GSK-3β inhibition protects the rat heart from the lipopolysaccharide-induced inflammation injury via suppressing FOXO3A activity

STAT3/FoxO3a/Sirt1 pathway inhibition by ginsenoside Rc ameliorates cardiomyocyte damage in septic cardiomyopathy by altering macrophage polarization

This study explored the role and mechanism of action of ginsenoside Rc in treating septic cardiomyopathy. Ginsenoside Rc mitigated LPS-induced oxidative stress, inflammation, apoptosis, and mitochondrial dysfunction in cardiomyocytes and inhibited M1 polarization in macrophages. Ginsenoside Rc reduced the stimulating effect of M1-polarized macrophages on LPS-induced cardiomyocyte injury. Network pharmacological analysis suggested that ginsenoside Rc may play a role in septic cardiomyopathy through modulation of the STAT3/FoxO3a/Sirt1 pathway, which was validated in in vitro experiments. Ginsenoside Rc suppressed the expression of STAT3/FoxO3a pathway proteins and upregulated Sirt1. Moreover, influences of ginsenoside Rc on LPS-induced cardiomyocyte injury and macrophage polarization were abolished by ML115, a STAT3 agonist. In vivo, ginsenoside Rc notably improved myocardial injury and attenuated macrophage activation and inflammation in septic mice. Collectively, Ginsenoside Rc can ameliorate septic cardiomyopathy by modulating the STAT3/FoxO3a/Sirt1 pathway and altering macrophage polarization.

The dual missions of FoxO3a in inflammatory diseases: Regulation of antioxidant enzymes and involvement in programmed cell death

The transcription factor FoxO3a plays a crucial role in the process of cells adapting to various stress conditions. Multiple post - translational modifications and epigenetic mechanisms work together to precisely regulate the activity of FoxO3a, influencing its subcellular localization, stability, interactions with other proteins, DNA - binding affinity, and transcriptional regulatory capacity. Under different chemical signal stimuli and subcellular environments, the activation of FoxO3a triggered by oxidative stress can initiate diverse transcriptional programs, which are essential for the body to resist oxidative damage. In the development and progression of inflammatory diseases, FoxO3a exerts an important function by regulating the expression levels of antioxidant enzymes and participating in key physiological processes such as programmed cell death. This article comprehensively reviews the structural characteristics, mechanism of action of FoxO3a, as well as its functions in regulating antioxidant enzymes and programmed cell death. The aim is to deeply explore the potential of FoxO3a as a potential therapeutic target for preventing and treating damages such as inflammatory diseases caused by cellular stress.

Inflammation-related miRNAs in obesity, CVD, and NAFLD

Obesity, cardiovascular diseases (CVD), and nonalcoholic fatty liver disease (NAFLD) pose significant worldwide health challenges, characterized by complex interplay among inflammatory pathways that underlie their development. In this review, we examine the contribution of inflammation and associated signaling molecules to the pathogenesis of these conditions, while also emphasizing the significant participation of non-coding RNAs (ncRNAs) in modulating inflammatory pathways. In the context of obesity, aberrant expression patterns of inflammatory-associated miRNAs play a contributory role in adipose tissue inflammation and insulin resistance, thereby exacerbating disturbances in metabolic homeostasis. Similarly, in CVD, dysregulated miRNA expression alters inflammatory reactions, disrupts endothelial function, and induces cardiac remodeling, thereby impacting the advancement of the disease. Moreover, in the context of NAFLD, inflammatory-associated miRNAs are implicated in mediating hepatic inflammation, lipid deposition, and fibrosis, underscoring their candidacy as promising therapeutic targets. Additionally, the competing endogenous RNA (ceRNA) network has emerged as a novel regulatory mechanism in the etiology of CVD, obesity, and NAFLD, wherein ncRNAs assume pivotal roles in facilitating communication across diverse molecular pathways. Moreover, in the concluding section, we underscored the potential efficacy of directing interventions towards inflammatory-related miRNAs utilizing herbal remedies and therapies based on exosome delivery systems as a promising strategy for ameliorating pathologies associated with inflammation in obesity, CVD, and NAFLD.

Apigenin alleviates doxorubicin-induced myocardial pyroptosis by inhibiting glycogen synthase kinase-3β in vitro and in vivo

Apigenin, a natural flavonoid compound found in chamomile (Matricaia chamomilla L.) from the Asteraceae family, has been shown in our previous study to possess antimyocardial hypertrophy and anti-cardiac fibrosis effects. However, its effects and mechanisms on the pyroptosis of cardiomyocytes induced by doxorubicin (DOX) are poorly understood. The objective of this study was to investigate the role of GSK-3β and the effects of apigenin in DOX-induced cardiotoxicity. H9c2 cells stimulated with DOX were treated with SB216763 and apigenin. Additionally, a mouse model of DOX-induced cardiotoxicity was prepared and further treated with apigenin and SB216763 for 30 days. The findings revealed that treatment with SB216763 or apigenin resulted in a significant reduction in the levels of pyroptosis-related factors. Furthermore, the phosphorylation of GSK-3β was enhanced while the phosphorylation of nuclear factor-kB (NF-κB) p65 was reduced following treatment with either SB216763 or apigenin. Conversely, the effects of apigenin treatment were nullified in siRNA-GSK-3β-transfected cells. Results from computer simulation and molecular docking analysis supported that apigenin could directly target the regulation of GSK-3β. Therefore, our study confirmed that the inhibition of GSK-3β and treatment with apigenin effectively suppressed the pyroptosis of cardiomyocytes in both DOX-stimulated H9c2 cells and mice. These benefits may be attributed in part to the decrease in GSK-3β expression and subsequent reduction in NF-κB p65 activation. Overall, our findings revealed that the pharmacological targeting of GSK-3β may offer a promising therapeutic approach for alleviating DOX-induced cardiotoxicity.

