Endothelial ERG alleviates cardiac fibrosis via blocking endothelin-1-dependent paracrine mechanism

Research trends and hotspots of circular RNA in cardiovascular disease: A bibliometric analysis

From a global perspective, cardiovascular diseases (CVDs), the leading factor accounting for population mortality, and circRNAs, RNA molecules with stable closed-loop structures, have been proven to be closely related. The latent clinical value and the potential role of circRNAs in CVDs have been attracting increasing, active research interest, but bibliometric studies in this field are still lacking. Thus, in this study, we conducted a bibliometric analysis by using software such as VOSviewer, CiteSpace, Microsoft Excel, and the R package to determine the current research progress and hotspots and ultimately provide an overview of the development trends and future frontiers in this field. In our study, based on our search strategy, a total of 1206 publications published before July 31, 2023 were accessed from the WOSCC database. According to our findings, there is a notable increasing trend in global publications in the field of circRNA in CVDs. China was found to be the dominant country in terms of publication number, but a lack of high-quality articles was a significant fault. A cluster analysis on the co-cited references indicated that dilated cardiomyopathy, AMI, and cardiac hypertrophy are the greatest objects of concern. In contrast, a keywords analysis indicated that high importance has been ascribed to MI, abdominal aortic aneurysm, cell proliferation, and coronary artery diseases.

Boldine prevents the inflammatory response of cardiac fibroblasts induced by SGK1-NFκB signaling pathway activation

Cardiac fibroblasts (CF) are mesenchymal-type cells responsible for maintaining the homeostasis of the heart's extracellular matrix (ECM). Their dysfunction leads to excessive secretion of ECM proteins, tissue stiffening, impaired nutrient and oxygen exchange, and electrical abnormalities in the heart. Additionally, CF act as sentinel cells in the cardiac tissue microenvironment, responding to various stimuli that may affect heart function. Deleterious stimuli induce an inflammatory response in CF, increasing the secretion of cytokines such as IL-1β and TNF-α and the expression of cell adhesion molecules like ICAM1 and VCAM1, initially promoting damage resolution by recruiting immune cells. However, constant harmful stimuli lead to a chronic inflammatory process and heart dysfunction. Therefore, it is necessary to study the mechanisms that govern CF inflammation. NFκB is a key regulator of the cardiac inflammatory process, making the search for mechanisms of NFκB regulation and CF inflammatory response crucial for developing new treatment options for cardiovascular diseases. SGK1, a serine-threonine protein kinase, is one of the regulators of NFκB and is involved in the fibrotic effects of angiotensin II and aldosterone, as well as in CF differentiation. However, its role in the CF inflammatory response is unknown. On the other hand, many bioactive natural products have demonstrated anti-inflammatory effects, but their role in CF inflammation is unknown. One such molecule is boldine, an alkaloid obtained from Boldo (Peumus boldus), a Chilean endemic tree with proven cytoprotective effects. However, its involvement in the regulation of SGK1 and CF inflammation is unknown. In this study, we evaluated the role of SGK1 and boldine in the inflammatory response in CF isolated from neonatal Sprague-Dawley rats. The involvement of SGK1 was analyzed using GSK650394, a specific SGK1 inhibitor. Our results demonstrate that SGK1 is crucial for LPS- and IFN-γ-induced inflammatory responses in CF (cytokine expression, cell adhesion molecule expression, and leukocyte adhesion). Furthermore, a conditioned medium (intracellular content of CF subject to freeze/thaw cycles) was used to simulate a sterile inflammation condition. The conditioned medium induced a potent inflammatory response in CF, which was completely prevented by the SGK1 inhibitor. Finally, our results indicate that boldine inhibits both SGK1 activation and the CF inflammatory response induced by LPS, IFN-γ, and CF-conditioned medium. Taken together, our results position SGK1 as an important regulator of the CF inflammatory response and boldine as a promising anti-inflammatory drug in the context of cardiovascular diseases.

LDHA contributes to nicotine induced cardiac fibrosis through autophagy flux impairment

Cardiac fibrosis is a typical feature of cardiac pathological remodeling, which is associated with adverse clinical outcomes and has no effective therapy. Nicotine is an important risk factor for cardiac fibrosis, yet its underlying molecular mechanism remains poorly understood. This study aimed to identify its potential molecular mechanism in nicotine-induced cardiac fibrosis. Our results showed nicotine exposure led to the proliferation and transformation of cardiac fibroblasts (CFs) into myofibroblasts (MFs) by impairing autophagy flux. Through the use of drug affinity responsive target stability (DARTS) assay, cellular thermal shift assay (CETSA), and surface plasmon resonance (SPR) technology, it was discovered that nicotine directly increased the stability and protein levels of lactate dehydrogenase A (LDHA) by binding to it. Nicotine treatment impaired autophagy flux by regulating the AMPK/mTOR signaling pathway, impeding the nuclear translocation of transcription factor EB (TFEB), and reducing the activity of cathepsin B (CTSB). In vivo, nicotine treatment exacerbated cardiac fibrosis induced in spontaneously hypertensive rats (SHR) and worsened cardiac function. Interestingly, the absence of LDHA reversed these effects both in vitro and in vivo. Our study identified LDHA as a novel nicotine-binding protein that plays a crucial role in mediating cardiac fibrosis by blocking autophagy flux. The findings suggest that LDHA could potentially serve as a promising target for the treatment of cardiac fibrosis.

The NEDD8 activating enzyme inhibitor MLN4924 mitigates doxorubicin-induced cardiotoxicity in mice

Doxorubicin (DOX) is a widely utilized chemotherapeutic agent in clinical oncology for treating various cancers. However, its clinical use is constrained by its significant side effects. Among these, the development of cardiomyopathy, characterized by cardiac remodeling and eventual heart failure, stands as a major concern following DOX chemotherapy. In our current investigation, we have showcased the efficacy of MLN4924 in mitigating doxorubicin-induced cardiotoxicity through direct inhibition of the NEDD8-activating enzyme, NAE. MLN4924 demonstrated the ability to stabilize mitochondrial function post-doxorubicin treatment, diminish cardiomyocyte apoptosis, alleviate oxidative stress-induced damage in the myocardium, enhance cardiac contractile function, mitigate cardiac fibrosis, and impede cardiac remodeling associated with heart failure. At the mechanistic level, MLN4924 intervened in the neddylation process by inhibiting the NEDD8 activating enzyme, NAE, within the murine cardiac tissue subsequent to doxorubicin treatment. This intervention resulted in the suppression of NEDD8 protein expression, reduction in neddylation activity, and consequential manifestation of cardioprotective effects. Collectively, our findings posit MLN4924 as a potential therapeutic avenue for mitigating doxorubicin-induced cardiotoxicity by attenuating heightened neddylation activity through NAE inhibition, thereby offering a viable and promising treatment modality for afflicted patients.

Lapatinib combined with doxorubicin causes dose-dependent cardiotoxicity partially through activating the p38MAPK signaling pathway in zebrafish embryos

Because of its enhanced antitumor efficacy, lapatinib (LAP) is commonly used clinically in combination with the anthracycline drug doxorubicin (DOX) to treat metastatic breast cancer. While it is well recognized that this combination chemotherapy can lead to an increased risk of cardiotoxicity in adult women, its potential cardiotoxicity in the fetus during pregnancy remains understudied. Here, we aimed to examine the combination of LAP chemotherapy and DOX-induced cardiotoxicity in the fetus using a zebrafish embryonic system and investigate the underlying pathologic mechanisms. First, we examined the dose-dependent cardiotoxicity of combined LAP and DOX exposure in zebrafish embryos, which mostly manifested as pericardial edema, bradycardia, cardiac function decline and reduced survival. Second, we revealed that a significant increase in oxidative stress concurrent with activated MAPK signaling, as indicated by increased protein expression of phosphorylated p38 and Jnk, was a notable pathophysiological event after combined LAP and DOX exposure. Third, we showed that inhibiting MAPK signaling by pharmacological treatment with the p38MAPK inhibitor SB203580 or genetic ablation of the map2k6 gene could significantly alleviate combined LAP and DOX exposure-induced cardiotoxicity. Thus, we provided both pharmacologic and genetic evidence to suggest that inhibiting MAPK signaling could exert cardioprotective effects. These findings have implications for understanding the potential cardiotoxicity induced by LAP and DOX combinational chemotherapy in the fetus during pregnancy, which could be leveraged for the development of new therapeutic strategies.

Matrine attenuating cardiomyocyte apoptosis in doxorubicin-induced cardiotoxicity through improved mitochondrial membrane potential and activation of mitochondrial respiratory chain Complex I pathway

The study aimed to demonstrate that matrine can reduce apoptosis in H9c2 cells induced by the cardiotoxic anticancer drug doxorubicin (DOX).The researchers pretreated H9c2 cells with different concentrations of matrine before exposing them to DOX and cultured them for 24 h. They assessed cell survival rates using cell counting kit-8 and MTT assay. Hoechst 33258 dye kits were used to determine apoptosis, while laser confocal JC-1 method was applied to test the mitochondrial membrane potential (MMP). Complex I activities were detected following the manufacturer's protocol. The results indicated that matrine pretreatment significantly increased the survival rate of H9c2 cells injured by DOX. Additionally, matrine reduced apoptosis in H9c2 cells through the improvement of MMP and activity of Complex I, which were damaged by DOX.

CYP2J2-derived epoxyeicosatrienoic acids protect against doxorubicin-induced cardiotoxicity by reducing oxidative stress and apoptosis via activation of the AMPK pathway

Objective

Despite the widespread use of doxorubicin (DOX) in chemotherapy, it can cause cardiotoxicity, which severely limits its potential clinical use. CYP2J2-derived epoxyeicosatrienoic acids (EETs) exert cardioprotective effects by maintaining cardiac homeostasis. The roles and latent mechanisms of EETs in DOX cardiotoxicity remain uncertain. We investigated these aspects using mouse tissue and cell culture models.

