pharmacological characterization and evaluation of their potential as lead compounds. Esculetin, 4-methylesculetin, daphnetin, osthole, and imperatorin are the most promising coumarin derivatives as lead compounds for the design and synthesis of Nrf2 activators with intestinal anti-inflammatory activity. However, further structure-activity relationships studies with coumarin derivatives in experimental models of intestinal inflammation and subsequent clinical trials in health and disease volunteers are essential to determine the efficacy and safety in IBD patients.

Nuciferine alleviates intestinal inflammation by inhibiting MAPK/NF-κB and NLRP3/Caspase 1 pathways in vivo and in vitro

Nuciferine (NCF) is an aporphine alkaloid and a principal bioactive constituent in the lotus plant. Herewith, we investigated the potential anti-inflammatory effect and underlying mechanisms of NCF employing dextran sulfate sodium (DSS)-induced ulcerative colitis in mice, a predominant intestinal inflammatory disease, and mouse RAW 264.7 cells in vitro. Lipopolysaccharide (LPS) was used to generate an inflammatory response in the RAW 264.7 cells. The disease activity index (DAI), colon morphology, colonoscopy, and colon histopathology were performed to assess experimental colitis. The biochemical assays, enzyme-linked immunosorbent assay (ELISA), and immunoblot analysis were performed to understand the underlying mechanisms. In RAW 264.7 cells, NCF pretreatment significantly decreased the expression of inducible nitric oxide synthase (iNOS), the expression and release of pro-inflammatory cytokines including interleukin (IL)-1β, IL-18, and tumor necrosis factor-α (TNF-α) and interfered with the activation of mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), and NOD-like family pyrin domain containing 3 (NLRP3) signaling pathways. The oral treatment of NCF substantially alleviated the DSS-induced DAI, increased colon length, and restored colon morphology and histology. Compared to the DSS-induced mice, the proteins involved in the activation of MAPK/NF-κB/NLRP3 pathways and the cytokines were markedly decreased in the NCF-treated mice. Moreover, the tight junction architecture of the colon was well-maintained in NCF treatment groups by regulating the expression of claudin-1 and zonula occludens-1 (ZO-1) proteins. All these findings suggest that NCF can be a promising molecule to modulate ulcerative colitis.

Induction of Cardiac Pathology: Endogenous versus Exogenous Nrf2 Upregulation

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of the endogenous antioxidant response to reactive oxygen species as well as a controller of Phase II detoxification in response to xenobiotics. This amenity to specific external manipulation exploits the binding affinity of Nrf2 for its constitutive repressor and degradation facilitator Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1 (Keap1). Derived from both natural and synthesized origins, these compounds have been extensively tested without definitive beneficial results. Unfortunately, multiple terminated trials have shown a negative side to Nrf2 with regard to cardiac pathologies while animal-based studies have demonstrated cardiomyocyte hypertrophy and heart failure after chronic Nrf2 upregulation. Putatively based on autophagic control of Nrf2 activity-modulating upstream factors, new evidence of miRNA involvement has added complexity to this mechanism. What follows is an extensive survey of Nrf2-regulating exogenous compounds that may promote cardiomyopathy, clinical trial evidence, and a comparison to exercise-induced factors that also upregulate Nrf2 while preventing cardiac pathologies.

Daphnetin Alleviates Senile and Disuse Osteoporosis by Distinct Modulations of Bone Formation and Resorption

Senile and disuse osteoporosis have distinct bone turnover status and lack effective treatments. In this study, senescence-accelerated mouse prone 8 (SAMP8) and hindlimb unloading mouse models were used to explore the protective effects of daphnetin on these two types of osteoporosis, and primary osteoblasts and bone marrow monocyte-derived osteoclasts, as well as pre-osteoblast MC3T3-E1, and osteoclast precursor RAW264.7 cells were used to investigate the underlying mechanisms. The results showed that daphnetin administration effectively improved bone remodeling in both senile and disuse osteoporosis, but with different mechanisms. In senile osteoporosis with low bone turnover, daphnetin inhibited NOX2-mediated ROS production in osteoblasts, resulting in accelerated osteogenic differentiation and bone formation, while in disuse osteoporosis with high bone turnover, daphnetin restored SIRT3 expression, maintained mitochondrial homeostasis, and additionally upregulated SOD2 to eliminate ROS in osteoclasts, resulting in attenuation of osteoclast differentiation and bone resorption. These findings illuminated that daphnetin has promising potential for the prevention and treatment of senile and disuse osteoporosis. The different mechanisms may provide clues and basis for targeted prevention and treatment of osteoporosis according to distinct bone turnover status.

Carvacrol preserves antioxidant status and attenuates kidney fibrosis via modulation of TGF-β1/Smad signaling and inflammation

Chronic kidney disease (CKD) with diverse aetiologies is emerging as a challenging kidney disorder associated with inflammation and interstitial fibrosis. Carvacrol (CVL) is a bioactive monoterpenoid found abundantly in oregano, thyme, and bergamot, having diverse pharmacological benefits. However, the effect of CVL against fibrotic changes in the kidneys is poorly defined. In the current study, a robust mouse model of renal fibrosis induced through unilateral ureteral obstruction (UUO) is used to investigate the anti-fibrotic activity of CVL. The mice were treated with two different oral doses of CVL (25 mg kg^-1 and 50 mg kg^-1 body weight) for 14 consecutive days. The UUO induction resulted in impaired renal function, severe histological damage, and collagen deposition in the obstructed kidney. Our findings revealed profound activation of transforming growth factor-β1 (TGF-β1) and NF-κB (p65) signaling along with the downregulation of antioxidant proteins, nuclear factor-erythroid factor 2-related factor 2 (Nrf2), NAD(P)H: quinone oxidoreductase 1 (NQO1), and superoxide dismutase (SOD) in the obstructed kidney. CVL administration markedly recovered antioxidant proteins and kidney histological changes. In addition, CVL blunted the NF-κB (p65) phosphorylation and reduced the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and cyclooxygenase 2 (COX-2) compared to the UUO control group. CVL also alleviated the increased fibrotic protein levels of TGF-β1, pSmad2/3, collagen I, collagen III, fibronectin, and myofibroblast activation and epithelial-mesenchymal transition (EMT) markers, including alpha-smooth muscle actin (α-SMA), E-cadherin, and vimentin in the kidneys. Findings from in vitro study also confirmed that CVL inhibits the EMT process in TGF-β1 stimulated renal tubular epithelial cells (NRK 52E cells). Collectively, our findings indicate that CVL administration attenuates kidney fibrosis by targeting oxidative stress and inflammation.