PRMT6-FOXO3A ATTENUATES APOPTOSIS BY UPREGULATING PARKIN EXPRESSION IN INTESTINAL ISCHEMIA-REPERFUSION INJURY

ABSTRACT

Intestinal ischemia-reperfusion injury (IIRI) is a serious disease with high morbidity and mortality. This study aims to investigate the potential regulatory mechanisms involving protein arginine methyltransferase 6 (PRMT6), Forkhead box O3a (FoxO3a), and Parkin in IIRI and elucidate their roles in mediating cell apoptosis. The IIRI animal model was established and confirmed using hematoxylin and eosin staining. Oxygen-glucose deprivation and reperfusion (OGD/R) cell model was established to mimic ischemic injury in vitro . Transient transfection was used to overexpress or knock down genes. Cell death or apoptosis was assessed by propidium iodide staining, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, and flow cytometry. The expression of proteins was detected by western blot. The histopathology observed by hematoxylin and eosin staining suggested that the IIRI animal model was successfully established. Our findings revealed that IIRI resulted in increased Bax and decreased Bcl-2 levels. In vitro experiments showed that overexpression of Parkin decreased OGD/R injury and suppressed elevation of Bax/Bcl-2. PRMT6 regulated the methylation level of FoxO3a. Moreover, FoxO3a directly binds to Parkin, and FoxO3a overexpression reduced OGD/R-induced cell death and regulation of Parkin. Overexpression of PRMT6 can attenuate the downregulation of Parkin and elevation of Bax/Bcl-2 caused by OGD/R. Knockdown of PRMT6 promoted apoptosis in intestinal epithelial cells of OGD/R group, while PRMT6 overexpression exhibited the opposite effect. Notably, the levels of PRMT6, FoxO3a, and Parkin were decreased in IIRI mouse intestinal tissue. Knocking out PRMT6 causes a significant decrease in the lifespan of mice. Altogether, our results demonstrated that PRMT6 upregulated the expression of Parkin by regulating FoxO3a methylation level, attenuating the apoptosis induced by IIRI.

Pretreatment with interleukin-15 attenuates inflammation and apoptosis by inhibiting NF-κB signaling in sepsis-induced myocardial dysfunction

Sepsis-induced myocardial dysfunction (SIMD) is associated with poor prognosis and increased mortality in patients with sepsis. Cytokines are important regulators of both the initiation and progression of sepsis. Interleukin-15 (IL-15), a pro-inflammatory cytokine, has been linked to protective effects against myocardial infarction and myocarditis. However, the role of IL-15 in SIMD remains unclear. We established a mouse model of SIMD via cecal ligation puncture (CLP) surgery and a cell model of myocardial injury via lipopolysaccharide (LPS) stimulation. IL-15 expression was prominently upregulated in septic hearts as well as cardiomyocytes challenged with LPS. IL-15 pretreatment attenuated cardiac inflammation and cell apoptosis and improved cardiac function in the CLP model. Similar cardioprotective effects of IL-15 pretreatment were observed in vitro. As expected, IL-15 knockdown had the opposite effect on LPS-stimulated cardiomyocytes. Mechanistically, we found that IL-15 pretreatment reduced the expression of the pro-apoptotic proteins cleaved caspase-3 and Bax and upregulated the anti-apoptotic protein Bcl-2. RNA sequencing and Western blotting further confirmed that IL-15 pretreatment suppressed the activation of nuclear factor kappa B (NF-κB) signaling in mice with sepsis. Besides, the addition of NF-κB inhibitor can significantly attenuate cardiomyocyte apoptosis compared to the control findings. Our results suggest that IL-15 pretreatment attenuated the cardiac inflammatory responses and reduced cardiomyocyte apoptosis by partially inhibiting NF-κB signaling in vivo and in vitro, thereby improving cardiac function in mice with sepsis. These findings highlight a promising therapeutic strategy for SIMD.

miR-29b-1-5p exacerbates myocardial injury induced by sepsis in a mouse model by targeting TERF2