Methods

C57BL/6J mice were injected with rAAV9-CYP2J2 or a control vector via the caudal vein. A five-week intraperitoneal course of DOX (5 mg/kg per week) was administered. After pretreatment with 14,15-EET, H9C2 cells were treated for 24-h with DOX, to use as a cell model to verify the role of EETs in cardiotoxicity in vitro.

Results

CYP2J2 overexpression mitigated DOX-induced cardiotoxicity, as shown by the diminished cardiac injury marker levels, improved heart function, reduced oxidative stress, and inhibition of myocardial apoptosis in vivo. These protective roles are associated with the enhancement of antioxidant and anti-apoptotic abilities and the activation of the AMPK pathway. 14,15-EET suppresses DOX-induced oxidative stress, mitochondrial dysfunction, and apoptosis in H9C2 cells. AMPK knockdown partially abolished the cardioprotective effects of 14,15-EET against oxidative damage and apoptosis in DOX-treated cells, suggesting that AMPK is responsible for EET-mediated protection against cardiotoxicity.

Conclusion

CYP2J2-derived EETs confer myocardial protection against DOX-induced toxicity by activating the AMPK pathway, which reduces oxidative stress, mitochondrial dysfunction, and apoptosis.

Inhibition of ferroptosis by POLE2 in gastric cancer cells involves the activation of NRF2/GPX4 pathway

Gastric cancer results in great cancer mortality worldwide, and inducing ferroptosis dramatically improves the malignant phenotypes of gastric cancer. DNA polymerase epsilon subunit 2 (POLE2) plays indispensable roles in tumorigenesis; however, its involvement and molecular basis in ferroptosis and gastric cancer are not clear. Human gastric cancer cells were infected with lentiviral vectors to knock down or overexpress POLE2, and cell ferroptosis was detected. To further validate the involvement of nuclear factor erythroid 2-related factor 2 (NRF2) and glutathione peroxidase 4 (GPX4), lentiviral vectors were used. POLE2 expression was elevated in human gastric cancer cells and tissues and closely correlated with clinicopathological features in gastric cancer patients. POLE2 knockdown was induced, while POLE2 overexpression inhibited ferroptosis of human gastric cancer cells, thereby modulating the malignant phenotypes of gastric cancer. Mechanistic studies revealed that POLE2 overexpression elevated NRF2 expression and activity and subsequently activated GPX4, which then prevented lipid peroxidation and ferroptosis in human gastric cancer cells. In contrast, either NRF2 or GPX4 silence significantly prevented POLE2 overexpression-mediated inductions of cell proliferation, migration, invasion and inhibition of ferroptosis. POLE2 overexpression inhibits ferroptosis in human gastric cancer cells through activating NRF2/GPX4 pathway, and inhibiting POLE2 may be a crucial strategy to treat gastric cancer.

PKD knockdown mitigates Ang II-induced cardiac hypertrophy and ferroptosis via the JNK/P53 signaling pathway

BACKGROUND

Cardiac hypertrophy is studied in relation to energy metabolism, autophagy, and ferroptosis, which are associated with cardiovascular adverse events and chronic heart failure. Protein kinase D (PKD) has been shown to play a degenerative role in cardiac hypertrophy. However, the role of ferroptosis in PKD-involved cardiac hypertrophy remains unclear.

METHODS

A cardiac hypertrophy model was induced by a subcutaneous injection of angiotensin II (Ang II) for 4 weeks. Adeno-associated virus serotype 9 (AAV9)-PKD or AAV9-Negative control were injected through the caudal vein 2 weeks prior to the injection of Ang II. The degree of cardiac hypertrophy was assessed using echocardiography and by observing cardiomyocyte morphology. Levels of ferroptosis and protein expression in the Jun N-terminal kinase (JNK)/P53 signaling pathway were measured both in vivo and in vitro.

RESULTS

The results indicated that PKD knockdown reduces Ang II-induced cardiac hypertrophy, enhances cardiac function and inhibits ferroptosis. The involvement of the JNK/P53 pathway in this process was further confirmed by in vivo and in vitro experiments.

CONCLUSION

In conclusion, our findings suggest that PKD knockdown mitigates Ang II-induced cardiac hypertrophy and ferroptosis via the JNK/P53 signaling pathway.

CD11b mediates hypertensive cardiac remodeling by regulating macrophage infiltration and polarization

INTRODUCTION

Leukocyte infiltration is an early event during cardiac remodeling frequently leading to heart failure (HF). Integrins mediate leukocyte infiltration during inflammation. However, the importance of specific integrins in hypertensive cardiac remodeling is still unclear.

OBJECTIVES

To elucidate the significance of CD11b in hypertensive cardiac remodeling.

METHODS

Angiotensin (Ang II) or deoxycorticosterone acetate (DOCA)-salt was used to induce cardiac remodeling in mice of gene knockout (KO), bone marrow (BM) chimera, and the CD11b neutralizing antibody or agonist leukadherin-1 (LA1) treatment.

RESULTS

Our microarray data showed that integrin subunits Itgam (CD11b) and Itgb2 (CD18) were the most highly upregulated in Ang II-infused hearts. CD11b expression and CD11b/CD18+ myelomonocytes were also time-dependently increased. KO or pharmacological blockade of CD11b greatly attenuated cardiac remodeling and macrophage infiltration and M1 polarization induced by Ang II or DOCA-salt. This protection was verified in wild-type mice transplanted with CD11b-deficient BM cells. Conversely, administration of CD11b agonist LA1 showed the opposite effects. Further, CD11b KO reduced Ang II-induced macrophage adhesion and M1 polarization, leading to reduction of cardiomyocyte enlargement and fibroblast differentiation in vitro. The numbers of CD14+CD11b+CD18+ monocytes and CD15+CD11b+CD18+ granulocytes were obviously higher in HF patients than in normal controls.

CONCLUSION

Our data demonstrate an important role of CD11b+ myeloid cells in hypertensive cardiac remodeling, and suggest that HF may benefit from targeting CD11b.

Deubiquitinase OTUB1 regulates doxorubicin-induced cardiotoxicity via deubiquitinating c-MYC

BACKGROUND

Doxorubicin (DOX), an anthracycline drug widely used in antitumor therapies, has dose-dependent toxicity that can cause cardiomyocyte apoptosis and oxidative stress, thus limiting its clinical application. OTUB1 (ovarian tumor associated proteinase B1) is an OTU superfamily deubiquitinase that effectively regulates cell proliferation, inflammatory responses, apoptosis, and oxidative stress by specifically removing K48- and K63-linked ubiquitination; however, its role in DOX-induced cardiotoxicity remains unknown.

MATERIALS AND METHODS

A DOX-induced subacute cardiotoxicity mouse model was established by intraperitoneal injection, and cardiac injury was assessed by echocardiography, serum cardiac markers, and histopathological staining. Western blotting, qRT-PCR, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) immunohistochemistry were used to analyze cell apoptosis, tissue oxidative stress was assessed by superoxide dismutase (SOD) activity, malondialdehyde (MDA), and glutathione peroxidase (GSH-PX) activity. Cell counting kit-8 (CCK-8) assay, TUNEL staining, Western blotting, qRT-PCR, and reactive oxygen species (ROS) flow cytometry were applied on isolated neonatal mice cardiomyocytes to assess apoptosis and oxidative stress. Differentially expressed genes were analyzed using RNA sequencing and clustering analyses. c-MYC inhibitor 10,058-F4 and siRNA targeting c-Myc were used to investigate the roles of c-MYC in OTUB1's regulations of DOX-induced cardiotoxicity. Immunoprecipitation and Western blotting were performed to reveal the deubiquitinating effects of OTUB1 on c-MYC expression.

RESULTS

We found that global Otub1-knockdown in vivo alleviated the subacute DOX treatment-induced cardiac dysfunction, fibrosis, and cardiomyocyte atrophy. Mechanistically, unbiased RNA sequencing and molecular biology experiments revealed that cardiomyocyte apoptosis, inflammation, and oxidative stress in DOX-induced cardiotoxicity were significantly compromised in the Otub1-knockdown group. Further in vitro studies have shown that c-MYC, a critical regulator of apoptosis, is indispensable in OTUB1's regulations of DOX-induced cardiotoxicity. Deubiquitinating effects of OTUB1 on K48- and K63-linked ubiquitination of c-MYC protein are essential for promoting cardiomyocyte apoptosis and oxidative responses.

CONCLUSIONS

OTUB1-c-MYC inhibition protected cardiomyocytes against DOX-induced apoptosis and oxidative stress, suggesting that OTUB1 is a potential translational therapeutic target for preventing DOX-induced cardiotoxicity.

Growth differentiation factor 7 pretreatment enhances the therapeutic capacity of bone marrow-derived mesenchymal stromal cells against cerebral ischemia-reperfusion injury

Bone marrow-derived mesenchymal stem cells (BMSCs) transplantation is a promising therapeutic strategy for cerebral ischemia/reperfusion (I/R) injury; however, the clinical outcome is barely satisfactory and demands further improvement. The present study aimed to investigate whether preconditioning of BMSCs by recombinant human growth differentiation factor 7 (rhGDF7) could enhance its therapeutic capacity against cerebral I/R injury. Mouse BMSCs and primary neurons were co-cultured and exposed to oxygen glucose deprivation/reperfusion (OGD/R) stimulation. To investigate the role of exosomal microRNA-369-3p (miR-369-3p), inhibitors, RNAi and the miR-369-3p antagomir were used. Meanwhile, mice were intravenously injected with rhGDF7-preconditioned BMSCs and then received cerebral I/R surgery. Markers of inflammation, oxidative stress and neural damage were evaluated. To inhibit AMP-activated protein kinase (AMPK), compound C was used in vivo and in vitro. Compared with cell-free transwell or vehicle-preconditioned BMSCs, rhGDF7-preconditioned BMSCs significantly prevented OGD/R-induced inflammation, oxidative stress and neural damage in vitro. Meanwhile, rhGDF7-preconditioned BMSCs could prevent I/R-induced cerebral inflammation and oxidative stress in vivo. Mechanistically, rhGDF7 preconditioning significantly increased exosomal miR-369-3p expression in BMSCs and then transferred exosomal miR-369-3p to primary neurons, where it bound to phosphodiesterase 4 D (Pde4d) 3'-UTR and downregulated PDE4D expression, thereby preventing I/R-induced inflammation, oxidative stress and neural damage through activating AMPK pathway. Our study identify GDF7 pretreatment as a promising adjuvant reagent to improve the therapeutic potency of BMSCs for cerebral I/R injury and ischemic stroke.

Bisdemethoxycurcumin alleviates LPS-induced acute lung injury via activating AMPKα pathway

OBJECTIVE

Inflammation and oxidative stress contribute to the pathogenesis of acute lung injury (ALI), and subsequently result in rapid deterioration in health. Considering the indispensable role of bisdemethoxycurcumin (BDMC) in inflammation and oxidative stress, the present study aims to examine the effect of BDMC on sepsis-related ALI.

METHODS

C57BL/6 mice were administered with BDMC (100 mg/kg) or an equal volume of vehicle, and then injected with lipopolysaccharides (LPS) to induce ALI. We assessed the parameters of lung injury, inflammatory response and oxidative stress in lung tissues. Consistently, the macrophages with or without BDMC treatment were exposed to LPS to verify the effect of BDMC in vitro.

RESULTS

BDMC suppressed LPS-induced lung injury, inflammation and oxidative stress in vivo and in vitro. Mechanistically, BDMC increased the phosphorylation of AMPKα in response to LPS stimulation, and AMPK inhibition with Compound C almost completely blunted the protective effect of BDMC in LPS-treated mice and macrophages. Moreover, we demonstrated that BDMC activated AMPKα via the cAMP/Epac pathway.

CONCLUSION

Our study identifies the protective effect of BDMC against LPS-induced ALI, and the underlying mechanism may be related to the activation of cAMP/Epac/AMPKα signaling pathway.

Taxifolin protects against doxorubicin-induced cardiotoxicity and ferroptosis by adjusting microRNA-200a-mediated Nrf2 signaling pathway

The chemotherapeutic agent doxorubicin (Dox) is commonly used to treat various types of cancer, even though it can cause life-threatening cardiotoxicity. Clinically, there is no particularly effective way to treat Dox-induced cardiotoxicity. Therefore, it is imperative to identify compounds that can effectively alleviate Dox-induced cardiotoxicity. Ferroptosis and oxidative stress play a key role in Dox-induced cardiotoxicity, and the inhibition of ferroptosis and oxidative stress could effectively protect against doxorubicin-induced cardiotoxicity. Taxifolin (TAX) is a flavonoid commonly found in onions and citrus fruits. In the present study, we evaluated the effects of TAX on Dox-induced cardiac injury and dysfunction and aimed to explore the mechanisms underlying these effects. Using a mouse model of Dox-induced cardiotoxicity, we administered 20 mg/kg/day of TAX by gavage for 2 weeks. A week after the first use of TAX, each mouse was administered a 10 mg/kg dose of Dox. TAX was first evaluated for its cardioprotective properties, and the outcomes showed that TAX significantly reduced the damage caused by Dox to the myocardium in terms of structural and functional damage by effectively inhibiting ferroptosis and oxidative stress. In vivo, echocardiography, histopathologic assay, serum biochemical analysis and western blotting was used to find the results that Dox promoted ferroptosis-induced cardiomyocyte death, while TAX reversed these effects. In vitro, we also found that TAX alleviated Dox-induced cardiotoxicity by using ROS/DHE staining assay, Cellular immunofluorescence and western blotting. TAX increasing expression of microRNA-200a (miR-200a) which affects ferroptosis by activating Nrf2 signaling pathway. We believe that TAX inhibits ferroptosis and is a potential phytochemical that prevents Dox-induced cardiotoxicity.

Leucine zipper protein 1 attenuates pressure overload-induced cardiac hypertrophy through inhibiting Stat3 signaling

INTRODUCTION

Cardiac hypertrophy is an important contributor of heart failure, and the mechanisms remain unclear. Leucine zipper protein 1 (LUZP1) is essential for the development and function of cardiovascular system; however, its role in cardiac hypertrophy is elusive.

OBJECTIVES

This study aims to investigate the molecular basis of LUZP1 in cardiac hypertrophy and to provide a rational therapeutic approach.

METHODS

Cardiac-specific Luzp1 knockout (cKO) and transgenic mice were established, and transverse aortic constriction (TAC) was used to induce pressure overload-induced cardiac hypertrophy. The possible molecular basis of LUZP1 in regulating cardiac hypertrophy was determined by transcriptome analysis. Neonatal rat cardiomyocytes were cultured to elucidate the role and mechanism of LUZP1 in vitro.

RESULTS

LUZP1 expression was progressively increased in hypertrophic hearts after TAC surgery. Gain- and loss-of-function methods revealed that cardiac-specific LUZP1 deficiency aggravated, while cardiac-specific LUZP1 overexpression attenuated pressure overload-elicited hypertrophic growth and cardiac dysfunction in vivo and in vitro. Mechanistically, the transcriptome data identified Stat3 pathway as a key downstream target of LUZP1 in regulating pathological cardiac hypertrophy. Cardiac-specific Stat3 deletion abolished the pro-hypertrophic role in LUZP1 cKO mice after TAC surgery. Further findings suggested that LUZP1 elevated the expression of Src homology region 2 domain-containing phosphatase 1 (SHP1) to inactivate Stat3 pathway, and SHP1 silence blocked the anti-hypertrophic effects of LUZP1 in vivo and in vitro.

CONCLUSION

We demonstrate that LUZP1 attenuates pressure overload-induced cardiac hypertrophy through inhibiting Stat3 signaling, and targeting LUZP1 may develop novel approaches to treat pathological cardiac hypertrophy.

CNIH4 governs cervical cancer progression through reducing ferroptosis

Cervical cancer is one of the most leading causes of cancer death worldwide, and ferroptosis is implicated in the progression of cervical cancer. Cornichon family AMPA receptor auxiliary protein 4 (CNIH4) is involved in the progression of various human cancers; however, its function in cervical cancer remains unclear. The present study aims to investigate the role and mechanism of CNIH4 in cervical cancer using gain- and loss-of-function studies in vitro. SiHa and CaSki cells were infected with lentiviral vectors to manipulate the expression of CNIH4 in vitro, and cell viability, migration, invasion as well as ferroptosis were evaluated. Transcriptome sequencing analysis was performed to further validate the mechanism through which CNIH4 regulated the progression of cervical cancer. The expression of CNIH4 was upregulated in human cervical cancer tissues and cells, and strongly correlated with the decreases in overall survival and disease free survival rates of cervical cancer patients. CNIH4 silence inhibited, while CNIH4 overexpression facilitated the survival of human cervical cancer cells. Mechanistically, CNIH4 elevated solute carrier family 7 member 11 (SLC7A11)-mediated cystine import, and subsequently increased intracellular glutathione synthesis and glutathione peroxidase 4 activity, thereby inhibiting ferroptosis of human cervical cancer cells. SLC7A11 silence significantly abolished CNIH4-mediated inhibition of ferroptosis in cervical cancer cells in vitro. Our study for the first time reveals that CNIH4 inhibits ferroptosis of human cervical cancer cells through upregulating SLC7A11, defining CNIH4 as an attractive therapeutic and prognostic target for cervical cancer.

ANGPTL2 aggravates LPS-induced septic cardiomyopathy via NLRP3-mediated inflammasome in a DUSP1-dependent pathway

Angiopoietin-like protein 2 (ANGPTL2) was implicated in various cardiovascular diseases; however, its role in lipopolysaccharide (LPS)-related septic cardiomyopathy remains unclear. Herein, mice were exposed to LPS to generate septic cardiomyopathy, and adeno-associated viral vector was employed to overexpress ANGPTL2 in the myocardium. Besides, mice were treated with adenoviral vector to knock down ANGPTL2 in hearts. ANGPTL2 expressions in hearts and cardiomyocytes were upregulated by LPS challenge. ANGPTL2 overexpression aggravated, while ANGPTL2 silence ameliorated LPS-associated cardiac impairment and inflammation. Mechanically, we found that ANGPTL2 activated NLRP3 inflammasome via suppressing DUSP1 signaling, and NLRP3 knockdown abrogated the detrimental role of ANGPTL2 in aggravating LPS-induced cardiac inflammation. Furthermore, DUSP1 overexpression significantly inhibited ANGPTL2-mediated NLRP3 activation, and subsequently improved LPS-related cardiac dysfunction. In summary, ANGPTL2 exacerbated septic cardiomyopathy via activating NLRP3-mediated inflammation in a DUSP1-dependent manner, and our study uncovered a promising therapeutic target in preventing septic cardiomyopathy.

MEGF6 prevents sepsis-induced acute lung injury in mice

OBJECTIVE

Acute lung injury (ALI) is featured as excessive inflammatory response and oxidative damage, and results in high death rate of septic patients. This research intends to determine the function of multiple EGF like domains 6 (MEGF6) in sepsis-induced ALI.

METHODS

Mice were intratracheally treated with adenovirus to knock down or overexpress MEGF6 in lung tissues, and then were subjected to cecum ligation and puncture (CLP) operation to induce ALI. Primary peritoneal macrophages were isolated, and were knocked down or overexpressed with MEGF6, and then, were stimulated with lipopolysaccharide (LPS) to confirm its role in vitro.