Myocardial damage is a critical complication and a significant contributor to mortality in sepsis. MicroRNAs (miRNAs) have emerged as key players in sepsis pathogenesis. In this study, we explore the effect and mechanisms of miR-29b-1-5p on sepsis-induced myocardial damage. Sepsis-associated Gene Expression Omnibus datasets (GSE72380 and GSE29914) are examined for differential miRNAs. The mouse sepsis-induced cardiac injury was established by Lipopolysaccharide (LPS) or cecal ligation and puncture (CLP). LPS-treated HL-1 mouse cardiomyocytes simulate myocardial injury in vitro. miR-29b-1-5p is co-upregulated in both datasets and in cardiac tissue from sepsis mouse and HL-1 cell models. miR-29b-1-5p expression downregulation was achieved by antagomir transduction and confirmed by real-time quantitative reverse transcription PCR. Survival analysis and echocardiography examination show that miR-29b-1-5p inhibition improves mice survival cardiac function in LPS- and CLP-induced sepsis mice. Hematoxylin and eosin and Masson's trichrome staining and Immunohistochemistry analysis of mouse myocardial α-smooth muscle actin show that miR-29b-1-5p inhibition reduces myocardial tissue injury and fibrosis. The inflammatory cytokines and cardiac troponin I (cTnI) levels in mouse serum and HL-1 cells are also decreased by miR-29b-1-5p inhibition, as revealed by enzyme-linked immunosorbent assay. The expressions of autophagy-lysosomal pathway-related and apoptosis-related proteins in the mouse cardiac tissues and HL-1 cells are evaluated by western blot analysis. The sepsis-induced activation of the autophagy-lysosomal pathway and apoptosis are also reversed by miR-29b-1-5p antagomir. MTT and flow cytometry measurement further confirm the protective role of miR-29b-1-5p antagomir in HL-1 cells by increasing cell viability and suppressing cell apoptosis. Metascape functionally enriches TargetScan-predicted miR-29b-1-5p target genes. TargetScan prediction and dual luciferase assay validate the targeting relationship between miR-29b-1-5p and telomeric repeat-binding factor 2 (TERF2). The expression and function of TERF2 in HL-1 cells and mice are also evaluated. MiR-29b-1-5p negatively regulates the target gene TERF2. TERF2 knockdown partly restores miR-29b-1-5p antagomir function in LPS-stimulated HL-1 cells. In summary, miR-29b-1-5p targetedly inhibits TERF2, thereby enhancing sepsis-induced myocardial injury.

Fangji Fuling Decoction Alleviates Sepsis by Blocking MAPK14/FOXO3A Signaling Pathway

OBJECTIVE

To examine the therapeutic effect of Fangji Fuling Decoction (FFD) on sepsis through network pharmacological analysis combined with in vitro and in vivo experiments.

METHODS

A sepsis mouse model was constructed through intraperitoneal injection of 20 mg/kg lipopolysaccharide (LPS). RAW264.7 cells were stimulated by 250 ng/mL LPS to establish an in vitro cell model. Network pharmacology analysis identified the key molecular pathway associated with FFD in sepsis. Through ectopic expression and depletion experiments, the effect of FFD on multiple organ damage in septic mice, as well as on cell proliferation and apoptosis in relation to the mitogen-activated protein kinase 14/Forkhead Box O 3A (MAPK14/FOXO3A) signaling pathway, was analyzed.

RESULTS

FFD reduced organ damage and inflammation in LPS-induced septic mice and suppressed LPS-induced macrophage apoptosis and inflammation in vitro (P<0.05). Network pharmacology analysis showed that FFD could regulate the MAPK14/FOXO signaling pathway during sepsis. As confirmed by in vitro cell experiments, FFD inhibited the MAPK14 signaling pathway or FOXO3A expression to relieve LPS-induced macrophage apoptosis and inflammation (P<0.05). Furthermore, FFD inhibited the MAPK14/FOXO3A signaling pathway to inhibit LPS-induced macrophage apoptosis in the lung tissue of septic mice (P<0.05).

CONCLUSION

FFD could ameliorate the LPS-induced inflammatory response in septic mice by inhibiting the MAPK14/FOXO3A signaling pathway.

Pterostilbene attenuates heart failure by inhibiting myocardial ferroptosis through SIRT1/GSK-3β/GPX4 signaling pathway

Sustained myocardial injury due to hypertension and diabetes mellitus leads to production of endogenous reactive oxygen species (ROS) and insufficient myocardial antioxidant capacity, increasing the risk of cardiomyocyte ferroptosis. Ferroptosis is a nonapoptotic form of cell death driven by unrestricted lipid peroxidation. Dysfunction of the glutathione peroxidase 4 (GPX4) antioxidant system also plays an important role in ferroptosis. Cardiomyocyte ferroptosis ultimately leads to myocardial deterioration, such as inflammation, fibrosis, and cardiac remodeling, resulting in structural and functional changes. Pterostilbene (PTS), a demethylated derivative of resveratrol, exhibits strong anti-inflammatory and antioxidative activities. In this study, we used in vitro experiments to explore ferroptosis induced by angiotensin II (Ang II) of primary cardiac myocytes (CMs) and in vivo experiments to prepare a transverse aortic constriction (TAC)-induced cardiac dysfunction mouse model. PTS can significantly ameliorate Ang II-induced cardiomyocyte ferroptosis in vitro and reduce cardiac remodeling, while improving cardiac function in mice after TAC in vivo. Further mechanistic investigations revealed that PTS exerts its protective effect through the SIRT1/GSK-3β/GPX4 pathway. After siRNA-mediated knockdown of SIRT1 or GPX4 in CMs, the protective effects of PTS on cardiomyocytes were abolished. This study provides important theoretical support for the potential of PTS to attenuate pathological cardiac remodeling and heart failure and provides a preliminary exploration of the molecular pathways involved in its protective mechanism.

Anemonin inhibits sepsis-induced acute kidney injury via mitigating inflammation and oxidative stress

Elevated inflammation and oxidative stress (OS) are the main pathologic features of acute kidney injury (AKI)-caused by sepsis. Here, we made an investigation into the protective effects of the natural compound Anemonin (ANE) on sepsis-induced AKI both in vitro and in vivo. Lipopolysaccharide (LPS) was applied to construct an in vitro AKI model in renal tubular epithelial cells, and the septic C57BL/6J mouse model was constructed via cecal ligation and puncture (CLP). Cell viability and apoptosis were detected. The levels of p53, Bax, Bcl2, Caspase3, Caspase8, Caspase9, AMP-activated protein kinase (AMPK), Sirt-1, and forkhead box O3 were determined by Western Blot or RT-PCR. The reactive oxygen species level and OS markers were measured. Furthermore, the pathological changes of kidneys were evaluated by hematoxylin-eosin staining and immunohistochemistry. As per the information presented, ANE improved LPS-elicited apoptosis, inflammatory response, and OS in a dose-dependent pattern in renal tubular epithelial cells. Besides, ANE activated the AMPK/Sirt-1 pathway, and the AMPK inhibitor (Compound C) and Sirt-1 inhibitor (EX-527) significantly attenuated ANE-mediated protection on renal tubular epithelial cells. In vivo, ANE mitigated the levels of serum creatinine and urea nitrogen in the CLP-induced mouse sepsis model, reduced the renal tissue injury score, and attenuated OS, inflammation, and apoptosis levels in the kidney. Taken together, this study suggested that ANE has protective effects in sepsis-triggered AKI through repressing inflammation, OS, and cell apoptosis by activating the AMPK/Sirt-1 pathway.

Cardiac fibroblast GSK-3α aggravates ischemic cardiac injury by promoting fibrosis, inflammation, and impairing angiogenesis

Myocardial infarction (MI) is the leading cause of death worldwide. Glycogen synthase kinase-3 (GSK-3) has been considered to be a promising therapeutic target for cardiovascular diseases. GSK-3 is a family of ubiquitously expressed serine/threonine kinases. GSK-3 isoforms appear to play overlapping, unique, and even opposing functions in the heart. Previously, our group identified that cardiac fibroblast (FB) GSK-3β acts as a negative regulator of fibrotic remodeling in the ischemic heart. However, the role of FB-GSK-3α in MI pathology is not defined. To determine the role of FB-GSK-3α in MI-induced adverse cardiac remodeling, GSK-3α was deleted specifically in the residential fibroblast or myofibroblast (MyoFB) using tamoxifen (TAM) inducible Tcf21 or Periostin (Postn) promoter-driven Cre recombinase, respectively. Echocardiographic analysis revealed that FB- or MyoFB-specific GSK-3α deletion prevented the development of dilative remodeling and cardiac dysfunction. Morphometrics and histology studies confirmed improvement in capillary density and a remarkable reduction in hypertrophy and fibrosis in the KO group. We harvested the hearts at 4 weeks post-MI and analyzed signature genes of adverse remodeling. Specifically, qPCR analysis was performed to examine the gene panels of inflammation (TNFα, IL-6, IL-1β), fibrosis (COL1A1, COL3A1, COMP, Fibronectin-1, Latent TGF-β binding protein 2), and hypertrophy (ANP, BNP, MYH7). These molecular markers were essentially normalized due to FB-specific GSK-3α deletion. Further molecular studies confirmed that FB-GSK-3α could regulate NF-kB activation and expression of angiogenesis-related proteins. Our findings suggest that FB-GSK-3α plays a critical role in the pathological cardiac remodeling of ischemic hearts, therefore, it could be therapeutically targeted.

Mitochondria-endoplasmic reticulum contacts in sepsis-induced myocardial dysfunction

Mitochondrial and endoplasmic reticulum (ER) are important intracellular organelles. The sites that mitochondrial and ER are closely related in structure and function are called Mitochondria-ER contacts (MERCs). MERCs are involved in a variety of biological processes, including calcium signaling, lipid synthesis and transport, autophagy, mitochondrial dynamics, ER stress, and inflammation. Sepsis-induced myocardial dysfunction (SIMD) is a vital organ damage caused by sepsis, which is closely associated with mitochondrial and ER dysfunction. Growing evidence strongly supports the role of MERCs in the pathogenesis of SIMD. In this review, we summarize the biological functions of MERCs and the roles of MERCs proteins in SIMD.

The β-catenin/CBP signaling axis participates in sepsis-induced inflammatory lung injury

Sepsis-induced inflammatory lung injury is a key factor causing failure of the lungs and other organs, as well as death, during sepsis. In the present study, a caecal ligation and puncture (CLP)-induced sepsis model was established to investigate the effect of β-catenin on sepsis-induced inflammatory lung injury and the corresponding underlying mechanisms. C57BL/6 mice were randomly divided into five groups, namely, the sham, CLP, β-catenin knockout (KO) + CLP, XAV-939 + CLP, and ICG-001 + CLP groups; the XAV-939 + CLP and ICG-001 + CLP groups were separately subjected to intraperitoneal injections of the β-catenin inhibitors XAV-939 and ICG-001 for 1 week preoperatively and 2 days postoperatively, respectively. Forty-eight hours after CLP, we measured β-catenin expression in lung tissues and evaluated mouse mortality, histopathological characteristics of hematoxylin and eosin (H&E)-stained lung tissues, serum cytokine (tumor necrosis factor [TNF]-α, interleukin [IL]-10, and IL-1β) levels, lung myeloperoxidase (MPO) activity, and the number of apoptotic cells in the lung tissues. Our results indicated that both the inhibition of β-catenin expression and blockage of β-catenin/CREB-binding protein (CBP) interactions by ICG-001 effectively decreased mouse mortality, alleviated pathological lung injury, and reduced the serum TNF-α, IL-10, and IL-1β levels, in addition to reducing the lung MPO activity and the number of apoptotic cells in lung tissues of the sepsis model mice. Therefore, it can be deduced that the β-catenin/CBP signaling axis participates in regulating sepsis-induced inflammatory lung injury.