RESULTS

Serum and lung MEGF6 levels were significantly elevated in septic mice. MEGF6 knockdown exacerbated, while MEGF6 overexpression prevented inflammation, oxidative damage and ALI in CLP mice. Meanwhile, LPS-elicited inflammatory response and oxidative damage in primary macrophages were reduced by MEGF6 overexpression, but were further aggravated by MEGF6 knockdown. Mechanistic studies revealed that MEGF6 reduced cluster of differentiation 38 (CD38) expression and subsequently elevated intracellular nicotinamide adenine dinucleotide levels, thereby activating sirtuin 1 (SIRT1) without affecting the protein expression. SIRT1 suppression or CD38 overexpression with either genetic or pharmacologic methods remarkably blunted the lung protective effects of MEGF6 in CLP mice.

CONCLUSION

MEGF6 prevents CLP-induced ALI through CD38/SIRT1 pathway, and it might be a valuable therapeutic candidate for the management of sepsis-induced ALI.

Peficitinib ameliorates doxorubicin-induced cardiotoxicity by suppressing cellular senescence and enhances its antitumor activity

Irreversible cardiotoxicity limits the clinical applications of doxorubicin (DOX). Cardiotoxicity can be detected early using clinical assessment; however, effective preventive measures are still lacking. Peficitinib (ASP015K), a JAK (Janus kinase) inhibitor, is a potent anti-inflammatory agent in autoimmune diseases. Nevertheless, little research has been conducted on anti-ageing and anti-tumour therapies. In this study, we investigated whether ASP015K could attenuate DOX-induced cardiotoxicity through its anti-ageing effects and whether it would affect the tumour treatment effect of DOX by establishing senescence, acute heart injury, and xenograft models. We observed that ASP015K could antagonise the senescence induced by various factors, including hydrogen peroxide and DOX. In addition, ASP015K treatment significantly alleviated cardiac function damage, histopathological deterioration, myocardial fibrosis, and oxidative damage in acute injury mouse models. ASP015K enhanced the sensitivity of tumour cells to DOX therapy and significantly slowed down the tumour growth rate and tumour volume in the xenograft mouse model. Therefore, ASP015K is expected to be developed as a potential cardioprotective agent to prevent or reduce the cardiotoxic side effects of anthracyclines in chemotherapy.

FLRT2 suppresses bladder cancer progression through inducing ferroptosis

Bladder cancer is a common tumour worldwide and exhibits a poor prognosis. Fibronectin leucine rich transmembrane protein 2 (FLRT2) is associated with the regulation of multiple tumours; however, its function in human bladder cancer remain unclear. Herein, we found that FLRT2 level was reduced in human bladder cancer and that higher FLRT2 level predicted lower survival rate. FLRT2 overexpression inhibited, while FLRT2 silence facilitated tumour cell growth, migration and invasion. Mechanistic studies revealed that FLRT2 elevated acyl-CoA synthetase long-chain family member 4 (ACSL4) expression, increased lipid peroxidation and subsequently facilitated ferroptosis of human bladder cancer cells. In summary, we demonstrate that FLRT2 elevates ACSL4 expression to facilitate lipid peroxidation and subsequently triggers ferroptosis, thereby inhibiting the malignant phenotype of human bladder cancer cells. Overall, we identify FLRT2 as a tumour suppressor gene.

Leucine zipper protein 1 prevents doxorubicin-induced cardiotoxicity in mice

OBJECTIVE

Doxorubicin (DOX) is commonly used for chemotherapy; however, its clinical value is extremely dampened because of the fatal cardiotoxicity. Leucine zipper protein 1 (LUZP1) plays critical roles in cardiovascular development, and this study is designed for determining its function and mechanism in DOX-induced cardiotoxicity.

METHODS

Cardiac-specific Luzp1 knockout (cKO) and transgenic (cTG) mice received a single or repeated DOX injections to establish acute and chronic cardiotoxicity. Biomarkers of inflammation, oxidative damage and cell apoptosis were evaluated. Transcriptome and co-immunoprecipitation analysis were used to screen the underlying molecular pathways. Meanwhile, primary cardiomyocytes were applied to confirm the beneficial effects of LUZP1 in depth.

RESULTS

LUZP1 was upregulated in DOX-injured hearts and cardiomyocytes. Cardiac-specific LUZP1 deficiency aggravated, while cardiac-specific LUZP1 overexpression attenuated DOX-associated inflammation, oxidative damage, cell apoptosis and acute cardiac injury. Mechanistic studies revealed that LUZP1 ameliorated DOX-induced cardiotoxicity through activating 5'-AMP-activated protein kinase (AMPK) pathway, and AMPK deficiency abolished the cardioprotection of LUZP1. Further findings suggested that LUZP1 interacted with protein phosphatase 1 to activate AMPK pathway. Moreover, we determined that cardiac-specific LUZP1 overexpression could also attenuate DOX-associated chronic cardiac injury in mice.

CONCLUSION

LUZP1 attenuates DOX-induced inflammation, oxidative damage, cell apoptosis and ventricular impairment through regulating AMPK pathway, and gene therapy targeting LUZP1 may provide novel therapeutic approached to treat DOX-induced cardiotoxicity.

Tisp40 prevents cardiac ischemia/reperfusion injury through the hexosamine biosynthetic pathway in male mice

The hexosamine biosynthetic pathway (HBP) produces uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) to facilitate O-linked GlcNAc (O-GlcNAc) protein modifications, and subsequently enhance cell survival under lethal stresses. Transcript induced in spermiogenesis 40 (Tisp40) is an endoplasmic reticulum membrane-resident transcription factor and plays critical roles in cell homeostasis. Here, we show that Tisp40 expression, cleavage and nuclear accumulation are increased by cardiac ischemia/reperfusion (I/R) injury. Global Tisp40 deficiency exacerbates, whereas cardiomyocyte-restricted Tisp40 overexpression ameliorates I/R-induced oxidative stress, apoptosis and acute cardiac injury, and modulates cardiac remodeling and dysfunction following long-term observations in male mice. In addition, overexpression of nuclear Tisp40 is sufficient to attenuate cardiac I/R injury in vivo and in vitro. Mechanistic studies indicate that Tisp40 directly binds to a conserved unfolded protein response element (UPRE) of the glutamine-fructose-6-phosphate transaminase 1 (GFPT1) promoter, and subsequently potentiates HBP flux and O-GlcNAc protein modifications. Moreover, we find that I/R-induced upregulation, cleavage and nuclear accumulation of Tisp40 in the heart are mediated by endoplasmic reticulum stress. Our findings identify Tisp40 as a cardiomyocyte-enriched UPR-associated transcription factor, and targeting Tisp40 may develop effective approaches to mitigate cardiac I/R injury.

Trends in worldwide research on cardiac fibrosis over the period 1989-2022: a bibliometric study

Background

Cardiac fibrosis is a hallmark of various end-stage cardiovascular diseases (CVDs) and a potent contributor to adverse cardiovascular events. During the past decades, extensive publications on this topic have emerged worldwide, while a bibliometric analysis of the current status and research trends is still lacking.

Methods

We retrieved relevant 13,446 articles on cardiac fibrosis published between 1989 and 2022 from the Web of Science Core Collection (WoSCC). Bibliometrix was used for science mapping of the literature, while VOSviewer and CiteSpace were applied to visualize co-authorship, co-citation, co-occurrence, and bibliographic coupling networks.

Results

We identified four major research trends: (1) pathophysiological mechanisms; (2) treatment strategies; (3) cardiac fibrosis and related CVDs; (4) early diagnostic methods. The most recent and important research themes such as left ventricular dysfunction, transgenic mice, and matrix metalloproteinase were generated by burst analysis of keywords. The reference with the most citations was a contemporary review summarizing the role of cardiac fibroblasts and fibrogenic molecules in promoting fibrogenesis following myocardial injury. The top 3 most influential countries were the United States, China, and Germany, while the most cited institution was Shanghai Jiao Tong University, followed by Nanjing Medical University and Capital Medical University.

Conclusions

The number and impact of global publications on cardiac fibrosis has expanded rapidly over the past 30 years. These results are in favor of paving the way for future research on the pathogenesis, diagnosis, and treatment of cardiac fibrosis.

The role of endothelial cell in cardiac hypertrophy: Focusing on angiogenesis and intercellular crosstalk

Cardiac hypertrophy is characterized by cardiac structural remodeling, fibrosis, microvascular rarefaction, and chronic inflammation. The heart is structurally organized by different cell types, including cardiomyocytes, fibroblasts, endothelial cells, and immune cells. These cells highly interact with each other by a number of paracrine or autocrine factors. Cell-cell communication is indispensable for cardiac development, but also plays a vital role in regulating cardiac response to damage. Although cardiomyocytes and fibroblasts are deemed as key regulators of hypertrophic stimulation, other cells, including endothelial cells, also exert important effects on cardiac hypertrophy. More particularly, endothelial cells are the most abundant cells in the heart, which make up the basic structure of blood vessels and are widespread around other cells in the heart, implicating the great and inbuilt advantage of intercellular crosstalk. Cardiac microvascular plexuses are essential for transport of liquids, nutrients, molecules and cells within the heart. Meanwhile, endothelial cell-mediated paracrine signals have multiple positive or negative influences on cardiac hypertrophy. However, a comprehensive discussion of these influences and consequences is required. This review aims to summarize the basic function of endothelial cells in angiogenesis, with an emphasis on angiogenic molecules under hypertrophic conditions. The secondary objective of the research is to fully discuss the key molecules involved in the intercellular crosstalk and the endothelial cell-mediated protective or detrimental effects on other cardiac cells. This review provides a more comprehensive understanding of the overall role of endothelial cells in cardiac hypertrophy and guides the therapeutic approaches and drug development of cardiac hypertrophy.