α-Cyperone Protects Cardiomyocytes against Oxygen-Glucose Deprivation-Induced Inflammation and Oxidative Stress by Akt/FOXO3a/NF-κB Pathway

Objective. This study is aimed at investigating the mechanism of α-cyperone in oxygen and glucose deprivation- (OGD-) induced myocardial injury. Methods. Cardiomyocytes were exposed to OGD and then treated with α-cyperone. The cell counting kit-8 (CCK-8) assay and flow cytometry were performed to determine cell proliferation and apoptosis, respectively. The expression of inflammatory factors was monitored by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The profiles of apoptosis-related proteins, inflammatory proteins, and the Akt/FOXO3a/NF-κB pathway were determined by western blot. The phosphorylation of Akt, FOXO3a, and NF-κB was determined by immunofluorescence assay. The superoxide dismutase (SOD) activity and the malondialdehyde (MDA) content were gauged by the colorimetric method, and the reactive oxygen species (ROS) content was measured. Results. α-Cyperone hindered OGD-induced inflammation, oxidative stress, and apoptosis in cardiomyocytes. OGD activated the FOXO3a/NF-κB pathway and hampered the Akt phosphorylation. α-cyperone reversed OGD-mediated FOXO3a/NF-κB pathway activation. Treatment with MK-2206 abated the protective effect of α-cyperone against OGD-induced myocardial injury. The addition of α-cyperone to cardiomyocytes following Bay11-7082 treatment had no conspicuous effect on the viability and apoptosis. Conclusions. α-Cyperone protected cardiomyocytes against OGD-induced inflammation and oxidative stress via the Akt/FOXO3a/NF-κB axis.

Sufentanil Alleviates Sepsis-Induced Myocardial Injury and Stress Response in Rats through the ERK/GSK-3β Signaling Axis

Objective

To explore the effect and possible mechanism of sufentanil on sepsis-induced myocardial injury and stress response in rats.

Methods

The cecal ligation and puncture (CLP) method was utilized to establish the sepsis model of rats to explore the effect of sufentanil pretreatment with different concentrations on myocardial injury and oxidative stress in CLP rats. Echocardiogram was applied for detecting cardiac hemodynamic parameters in rats; hematoxylin and eosin (HE) staining as well as TUNEL staining was done for observing pathological changes of myocardial tissue and cardiomyocyte apoptosis in rats, respectively; biochemical testing and enzyme-linked immunosorbent assay (ELISA) were done for determining myocardial injury marker level in serum, oxidative stress substances in myocardial tissue, and neuroendocrine hormone level in serum of rats, respectively; finally, Western blot was performed for checking the expression level of ERK/GSK-3β signaling pathway-related proteins in myocardial tissue of rats.

Results

A model of rat with sepsis-induced myocardial injury was constructed with the CLP method. Specifically, this rat model was characterized by obvious cardiac function and tissue damage, cardiomyocyte apoptosis, and oxidative stress response. Sufentanil pretreatment significantly improved cardiac function injury, alleviated pathological injury and oxidative stress response in myocardial tissue, and inhibited cardiomyocyte apoptosis. Specifically, after sufentanil pretreatment, left ventricular end-diastolic dimension (LVEDD) and left ventricular end-systolic dimension (LVESD) were downregulated, and left ventricular ejection fraction (LVEF) was upregulated; the level of B-type natriuretic peptide (BNP) of serum, creatine kinase isoenzyme (CK-MB), and troponin (cTnl) decreased; besides, malondialdehyde (MDA) level was declined, while activities of superoxide dismutase (SOD) and catalase (CAT) were increased. What is more, further mechanism exploration also revealed that sufentanil could reverse the activity of the sepsis-induced ERK/GSK-3β signaling pathway.

Conclusion

Sufentanil has an obvious protective effect on myocardial injury and stress response in CLP rats, and this protective effect may be related to the activation of the ERK/GSK-3β signaling pathway.

How vitamin E and its derivatives regulate tumour cells via the MAPK signalling pathway?'

In tumour cells, vitamin E and its derivatives play a critical role in the regulation of multiple signalling pathways through their oxidative and nonoxidative functions. To date, there are 8 known natural vitamin E forms and many kinds of derivatives, among which VES and α-TEA have excellent anticancer activities. The MAPK pathway consists of a complex cascade of proteins that control the proliferation, differentiation and apoptosis of tumour cells. The MAPK pathway includes four subfamilies, ERK1/2, JNK1/2, p38 MAPK, and ERK5. Most of the proteins in these subfamilies interact with each other in a complex manner. The anticancer function of vitamin E and its derivatives is closely related to the MAPK cascade. Studies have shown that in tumour cells, α-T/γ-T/γ-T3/δ-T3/VES/α-TEA regulated ERK1/2, prevent tumorigenesis, inhibit tumour cell growth and metastasis and induce cell differentiation, apoptosis, and cell cycle arrest; γ-T3/δ-T3/VES/α-TEA regulates JNK1/2, induce apoptosis, reduce ceramide synthesis and inhibit proliferation; and γ-T3/δ-T3/VES regulate p38 MAPK and induce apoptosis. This paper reviews the role of vitamin E and its derivatives in the MAPK cascade, and tumour cells are used as a model in an attempt to explore the mechanism of their interactions.

Cardioprotection of M2 macrophages-derived exosomal microRNA-24-3p/Tnfsf10 axis against myocardial injury after sepsis

OBJECTIVE

Some reports have suggested the involvement of microRNA-24-3p (miR-24-3p) in heart diseases. Here, the intention of this work was to unmask whether miR-24-3p from M2 macrophages-derived exosomes (M2-exo) could protect against myocardial injury after sepsis.