Hydrogen sulfide alleviates mitochondrial damage and ferroptosis by regulating OPA3-NFS1 axis in doxorubicin-induced cardiotoxicity

Ferroptosis is a major cause of cardiotoxicity induced by doxorubicin (DOX). Previous studies have shown that hydrogen sulfide (H₂S) inhibits ferroptosis in cardiomyocytes and myoblasts, but the underlying mechanism has not been fully elucidated. In this study, we investigated the role of H₂S in protecting against DOX-induced cardiotoxicity both in vivo and in vitro, and elucidated the potential mechanisms involved. We found that DOX downregulated the expression of glutathione peroxidase 4 (GPX4) and NFS1, and upregulated the expression of acyl-coenzyme A synthetase long-chain family member 4 (ACSL4) expression level, resulting in increased lipid peroxidation and ferroptosis. Additionally, DOX inhibited MFN2 expression and increased DRP1 and FIS1 expression, leading to abnormal mitochondrial structure and function. In contrast, exogenous H₂S inhibited DOX-induced ferroptosis by restoring GPX4 and NFS1 expression, and reducing lipid peroxidation in H9C2 cells. This effect was similar to that of the ferroptosis antagonist ferrostatin-1 (Fer-1) in protecting against DOX-induced cardiotoxicity. We further demonstrated that the protective effect of H₂S was mediated by the key mitochondrial membrane protein optic atrophy 3 (OPA3), which was downregulated by DOX and restored by exogenous H₂S. Overexpression of OPA3 alleviated DOX-induced mitochondrial dysfunction and ferroptosis both in vivo and in vitro. Mechanistically, NFS1 has an inhibitory effect on ferroptosis, and NFS1 deficiency increases the susceptibility of cardiomyocytes to ferroptosis. OPA3 is involved in the regulation of ferroptosis by interacting with NFS1. Post-translationally, DOX promoted OPA3 ubiquitination, while exogenous H₂S antagonized OPA3 ubiquitination by promoting OPA3 s-sulfhydration. In summary, our findings suggested that H₂S protects against DOX-induced cardiotoxicity by inhibiting ferroptosis via targeting the OPA3-NFS1 axis. This provides a potential therapeutic strategy for the treatment of DOX-induced cardiotoxicity.

The roles of ETS transcription factors in liver fibrosis

E26 transformation specific or E twenty-six (ETS) protein family consists of 28 transcription factors, five of which, named ETS1/2, PU.1, ERG and EHF, are known to involve in the development of liver fibrosis, and are expected to become diagnostic markers or therapeutic targets of liver fibrosis. In recent years, some small molecule inhibitors of ETS protein family have been discovered, which might open up a new path for the liver fibrosis therapy targeting ETS. This article reviews the research progress of ETS family members in the development liver fibrosis as well as their prospect of clinical application.

TYMSOS-miR-101-3p-NETO2 axis promotes osteosarcoma progression

BACKGROUND

Osteosarcoma (OS) is a type of bone cancer most often affects pre-teens and teens, but it is still a rare disorder. Neuropilin and tolloid-like 2 (NETO2) has been reported to promote OS progression, but its upstream mechanism in OS cells remains obscure.

METHODS

Quantitative real-time PCR (RT-qPCR) and Western blot were conducted to examine RNA and protein levels, separately. Functional assays were performed to assess the impact of NETO2 on OS cell malignancy. Moreover, bioinformatics analyses and mechanism experiments were performed to identify the upstream mechanism of NETO2 in OS cells.

RESULTS

Functionally, NETO2 depletion repressed cell proliferation, migration and invasion as well as epithelial-mesenchymal transition (EMT) but triggered the apoptosis of OS cells. NETO2 is directly targeted and negatively regulated by microRNA-101-3p (miR-101-3p). Mechanically, miR-101-3p could combine with long noncoding RNA (lncRNA) TYMS opposite strand RNA (TYMSOS) in OS cells. In addition, our study proved that TYMSOS promotes the malignancy of OS via elevating NETO2 expression as miR-101-3p sponge.

CONCLUSION

TYMSOS-miR-101-3p-NETO2 axis promotes the malignant behaviors of OS cells, which might offer a novel sight for OS treatment.

Endothelial-cell-mediated mechanism of coronary microvascular dysfunction leading to heart failure with preserved ejection fraction

Although the prevalence of heart failure with preserved ejection fraction (HFpEF) is growing worldwide, its complex pathophysiology has yet to be fully elucidated, and multiple hypotheses have all failed to produce a viable target for therapeutic action or provide effective treatment. Cardiac remodeling has long been considered an important mechanism of HFpEF. Strong evidence has been reported over the past years that coronary microvascular dysfunction (CMD), manifesting as structural and functional abnormalities of coronary microvasculature, also contributes to the evolution of HFpEF. However, the mechanisms of CMD are still not well understood and need to be studied further. Coronary microvascular endothelial cells (CMECs) are one of the most abundant cell types in the heart by number and active players in cardiac physiology and pathology. CMECs are not only important cellular mediators of cardiac vascularization but also play an important role in disease pathophysiology by participating in the inception and progression of cardiac remodeling. CMECs are also actively involved in the pathogenesis of CMD. Numerous studies have confirmed that CMD is closely related to cardiac remodeling. ECs may serve a critical function in mediating the connection between CMD and HFpEF. It follows that CMECs participate in the mechanism of CMD leading to HFpEF. In this review article, we focus on the role of CMD in the pathogenesis of HFpEF resulting from cardiac remodeling and highlight the subsequent complexity of the EC-mediated correlation between CMD and HFpEF.

Growth Differentiation Factor 7 Prevents Sepsis-Induced Acute Lung Injury in Mice

Objective

Acute lung injury (ALI) is a life-threatening complication during sepsis and contributes to multiple organ failure and high mortality for septic patients. The present study aims to investigate the role and molecular basis of growth differentiation factor 7 (GDF7) in sepsis-induced ALI.

Methods

Mice were subcutaneously injected with recombinant mouse GDF7 Protein (rmGDF7) and then intratracheally injected with lipopolysaccharide (LPS) to generate sepsis-induced ALI. Primary peritoneal macrophages were isolated to further evaluate the role and underlying mechanism of GDF7 in vitro.

Results

GDF7 was downregulated in LPS-stimulated lung tissues, and rmGDF7 treatment significantly inhibited inflammation and oxidative stress in ALI mice, thereby preventing LPS-induced pulmonary injury and dysfunction. Mechanistically, we found that rmGDF7 activated AMP-activated protein kinase (AMPK), and AMPK inhibition significantly blocked the anti-inflammatory and antioxidant effects of rmGDF7 during LPS-induced ALI. Further findings revealed that rmGDF7 activated AMPK through a downregulated stimulator of interferon gene (STING) in vivo and in vitro.

Conclusion

GDF7 prevents LPS-induced inflammatory response, oxidative stress, and ALI by regulating the STING/AMPK pathway. Our findings for the first time identify GDF7 as a potential agent for the treatment of sepsis-induced ALI.

Resolving the gene expression maps of human first-trimester chorionic villi with spatial transcriptome

The placenta is important for fetal development in mammals, and spatial transcriptomic profiling of placenta helps to resolve its structure and function. In this study, we described the landscape of spatial transcriptome of human placental villi obtained from two pregnant women at the first trimester using the modified Stereo-seq method applied for paraformaldehyde (PFA) fixation samples. The PFA fixation of human placenta villi was better than fresh villi embedded in optimum cutting temperature (OCT) compound, since it greatly improved tissue morphology and the specificity of RNA signals. The main cell types in chorionic villi such as syncytiotrophoblasts (SCT), villous cytotrophoblasts (VCT), fibroblasts (FB), and extravillous trophoblasts (EVT) were identified with the spatial transcriptome data, whereas the minor cell types of Hofbauer cells (HB) and endothelial cells (Endo) were spatially located by deconvolution of scRNA-seq data. We demonstrated that the Stereo-seq data of human villi could be used for sophisticated analyses such as spatial cell-communication and regulatory activity. We found that the SCT and VCT exhibited the most ligand-receptor pairs that could increase differentiation of the SCT, and that the spatial localization of specific regulons in different cell types was associated with the pathways related to hormones transport and secretion, regulation of mitotic cell cycle, and nutrient transport pathway in SCT. In EVT, regulatory pathways such as the epithelial to mesenchyme transition, epithelial development and differentiation, and extracellular matrix organization were identified. Finally, viral receptors and drug transporters were identified in villi according to the pathway analysis, which could help to explain the vertical transmission of several infectious diseases and drug metabolism efficacy. Our study provides a valuable resource for further investigation of the placenta development, physiology and pathology in a spatial context.

Macrophage Sprouty4 deficiency diminishes sepsis-induced acute lung injury in mice

OBJECTIVE

Inflammation and oxidative stress play critical roles in sepsis-induced acute lung injury (ALI). Sprout4 (Spry4) is involved in regulating inflammation and tissue injury; however, its role and mechanism in sepsis-induced ALI remain elusive.

METHODS

Macrophage-specific Spry4 knockout (Spry4^MKO), transgenic (Spry4^MTG) mice and matched control littermates were generated and exposed to cecum ligation and puncture (CLP) surgery to establish bacterial sepsis-induced ALI. Bone marrow-derived macrophages (BMDMs) from Spry4^MKO or Spry4^MTG mice were isolated and subjected to lipopolysaccharide (LPS) stimulation to further validate the role of Spry4 in vitro. To verify the necessity of AMP-activated protein kinase (AMPK), Spry4 and AMPK double knockout mice and compound C were used in vivo and in vitro. BMDMs were treated with STO-609 to inhibit calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2).

RESULTS

We found that macrophage Spry4 was increased in CLP mice and positively correlated with sepsis-induced ALI. Macrophage Spry4 deficiency prevented, while macrophage Spry4 overexpression exacerbated sepsis-induced inflammation, oxidative stress and ALI in mice and BMDMs. Mechanistic studies revealed that macrophage Spry4 deficiency alleviated sepsis-induced ALI through activating CaMKK2/AMPK pathway.

CONCLUSION

Our study identify macrophage Spry4 as a promising predictive and therapeutic target of sepsis-induced ALI.