METHODS

Mice model of sepsis was induced by intraperitoneal injection of lipopolysaccharide (LPS). miR-24-3p and tumor necrosis factor superfamily member 10 (Tnfsf10) expression levels were measured in the myocardial tissue of septic mice. M2-exo were isolated, in which miR-24-3p expression was altered. Then, septic mice were alone or in combination injected with the miR-24-3p-modified M2-exo or siRNA of Tnfsf10. Subsequently, cardiac function, apoptosis and serum inflammatory response were examined.

RESULTS

miR-24-3p expression dropped while Tnfsf10 expression raised in the myocardial tissue of septic mice. M2-exo-derived miR-24-3p or deficiency of Tnfsf10 had cardioprotective effects on LPS-induced myocardial injury in mice through improving cardiac function and reducing cardiomyocyte apoptosis in the myocardial tissue and serum inflammation. A binding relation exhibited between miR-24-3p and Tnfsf10, and M2-exo-derived miR-24-3p alleviated LPS-induced myocardial injury by inhibiting Tnfsf10.

CONCLUSION

Up-regulating miR-24-3p from M2-exo imposes cardioprotection against myocardial injury after sepsis through reducing Tnfsf10 expression.

Mdivi-1 Modulates Macrophage/Microglial Polarization in Mice with EAE via the Inhibition of the TLR2/4-GSK3β-NF-κB Inflammatory Signaling Axis

Macrophage/microglial modulation plays a critical role in the pathogenesis of multiple sclerosis (MS), which is an inflammatory disorder of the central nervous system. Dynamin-related protein 1 is a cytoplasmic molecule that regulates mitochondrial fission. It has been proven that mitochondrial fission inhibitor 1 (Mdivi-1), a small molecule inhibitor of Drp1, can relieve experimental autoimmune encephalomyelitis (EAE), a preclinical animal model of MS. Whether macrophages/microglia are involved in the pathological process of Mdivi-1-treated EAE remains to be determined. Here, we studied the anti-inflammatory effect of Mdivi-1 on mice with oligodendrocyte glycoprotein peptide_35-55 (MOG_35-55)-induced EAE. We found that Drp1 phosphorylation at serine 616 in macrophages/microglia was decreased with Mdivi-1 treatment, which was accompanied by decreased antigen presentation capacity of the macrophages/microglia in the EAE mouse spinal cord. The Mdivi-1 treatment caused macrophage/microglia to produce low levels of proinflammatory molecules, such as CD16/32, iNOS, and TNF-α, and high levels of anti-inflammatory molecules, such as CD206, IL-10, and Arginase-1, suggesting that Mdivi-1 promoted the macrophage/microglia shift from the inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. Moreover, Mdivi-1 was able to downregulate the expression of TRL2, TRL4, GSK-3β, and phosphorylated NF-κB-p65 and prevent NF-κB-mediated IL-1β and IL-6 production. In conclusion, these results indicate that Mdivi-1 significantly alleviates inflammation in mice with EAE by promoting M2 polarization by inhibiting TLR2/4- and GSK3β-mediated NF-κB activation.

Bone marrow-mesenchymal stem cell-derived exosomal microRNA-141 targets PTEN and activates β-catenin to alleviate myocardial injury in septic mice

BACKGROUND

Mesenchymal stem cells (MSCs) and their derived exosomes have shown potentials in the control of myocardial dysfunction. This study aimed to reveal the function of bone marrow (BM)-MSC-derived exosomes in sepsis-induced myocardial injury and the molecular mechanism.

METHODS

BM-MSC-derived exosomes were obtained and identified. A mouse model with sepsis was induced by cecalligation puncture (CLP) and treated with exosomes. The myocardial function of mice, the production of creatine kinase MB (CK-MB) and lactate dehydrogenase (LDH) in serum, the phosphorylation of a key myocardial contractility-related protein phospholamban (PLB), and the pathological changes in the myocardial tissues were examined. A microRNA (miRNA) microarray analysis was performed to examine the candidate miRNAs carried by the exosomes. Rescue experiments were conducted to validate the involvement of miR-141.

RESULTS

CLP treatment led to sepsis and notably reduced the myocardial function in mice. Further treatment of BM-MSC-derived exosomes alleviated the CLP-induced myocardial impairment, production of CK-MB and LDH, and inflammatory infiltration and cell apoptosis in mouse myocardial tissues, and restored the PLB phosphorylation. miR-141 was the most upregulated miRNA in the myocardial tissues after exosome treatment. Downregulation of miR-141 blocked the myocardium-protective functions of the exosomes. miR-141 was found to bind to and suppress PTEN expression, which further enhanced the activity of β-catenin.

CONCLUSION

This study suggested that BM-MSC derived exosomes ameliorates myocardial injury in septic mice through conveying miRNA-141 and regulating the PTEN/β-catenin axis, and exosomes may serve as promising tools for the management of myocardial injury induced by sepsis or other factors.

Glycogen Synthase Kinase 3β Modulates the Inflammatory Response Activated by Bacteria, Viruses, and Parasites

Knowledge of glycogen synthase kinase 3β (GSK3β) activity and the molecules identified that regulate its function in infections caused by pathogenic microorganisms is crucial to understanding how the intensity of the inflammatory response can be controlled in the course of infections. In recent years many reports have described small molecular weight synthetic and natural compounds, proteins, and interference RNA with the potential to regulate the GSK3β activity and reduce the deleterious effects of the inflammatory response. Our goal in this review is to summarize the most recent advances on the role of GSK3β in the inflammatory response caused by bacteria, bacterial virulence factors (i.e. LPS and others), viruses, and parasites and how the regulation of its activity, mainly its inhibition by different type of molecules, modulates the inflammation.