The emerging role of leptin in obesity-associated cardiac fibrosis: evidence and mechanism

Cardiac fibrosis is a hallmark of various cardiovascular diseases, which is quite commonly found in obesity, and may contribute to the increased incidence of heart failure arrhythmias, and sudden cardiac death in obese populations. As an endogenous regulator of adiposity metabolism, body mass, and energy balance, obesity, characterized by increased circulating levels of the adipocyte-derived hormone leptin, is a critical contributor to the pathogenesis of cardiac fibrosis. Although there are some gaps in our knowledge linking leptin and cardiac fibrosis, this review will focus on the interplay between leptin and major effectors involved in the pathogenesis underlying cardiac fibrosis at both cellular and molecular levels based on the current reports. The profibrotic effect of leptin is predominantly mediated by activated cardiac fibroblasts but may also involve cardiomyocytes, endothelial cells, and immune cells. Moreover, a series of molecular signals with a known profibrotic property is closely involved in leptin-induced fibrotic events. A more comprehensive understanding of the underlying mechanisms through which leptin contributes to the pathogenesis of cardiac fibrosis may open up a new avenue for the rapid emergence of a novel therapy for preventing or even reversing obesity-associated cardiac fibrosis.

Macrophage SAMSN1 protects against sepsis-induced acute lung injury in mice

OBJECTIVE

Inflammation and oxidative stress contribute to the progression of sepsis-induced acute lung injury (ALI). SAM domain, SH3 domain and nuclear localization signals 1 (SAMSN1) is a signaling adaptor protein, and mainly regulates inflammatory response of various immune cells. The present study generates macrophage-specific SAMSN1-knockout (Samsn1MKO) and SAMSN1-transgenic (Samsn1MTG) mice to investigate its role and mechanism in sepsis-induced ALI.

METHODS

Samsn1MKO and Samsn1MTG mice were exposed to lipopolysaccharide (LPS) instillation or cecal ligation and puncture (CLP) surgery to induce sepsis-induced ALI. Bone marrow transplantation, cellular depletion and non-invasive adoptive transfer of bone marrow-derived macrophages (BMDMs) were performed to validate the role of macrophage SAMSN1 in sepsis-induced ALI in vivo. Meanwhile, BMDMs were isolated from Samsn1MKO or Samsn1MTG mice to further clarify the role of SAMSN1 in vitro.

RESULTS

Macrophage SAMSN1 expression was increased in response to LPS stimulation, and negatively correlated with LPS-induced ALI in mice. Macrophage SAMSN1 deficiency exacerbated, while macrophage SAMSN1 overexpression ameliorated LPS-induced inflammation, oxidative stress and ALI in mice and in BMDMs. Mechanistically, we found that macrophage SAMSN1 overexpression prevented LPS-induced ALI though activating AMP-activated protein kinase α2 (AMPKα2) in vivo and in vitro. Further studies revealed that SAMSN1 directly bound to growth factor receptor bound protein 2-associated protein 1 (GAB1) to prevent its protein degradation, and subsequently enhanced protein kinase A (PKA)/AMPKα2 activation in a protein tyrosine phosphatase, non-receptor type 11 (PTPN11, also known as SHP2)-dependent manner. Moreover, we observed that macrophage SAMSN1 overexpression diminished CLP-induced ALI in mice.

CONCLUSION

Our study documents the protective role of macrophage SAMSN1 against sepsis-induced inflammation, oxidative stress and ALI through activating AMPKα2 in a GAB1/SHP2/PKA pathway, and defines it as a promising biomarker and therapeutic target to treat sepsis-induced ALI.

The Endothelial Transcription Factor ERG Mediates a Differential Role in the Aneurysmatic Ascending Aorta with Bicuspid or Tricuspid Aorta Valve: A Preliminary Study

The pathobiology of ascending aorta aneurysms (AAA) onset and progression is not well understood and only partially characterized. AAA are also complicated in case of bicuspid aorta valve (BAV) anatomy. There is emerging evidence about the crucial role of endothelium-related pathways, which show in AAA an altered expression and function. Here, we examined the involvement of ERG-related pathways in the differential progression of disease in aortic tissues from patients having a BAV or tricuspid aorta valve (TAV) with or without AAA. Our findings identified ERG as a novel endothelial-specific regulator of TGF-β-SMAD, Notch, and NO pathways, by modulating a differential fibrotic or calcified AAA progression in BAV and TAV aortas. We provided evidence that calcification is correlated to different ERG expression (as gene and protein), which appears to be under control of Notch signaling. The latter, when increased, associated with an early calcification in aortas with BAV valve and aneurysmatic, was demonstrated to favor the progression versus severe complications, i.e., dissection or rupture. In TAV aneurysmatic aortas, ERG appeared to modulate fibrosis. Therefore, we proposed that ERG may represent a sensitive tissue biomarker to monitor AAA progression and a target to develop therapeutic strategies and influence surgical procedures.

TRIM7 modulates NCOA4-mediated ferritinophagy and ferroptosis in glioblastoma cells

Objective

Glioblastoma is one of the most common intracranial malignant tumors with an unfavorable prognosis, and iron metabolism as well as ferroptosis are implicated in the pathogenesis of glioblastoma. The present study aims to decipher the role and mechanisms of tripartite motif-containing protein 7 (TRIM7) in ferroptosis and glioblastoma progression.

Methods

Stable TRIM7-deficient or overexpressing human glioblastoma cells were generated with lentiviral vectors, and cell survival, lipid peroxidation and iron metabolism were evaluated. Immunoprecipitation, protein degradation and ubiquitination assays were performed to demonstrate the regulation of TRIM7 on its candidate proteins.

Results

TRIM7 expression was elevated in human glioblastoma cells and tissues. TRIM7 silence suppressed growth and induced death, while TRIM7 overexpression facilitated growth and inhibited death of human glioblastoma cells. Meanwhile, TRIM7-silenced cells exhibited increased iron accumulation, lipid peroxidation and ferroptosis, which were significantly reduced by TRIM7 overexpression. Mechanistically, TRIM7 directly bound to and ubiquitinated nuclear receptor coactivator 4 (NCOA4) using K48-linked chains, thereby reducing NCOA4-mediated ferritinophagy and ferroptosis of human glioblastoma cells. Moreover, we found that TRIM7 deletion sensitized human glioblastoma cells to temozolomide therapy.

Conclusion

We for the first time demonstrate that TRIM7 modulates NCOA4-mediated ferritinophagy and ferroptosis in glioblastoma cells, and our findings provide a novel insight into the progression and treatment for human glioblastoma.

MicroRNA-147a Targets SLC40A1 to Induce Ferroptosis in Human Glioblastoma

Objective. Glioblastoma is one of the most common malignant tumors in the brain, and these glioblastoma patients have very poor prognosis. Ferroptosis is involved in the progression of various tumors, including the glioblastoma. This study aims to determine the involvement of microRNA (miR)-147a in regulating ferroptosis of glioblastoma in vitro. Methods. Human glioblastoma cell lines were transfected with the inhibitor, mimic and matched negative controls of miR-147a in the presence or absence of ferroptotic inducers. To knock down the endogenous solute carrier family 40 member 1 (SLC40A1), cells were transfected with the small interfering RNA against SLC40A1. In addition, cells with or without the miR-147a mimic treatment were also incubated with temozolomide (TMZ) to investigate whether miR-147a overexpression could sensitize human glioblastoma cells to TMZ chemotherapy in vitro. Results. We found that miR-147a level was decreased in human glioblastoma tissues and cell lines and that the miR-147a mimic significantly suppressed the growth of glioblastoma cells in vitro. In addition, miR-147a expression was elevated in human glioblastoma cells upon erastin or RSL3 stimulation. Treatment with the miR-147a mimic significantly induced ferroptosis of glioblastoma cells, and the ferroptotic inhibitors could block the miR-147a mimic-mediated tumor suppression in vitro. Conversely, the miR-147a inhibitor prevented erastin- or RSL3-induced ferroptosis and increased the viability of glioblastoma cells in vitro. Mechanistically, we determined that miR-147a directly bound to the 3 $\prime$ -untranslated region of SLC40A1 and inhibited SLC40A1-mediated iron export, thereby facilitating iron overload, lipid peroxidation, and ferroptosis. Furthermore, miR-147a mimic-treated human glioblastoma cells exhibited higher sensitivity to TMZ chemotherapy than those treated with the mimic control in vitro. Conclusion. We for the first time determine that miR-147a targets SLC40A1 to induce ferroptosis in human glioblastoma in vitro.

Dysfunctional ERG signaling drives pulmonary vascular aging and persistent fibrosis

Vascular dysfunction is a hallmark of chronic diseases in elderly. The contribution of the vasculature to lung repair and fibrosis is not fully understood. Here, we performed an epigenetic and transcriptional analysis of lung endothelial cells (ECs) from young and aged mice during the resolution or progression of bleomycin-induced lung fibrosis. We identified the transcription factor ETS-related gene (ERG) as putative orchestrator of lung capillary homeostasis and repair, and whose function is dysregulated in aging. ERG dysregulation is associated with reduced chromatin accessibility and maladaptive transcriptional responses to injury. Loss of endothelial ERG enhances paracrine fibroblast activation in vitro, and impairs lung fibrosis resolution in young mice in vivo. scRNA-seq of ERG deficient mouse lungs reveales transcriptional and fibrogenic abnormalities resembling those associated with aging and human lung fibrosis, including reduced number of general capillary (gCap) ECs. Our findings demonstrate that lung endothelial chromatin remodeling deteriorates with aging leading to abnormal transcription, vascular dysrepair, and persistent fibrosis following injury.