Glycogen Synthase Kinase 3 (GSK3): Its Role and Inhibitors

Glycogen Synthase Kinase 3 (GSK3) is one of the Serine/Threonine protein kinases, which has gained a lot of attention for its role in a variety of pathways. It has two isoforms, GSK3α and GSK3β. However, GSK3β is highly expressed in different areas of the brain and has been implicated in Alzheimer's disease as it is involved in tau phosphorylation. Due to its high specificity concerning substrate recognition, GSK3 has been considered as an important target. In the last decade, several GSK3 inhibitors have been reported and two molecules are in clinical trials. This review collates the information published in the last decade about the role of GSK3 in Alzheimer's disease and progress in the development of its inhibitors. Using this collated information, medicinal chemists can strategize and design novel GSK3 inhibitors that could be useful in the treatment of Alzheimer's disease.

Beneficial role of oleuropein in sepsis-induced myocardial injury. Possible Involvement of GSK-3β/NF-kB pathway

Purpose

The present study explored the potential therapeutic role of oleuropein in sepsis-induced heart injury along with the role of GSK-3β/NF-kB signaling pathway.

Methods

Sepsis-induced myocardial injury was induced by cecal ligation and puncture (CLP) in rats. The cardiac injury was assessed by measuring the levels of cTnI and creatine kinase-MB (CK-MB). Sepsis-induced inflammation was assessed by measuring interleukin-6 (IL-6), IL-10 and HMGB1 levels. The different doses of oleuropein (5, 10, and 20 mg/kg) were given prior to CLP. Oleuropein (20 mg/kg) was administered after 6 hof CLP. The expressions of GSK-3β, p-GSK-3β (Ser9) and nuclear factor-κB (NF-κB) were measured in heart homogenates.

Results

Cecal ligation and puncture was associated with myocardial injury, an increase in IL-6, a decrease in IL-10 and an increase in HMGB1. Moreover, it decreased the ratio of p-GSK-3β/GSK-3β and increased the expression of p-NF-kB. Pretreatment with oleuropein attenuated CLP-induced myocardial injury and systemic inflammation in a dose-dependent manner. Administration of oleuropein after the onset of CLP also attenuated cardiac injury and inflammation. It also restored CLP-induced changes in the HMGB1 levels, the ratio of p-GSK-3β/GSK-3β and expression of p- NF-kB.

Conclusions

Oleuropein attenuates sepsis-induced systemic inflammation and myocardial injury by inhibiting NF-kB and GSK-3β signaling.

Kcnh2 mediates FAK/AKT-FOXO3A pathway to attenuate sepsis-induced cardiac dysfunction

OBJECTIVES

Myocardial dysfunction is a significant manifestation in sepsis, which results in high mortality. Even Kcnh2 has been hinted to associate with the pathological process, its involved signalling is still elusive.

MATERIALS AND METHODS

The caecal ligation puncture (CLP) surgery or lipopolysaccharide (LPS) injection was performed to induce septic cardiac dysfunction. Western blotting was used to determine KCNH2 expression. Cardiac function was examined by echocardiography 6 hours after CLP and LPS injection in Kcnh2 knockout (Kcnh2+/- ) and NS1643 injection rats (n ≥ 6/group). Survival was monitored following CLP-induced sepsis (n ≥ 8/group).

RESULTS

Sepsis could downregulate KCNH2 level in the rat heart, as well as in LPS-stimulated cardiomyocytes but not cardiac fibroblast. Defect of Kcnh2 (Kcnh2+/- ) significantly aggravated septic cardiac dysfunction, exacerbated tissue damage and increased apoptosis under LPS challenge. Fractional shortening and ejection fraction values were significantly decreased in Kcnh2+/- group than Kcnh2+/+ group. Survival outcome in Kcnh2+/- septic rats was markedly deteriorated, compared with Kcnh2+/+ rats. Activated Kcnh2 with NS1643, however, resulted in opposite effects. Lack of Kcnh2 caused inhibition of FAK/AKT signalling, reflecting in an upregulation for FOXO3A and its downstream targets, which eventually induced cardiomyocyte apoptosis and heart tissue damage. Either activation of AKT by activator or knockdown of FOXO3A with si-RNA remarkably attenuated the pathological manifestations that Kcnh2 defect mediated.

CONCLUSION

Kcnh2 plays a protection role in sepsis-induced cardiac dysfunction (SCID) via regulating FAK/AKT-FOXO3A to block LPS-induced myocardium apoptosis, indicating a potential effect of the potassium channels in pathophysiology of SCID.

Interleukin-5 deletion promotes sepsis-induced M1 macrophage differentiation, deteriorates cardiac dysfunction, and exacerbates cardiac injury via the NF-κB p65 pathway in mice

Inflammation plays a crucial role in sepsis-induced cardiac injury. The purpose of this study was to determine whether interleukin-5 (IL-5) affected lipopolysaccharide (LPS)-induced cardiac injury by regulating the inflammatory response. First, the expression level and source of cardiac IL-5 were examined, and the results showed that LPS treatment and cecal ligation decreased cardiac IL-5 expression in macrophages. In addition, LPS was used to establish a mouse sepsis model, and the effects of IL-5 deletion on cardiac injury, M1 macrophage differentiation and myocardial cell apoptosis were analyzed. The results showed that IL-5 deficiency significantly increased cardiac injury marker expression, worsened cardiac dysfunction, promoted M1 macrophage differentiation and exacerbated myocardial cell apoptosis in LPS-induced septic mice. The nuclear factor-kappa B (NF-κB) p65 pathway was inhibited by JSH-23, and the results showed that treatment with JSH-23 inhibited M1 macrophage differentiation and alleviated cardiac injury in LPS-treated IL-5-knockout mice. Furthermore, the effects of IL-5 deficiency on M1 macrophage differentiation and myocardial cell apoptosis were measured in vitro. The IL-5-mediated promotion of M1 macrophage differentiation was also reversed by S31-201, and the pro-apoptotic effect of IL-5 knockout on macrophage-mediated myocardial cell apoptosis was also reversed by JSH-23. In conclusion, we found that IL-5 knockout may exacerbate sepsis-induced cardiac injury by promoting M1 macrophage differentiation in mice. IL-5 may be a potential target for the clinical prevention of sepsis-related cardiac injury.

miR-29b-3p protects cardiomyocytes against endotoxin-induced apoptosis and inflammatory response through targeting FOXO3A

Cardiac dysfunction represents a main component of death induced by sepsis in critical care units. And microRNAs (miRNAs) have been reported as important modulators or biomarkers of sepsis. However, the molecular detail of miRNAs involved in septic cardiac dysfunction remains unclear. Here we showed that endotoxin (lipopolysaccharide, LPS) significantly down-regulated expression of miR-29b-3p in heart. Increased expression of miR-29b-3p by lentivirus improved cardiac function and attenuated damage of cardiac induced by LPS in mice. Furthermore, overexpression or knockdown of miR-29b-3p showed its crucial roles on regulation of apoptosis and production of pro-inflammatory cytokines in NRCMs through directly targeting FOXO3A. miR-29b-3p ameliorates inflammatory damage likely via reducing activation of MAPKs and nuclear-translocation of NF-κB to block LPS-activated NF-κB signaling. Notably, miR-29b is also down-regulated in septic patients' plasma compared with normal subjects, indicating a potential clinical relevance of miR-29b. Taken together, our findings demonstrate that upregulation of miR-29b-3p can attenuate myocardial injury induced by sepsis via regulating FOXO3A, which provide a potential therapy target for interference of septic cardiac dysfunction.

lncRNA NEAT1 mediates sepsis progression by regulating Irak2 via sponging miR-370-3p

Sepsis is a life-threatening condition and often associated with multiple organ failure. Nuclear-enriched abundant transcript 1 (NEAT1), a member of the long non-coding RNAs (lncRNAs), was reported to be involved in the regulation of sepsis progression. However, its precise regulatory mechanism needs to be further explored. In this study, the cell-counting kit-8 assay was used to check cell viability. The quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expression levels of NEAT1, miR-370-3p and Interleukin 1 receptor associated kinase 2 (Irak2). Flow cytometry assay and ELISA were used to check cell apoptosis and the concentrations of inflammatory cytokines, respectively. The starBase was used to predict binding sites between miR-370-3p and NEAT1 or Irak2 and the dual-luciferase reporter assay was performed to verify the interaction. The protein level of Irak2 in samples was measured by western blot. The high concentration of lipopolysaccharide (LPS) led to the high death ratio of RAW 264.7 and HL-1 cells. NEAT1 and Irak2 were upregulated in sepsis tissues and LPS-induced RAW 264.7 and HL-1 cells, opposite to the expression of miR-370-3p. In addition, knockdown of NEAT1 promoted viability, suppressed apoptosis and reduced the expression of inflammatory cytokines in LPS-induced RAW 264.7 and HL-1 cells. Moreover, we found that miR-370-3p interacted with NEAT1 and targeted the 3'UTR of Irak2. Further research indicated that downregulation of miR-370-3p or upregulation of Irak2 rescued NEAT1 silencing-mediated inhibitory effect on sepsis progression. Knockdown of NEAT1 hampered sepsis progression by downregulating Irak2 via interacting with miR-370-3p in LPS-induced RAW 264.7 and HL-1 cells.

GSK-3β inhibition protects the rat heart from the lipopolysaccharide-induced inflammation injury via suppressing FOXO3A activity

Sepsis-induced cardiac dysfunction represents a main cause of death in intensive care units. Previous studies have indicated that GSK-3β is involved in the modulation of sepsis. However, the signalling details of GSK-3β regulation in endotoxin lipopolysaccharide (LPS)-induced septic myocardial dysfunction are still unclear. Here, based on the rat septic myocardial injury model, we found that LPS could induce GSK-3β phosphorylation at its active site (Y216) and up-regulate FOXO3A level in primary cardiomyocytes. The FOXO3A expression was significantly reduced by GSK-3β inhibitors and further reversed through β-catenin knock-down. This pharmacological inhibition of GSK-3β attenuated the LPS-induced cell injury via mediating β-catenin signalling, which could be abolished by FOXO3A activation. In vivo, GSK-3β suppression consistently improved cardiac function and relieved heart injury induced by LPS. In addition, the increase in inflammatory cytokines in LPS-induced model was also blocked by inhibition of GSK-3β, which curbed both ERK and NF-κB pathways, and suppressed cardiomyocyte apoptosis via activating the AMP-activated protein kinase (AMPK). Our results demonstrate that GSK-3β inhibition attenuates myocardial injury induced by endotoxin that mediates the activation of FOXO3A, which suggests a potential target for the therapy of septic cardiac dysfunction.