The NLRP3 Inflammasome as a Novel Therapeutic Target for Cardiac Fibrosis

Cardiac fibrosis often has adverse cardiovascular effects, including heart failure, sudden death, and malignant arrhythmias. However, there is no targeted therapy for cardiac fibrosis. Inflammation is known to play a crucial role in the disorder, and the NLR pyrin domain-containing-3 (NLRP3) inflammasome is closely associated with innate immunity. Therefore, further understanding the pathophysiological role of the inflammasome in cardiac fibrosis may provide novel strategies for the prevention and treatment of the disorder. The aim of this review was to summarize the present knowledge of NLRP3 inflammasome-related mechanisms underlying cardiac fibrosis and to suggest potential targeted therapy that could be used to treat the condition.

Diagnostic and Therapeutic Properties of Exosomes in Cardiac Fibrosis

Cardiac fibrosis results from both the differentiation of cardiac fibroblasts and excessive accumulation of extracellular matrix (ECM), leading to myocardial stiffness and reduced compliance of the ventricular wall. The conversion of cardiac fibroblasts to myofibroblasts is the most important initiating step in the process of this pathological cardiac remodeling. It occurs during the progression of many cardiovascular diseases, adversely influencing both the clinical course and outcome of the disease. The pathogenesis is complex and there is no effective treatment. Exosomes are extracellular vesicles that mediate intercellular communication through delivering specific cargoes of functional nucleic acids and proteins derived from particular cell types. Recent studies have found that exosomes play an important role in the diagnosis and treatment of cardiac fibrosis, and is a potential biotherapeutics and drug delivery vectors for the treatment of cardiac fibrosis. The present review aimed to summarize the current knowledge of exosome-related mechanisms underlying cardiac fibrosis and to suggest potential therapy that could be used to treat the condition.

MicroRNA-1224-5p Aggravates Sepsis-Related Acute Lung Injury in Mice

Oxidative stress and inflammation are implicated in the development of sepsis-related acute lung injury (ALI). MicroRNA-1224-5p (miR-1224-5p) plays critical roles in regulating inflammatory response and reactive oxygen species (ROS) production. The present study is aimed at investigating the role and underlying mechanisms of miR-1224-5p in sepsis-related ALI. Mice were intratracheally injected with lipopolysaccharide (LPS, 5 mg/kg) for 12 h to induce sepsis-related ALI. To manipulate miR-1224-5p level, mice were intravenously injected with the agomir, antagomir, or matched controls for 3 consecutive days. Murine peritoneal macrophages were stimulated with LPS (100 ng/mL) for 6 h to further validate the role of miR-1224-5p in vitro. To inhibit adenosine 5′-monophosphate-activated protein kinase alpha (AMPKα) or peroxisome proliferator activated receptor-gamma (PPAR-γ), compound C or GW9662 was used in vivo and in vitro. We found that miR-1224-5p levels in lungs were elevated by LPS injection, and that the miR-1224-5p antagomir significantly alleviated LPS-induced inflammation, oxidative stress, and ALI in mice. Conversely, the miR-1224-5p agomir aggravated inflammatory response, ROS generation, and pulmonary dysfunction in LPS-treated mice. In addition, the miR-1224-5p antagomir reduced, while the miR-1224-5p agomir aggravated LPS-induced inflammation and oxidative stress in murine peritoneal macrophages. Further findings revealed that miR-1224-5p is directly bound to the 3′-untranslated regions of PPAR-γ and subsequently suppressed PPAR-γ/AMPKα axis, thereby aggravating LPS-induced ALI in vivo and in vitro. We demonstrate for the first time that endogenous miR-1224-5p is a critical pathogenic factor for inflammation and oxidative damage during LPS-induced ALI through inactivating PPAR-γ/AMPKα axis. Targeting miR-1224-5p may help to develop novel approaches to treat sepsis-related ALI.

MicroRNA-299a-5p Protects against Spinal Cord Injury through Activating AMPK Pathway

Objective

Inflammation and oxidative stress are implicated in the pathogenesis of spinal cord injury (SCI). The present study is aimed at investigating the function and molecular basis of microRNA-299a-5p (miR-299a-5p) during SCI in mice.

Methods

Mice were exposed to SCI surgery and then intrathecally injected with the agomir, antagomir, or matched negative controls of miR-299a-5p to overexpress or silence miR-299a-5p. To inhibit AMP-activated protein kinase (AMPK), mice were intraperitoneally injected with compound C (CC). To overexpress pH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1), lentiviral vectors were used.

Results

The miR-299a-5p expression in the spinal cord was dramatically reduced by SCI stimulation. The miR-299a-5p agomir prevents, while the miR-299a-5p antagomir exacerbates inflammation, oxidative stress, and SCI in mice. Mechanistically, we found that miR-299a-5p directly inhibited PHLPP1 and subsequently activated AMPK pathway. The PHLPP1 overexpression of AMPK inhibition with either genetic or pharmacologic methods dramatically abolished the miR-299a-5p agomir-mediated protective effects against SCI.

Conclusion

miR-299a-5p protects against spinal cord injury through activating AMPK pathway.

HDAC11 promotes both NLRP3/caspase-1/GSDMD and caspase-3/GSDME pathways causing pyroptosis via ERG in vascular endothelial cells

Histone deacetylase 11 (HDAC11), a sole member of the class IV HDAC subfamily, participates in various cardiovascular diseases. Recent evidence showed that pyroptosis was a form of inflammatory programmed cell death and is critical for atherosclerosis (AS). However, little is known about the effect of HDAC11 on endothelial cell pyroptosis in AS. Thus, this study aims to investigate the role of HDAC11 in vascular endothelial cell pyroptosis and its molecular mechanism. Firstly, we found that HDAC11 expression was up-regulated and pyroptosis occurred in the aorta of ApoE^−/− mice fed with a high-fat diet (HFD) for 8 or 12 weeks. Then, in vitro study found the treatment of human umbilical vein endothelial cells (HUVECs) with tumor necrosis factor-α (TNF-α) resulted in pyroptosis, as evidenced by activation of caspase-1 and caspase-3 activation, cleavage of downstream gasdermin D (GSDMD) and gasdermin E (GSDME/DFNA5), the release of pro-inflammatory cytokines interleukin (IL)-1β, IL-6 and IL-18, as well as elevation of LDH activity and increase of propidium iodide (PI)-positive cells. Besides, TNF-α increased HDAC11 expression and induced pyroptosis via TNFR1 in HUVECs. HDAC11 knockdown mitigated pyroptosis by suppressing both NLRP3/caspase-1/GSDMD and caspase-3/GSDME pathways in TNF-α-induced HUVECs. Moreover, GSDME knockdown by siRNA significantly decreased pyroptosis and inflammatory response, while treatment with disulfiram or necrosulfonamide (NSA) further augmented the inhibitory effects of GSDME siRNA on pyroptosis and inflammatory response. Further studies found HDAC11 formed a complex with ERG and decreased the acetylation levels of ERG. More importantly, ERG knockdown augmented vascular endothelial cell pyroptosis in TNF-α-induced HUVECs. Taken together, our study suggests that HDAC11 might promote both NLRP3/caspase-1/GSDMD and caspase-3/GSDME pathways leading to pyroptosis via regulation of ERG acetylation in HUVECs. Modulation of HDAC11 may serve as a potential target for therapeutic strategies of AS.

MicroRNA-181a-5p Promotes Osteosarcoma Progression via PTEN/AKT Pathway

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents with poor prognosis. MicroRNA-181a-5p (miR-181a-5p) is involved in the progression of various tumors; however, its role and underlying mechanism in osteosarcoma remains unclear. In this study, we found that miR-181a-5p was upregulated in human osteosarcoma cells and tissues. miR-181a-5p mimic significantly promoted, while miR-181a-5p inhibitor blocked the proliferation, colony formation, migration, invasion, and cell cycle progression of osteosarcoma cells. Mechanistically, miR-181a-5p bound to the 3′-untranslational region of phosphatase and tensin homolog (PTEN) and reduced its protein expression, thereby activating protein kinase B (PKB/AKT) pathway. Either PTEN overexpression or AKT inhibition notably blocked the tumor-promoting effects of miR-181a-5p. Moreover, we observed that miR-181a-5p mimic further inhibited growth of human osteosarcoma cells in the presence of adriamycin or cisplatin. Overall, miR-181a-5p promotes osteosarcoma progression via PTEN/AKT pathway and it is a promising therapeutic target to treat osteosarcoma.

Fibronectin type III domain-containing 5 improves aging-related cardiac dysfunction in mice

Aging is an important risk factor for cardiovascular diseases, and aging‐related cardiac dysfunction serves as a major determinant of morbidity and mortality in elderly populations. Our previous study has identified fibronectin type III domain‐containing 5 (FNDC5) and its cleaved form, irisin, as the cardioprotectant against doxorubicin‐induced cardiomyopathy. Herein, aging or matched young mice were overexpressed with FNDC5 by adeno‐associated virus serotype 9 (AAV9) vectors, or subcutaneously infused with irisin to uncover the role of FNDC5 in aging‐related cardiac dysfunction. To verify the involvement of nucleotide‐binding oligomerization domain‐like receptor with a pyrin domain 3 (NLRP3) and AMP‐activated protein kinase α (AMPKα), Nlrp3 or Ampkα2 global knockout mice were used. Besides, young mice were injected with AAV9‐FNDC5 and maintained for 12 months to determine the preventive effect of FNDC5. Moreover, neonatal rat cardiomyocytes were stimulated with tumor necrosis factor‐α (TNF‐α) to examine the role of FNDC5 in vitro. We found that FNDC5 was downregulated in aging hearts. Cardiac‐specific overexpression of FNDC5 or irisin infusion significantly suppressed NLRP3 inflammasome and cardiac inflammation, thereby attenuating aging‐related cardiac remodeling and dysfunction. In addition, irisin treatment also inhibited cellular senescence in TNF‐α‐stimulated cardiomyocytes in vitro. Mechanistically, FNDC5 activated AMPKα through blocking the lysosomal degradation of glucagon‐like peptide‐1 receptor. More importantly, FNDC5 gene transfer in early life could delay the onset of cardiac dysfunction during aging process. We prove that FNDC5 improves aging‐related cardiac dysfunction by activating AMPKα, and it might be a promising therapeutic target to support cardiovascular health in elderly populations.

MicroRNA‐495‐3p diminishes doxorubicin‐induced cardiotoxicity through activating AKT

Doxorubicin (Dox) is a broad‐spectrum antitumour agent; however, its clinical application is impeded due to the cumulative cardiotoxicity. The present study aims to investigate the role and underlying mechanisms of microRNA‐495‐3p (miR‐495‐3p) in Dox‐induced cardiotoxicity. Herein, we found that cardiac miR‐495‐3p expression was significantly decreased in Dox‐treated hearts, and that the miR‐495‐3p agomir could prevent oxidative stress, cell apoptosis, cardiac mass loss, fibrosis and cardiac dysfunction upon Dox stimulation. In contrast, the miR‐495‐3p antagomir dramatically aggravated Dox‐induced cardiotoxicity in mice. Besides, we found that the miR‐495‐3p agomir attenuated, while the miR‐495‐3p antagomir exacerbated Dox‐induced oxidative stress and cellular injury in vitro. Mechanistically, we demonstrated that miR‐495‐3p directly bound to the 3′‐untranslational region of phosphate and tension homology deleted on chromosome ten (PTEN), downregulated PTEN expression and subsequently activated protein kinase B (PKB/AKT) pathway, and that PTEN overexpression or AKT inhibition completely abolished the cardioprotective effects of the miR‐495‐3p agomir. Our study for the first time identify miR‐495‐3p as an endogenous protectant against Dox‐induced cardiotoxicity through activating AKT pathway in vivo and in vitro.

MicroRNA-665-3p exacerbates nonalcoholic fatty liver disease in mice

Oxidative stress and chronic inflammation are major culprits of nonalcoholic fatty liver disease (NAFLD). MicroRNA-665-3p (miR-665-3p) is implicated in regulating inflammation and oxidative stress; however, its role and molecular basis in NAFLD remain elusive. Herein, we measured a significant upregulation of miR-665-3p level in the liver and primary hepatocytes upon high fat diet (HFD) or 0.5 mmol/L palmitic acid plus 1.0 mmol/L oleic acid stimulation, and the elevated miR-665-3p expression aggravated oxidative stress, inflammation and NAFLD progression in mice. In contrast, miR-665-3p inhibition by the miR-665-3p antagomir significantly prevented HFD-induced oxidative stress, inflammation and hepatic dysfunction in vivo. Manipulation of miR-665-3p in primary hepatocytes also caused similar phenotypic alterations in vitro. Mechanistically, we demonstrated that miR-665-3p directly bound to the 3'-untranslated region of fibronectin type III domain-containing 5 (FNDC5) to downregulate its expression and inactivated the downstream AMP-activated protein kinase alpha (AMPKα) pathway, thereby facilitating oxidative stress, inflammation and NAFLD progression. Our findings identify miR-665-3p as an endogenous positive regulator of NAFLD via inactivating FNDC5/AMPKα pathway, and inhibiting miR-665-3p may provide novel therapeutic strategies to treat NAFLD.

Pitavastatin maintains MAPK7 expression and alleviates angiotensin II-induced vascular endothelial cell inflammation and injury

Statins have been reported to suppress vascular remodeling in rats with spontaneous hypertension. However, the possible effects of the statin pitavastatin on hypertension-induced endothelial inflammation and injury remain to be fully elucidated. The present study aimed to evaluate the effects of pitavastatin on HUVEC injury and inflammation. HUVECs were exposed to angiotensin (Ang) II with or without pitavastatin co-treatment, after which MAPK7 expression was detected via reverse transcription-quantitative PCR and western blotting. MAPK7 expression was additionally silenced in HUVECs via transfection with short hairpin RNA, followed by Ang II treatment with or without pitavastatin. Cell viability, inflammation, reactive oxygen species (ROS) production, nitric oxide (NO) production and cell apoptosis were then measured by using Cell Conting Kit-8, ELISA, commercial corresponding kits and TUNEL staining, respectively. Western blotting was also used to determine the protein expression of endothelial NO synthase and endothelin 1, and the proteins involved in apoptosis. Results of the present study demonstrated that the expression levels of MAPK7 in Ang II-induced endothelial cells were decreased, which was reversed following treatment with pitavastatin. Pitavastatin reversed the Ang II-induced reduction in cell viability and reversed the Ang II-induced increase in inflammatory factor and ROS levels and apoptosis in HUVECs by activating MAPK7. Treatment with pitavastatin also increased the production of NO in addition to increasing the expression of endothelial NO synthase and endothelin-1 in Ang II-induced HUVECs through MAPK7 activation. Collectively, results from the present study demonstrated that treatment with pitavastatin preserves MAPK7 expression to alleviate Ang II-induced vascular endothelial cell inflammation and injury. Therefore, findings of the present study may help to elucidate the mechanisms underlying the effects of pitavastatin on vascular endothelial cell inflammation and injury.

MicroRNA-1287-5p promotes ferroptosis of osteosarcoma cells through inhibiting GPX4

Osteosarcoma is the most prevalent primary bone malignancy in adolescents, and ferroptosis is implicated in its pathogenesis. MicroRNA (miR)-1287-5p plays critical roles in multiple human cancers, and the present study aims to investigate the role and underlying mechanisms of miR-1287-5p in regulating ferroptosis and osteosarcoma progression. Human osteosarcoma cell lines were treated with the mimic, inhibitor or matched controls of miR-1287-5p. Cell viability, colony formation, cell death ratio and ferroptosis were determined. miR-1287-5p expression was downregulated in human osteosarcoma, but upregulated upon ferroptotic stimulation. Overexpression of miR-1287-5p significantly induced, while inhibition of miR-1287-5p suppressed ferroptosis of osteosarcoma cells, thereby modulating cell viability and colony formation. Mechanistic studies indicated that miR-1287-5p directly bound to the 3'-untranslated region of glutathione peroxidase 4 (GPX4) to inhibit its protein level and activity, and that GPX4 overexpression completely abolished the miR-1287-5p mimic-mediated ferroptotic induction and tumor suppression. Moreover, the miR-1287-5p mimic dramatically sensitized human osteosarcoma cells to cisplatin chemotherapy. Our findings prove that miR-1287-5p promotes ferroptosis of osteosarcoma cells through inhibiting GPX4, identifying an adjuvant and even alternative method for the treatment of human osteosarcoma.

MicroRNA-137-3p Improves Nonalcoholic Fatty Liver Disease through Activating AMPKα

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide and can develop to nonalcoholic steatohepatitis and later hepatic cirrhosis with a high prevalence to hepatocellular carcinoma. Oxidative stress and chronic hepatic inflammation are implicated in the pathogenesis of NAFLD. MicroRNA-137-3p (miR-137-3p) are associated with oxidative stress and inflammation; however, its role and mechanism in NAFLD remain unclear. Mice were fed with a high-fat diet (HFD) for 24 weeks to establish the NAFLD model. To overexpress or suppress hepatic miR-137-3p expression, mice were intraperitoneally injected with the agomir, antagomir, or respective controls of miR-137-3p at a dose of 100 mg/kg weekly for 6 consecutive weeks before the mice were sacrificed. To validate the involvement of AMP-activated protein kinase alpha (AMPKα) or cAMP-specific phosphodiesterase 4D (PDE4D), HFD mice were intraperitoneally injected with 20 mg/kg compound C or 0.5 mg/kg rolipram every other day for 8 consecutive weeks before the mice were sacrificed. Hepatic miR-137-3p expression was significantly decreased in mice upon HFD stimulation. miR-137-3p agomir alleviated, while miR-137-3p antagomir facilitated HFD-induced oxidative stress, inflammation, and hepatic dysfunction in mice. Mechanistically, we revealed that miR-137-3p is directly bound to the 3'-untranslated region of PDE4D and subsequently increased hepatic cAMP level and protein kinase A activity, thereby activating the downstream AMPKα pathway. In summary, miR-137-3p improves NAFLD through activating AMPKα and it is a promising therapeutic candidate to treat NAFLD.

Ubiquitin-Specific Protease 29 Exacerbates Cerebral Ischemia-Reperfusion Injury in Mice

Oxidative stress and apoptosis contribute to the progression of cerebral ischemia/reperfusion (I/R) injury. Ubiquitin-specific protease 29 (USP29) is abundantly expressed in the brain and plays critical roles in regulating oxidative stress and cell apoptosis. The purpose of the present study is to investigate the role and underlying mechanisms of USP29 in cerebral I/R injury. Neuron-specific USP29 knockout mice were generated and subjected to cerebral I/R surgery. For USP29 overexpression, mice were stereotactically injected with the adenoassociated virus serotype 9 vectors carrying USP29 for 4 weeks before cerebral I/R. And primary cortical neurons were isolated and exposed to oxygen glucose deprivation/reperfusion (OGD/R) stimulation to imitate cerebral I/R injury in vitro. USP29 expression was elevated in the brain and primary cortical neurons upon I/R injury. Neuron-specific USP29 knockout significantly diminished, whereas USP29 overexpression aggravated cerebral I/R-induced oxidative stress, apoptosis, and neurological dysfunction in mice. In addition, OGD/R-induced oxidative stress and neuronal apoptosis were also attenuated by USP29 silence but exacerbated by USP29 overexpression in vitro. Mechanistically, neuronal USP29 enhanced p53/miR-34a-mediated silent information regulator 1 downregulation and then promoted the acetylation and suppression of brain and muscle ARNT-like protein, thereby aggravating oxidative stress and apoptosis upon cerebral I/R injury. Our findings for the first time identify that USP29 upregulation during cerebral I/R may contribute to oxidative stress, neuronal apoptosis, and the progression of cerebral I/R injury and that inhibition of USP29 may help to develop novel therapeutic strategies to treat cerebral I/R injury.