SP1-induced ZFAS1 aggravates sepsis-induced cardiac dysfunction via miR-590-3p/NLRP3-mediated autophagy and pyroptosis

Pyroptosis in sepsis induced organ dysfunction

As an uncontrolled inflammatory response to infection, sepsis and sepsis induced organ dysfunction are great threats to the lives of septic patients. Unfortunately, the pathogenesis of sepsis is complex and multifactorial, which still needs to be elucidated. Pyroptosis is a newly discovered atypical form of inflammatory programmed cell death, which depends on the Caspase-1 dependent classical pathway or the non-classical Caspase-11 (mouse) or Caspase-4/5 (human) dependent pathway. Many studies have shown that pyroptosis is related to sepsis. The Gasdermin proteins are the key molecules in the membrane pores formation in pyroptosis. After cut by inflammatory caspase, the Gasdermin N-terminal fragments with perforation activity are released to cause pyroptosis. Pyroptosis is closely related to the occurrence and development of sepsis induced organ dysfunction. In this review, we summarized the molecular mechanism of pyroptosis, the key role of pyroptosis in sepsis and sepsis induced organ dysfunction, with the aim to bring new diagnostic biomarkers and potential therapeutic targets to improve sepsis clinical treatments.

USF2 activates RhoB/ROCK pathway by transcriptional inhibition of miR-206 to promote pyroptosis in septic cardiomyocytes

Septic cardiomyopathy (SCM) is one of the most serious complications of sepsis. The present study investigated the role and mechanism of upstream stimulatory factor 2 (USF2) in SCM. Serum samples were extracted from SCM patients and healthy individuals. A murine model of sepsis was induced by caecal ligation and puncture (CLP) surgery. Myocardial injury was examined by echocardiography and HE staining. ELISA assay evaluated myocardial markers (CK-MB, cTnI) and inflammatory cytokines (TNF-α, IL-1β, IL-18). Primary mouse cardiomyocytes were treated with lipopolysaccharide (LPS) to simulate sepsis in vitro. RT-qPCR and Western blot were used for analyzing gene and protein levels. CCK-8 assay assessed cell viability. NLRP3 was detected by immunofluorescence. ChIP, RIP and dual luciferase reporter assays were conducted to validate the molecular associations. USF2 was increased in serum from SCM patients, septic mice and primary cardiomyocytes. USF2 silencing improved the survival of septic mice and attenuated sepsis-induced myocardial pyroptosis and inflammation in vitro and in vivo. Mechanistically, USF2 could directly bind to the promoter of miR-206 to transcriptionally inhibit its expression. Moreover, RhoB was confirmed as a target of miR-206 and could promote ROCK activation and NLRP3 inflammasome formation. Moreover, overexpression of RhoB remarkably reversed the protection against LPS-induced inflammation and pyroptosis mediated by USF2 deletion or miR-206 overexpression in cardiomyocytes. The above findings elucidated that USF2 knockdown exerted a cardioprotective effect on sepsis by decreasing pyroptosis and inflammation via miR-206/RhoB/ROCK pathway, suggesting that USF2 may be a novel drug target in SCM.

Inhibiting apoptosis and GSDME-mediated pyroptosis attenuates hepatic injury in septic mice

BACKGROUND

Sepsis is characterized by severe inflammation and organ dysfunction resulting from a dysregulated organismal response to infection. Although pyroptosis has been presumably shown to be a major cause of multiple organ failure and septic death, whether gasdermin E (GSDME)-mediated pyroptosis occurs in septic liver injury and whether inhibiting apoptosis and GSDME-mediated pyroptosis can attenuate septic liver injury remain unclear. This study investigated the role of apoptosis and GSDME-mediated pyroptosis in septic liver injury.

METHODS

Adult male C57BL/6 mice were randomly divided into four groups: sham, cecal ligation puncture (CLP), CLP + Z-DEVD-FMK (a caspase-3 inhibitor, 5 mg/kg), and CLP + Ac-DMLD-CMK (a GSDME inhibitor, 5 mg/kg). Sepsis severity was assessed using the murine sepsis score (MSS). Hepatic tissue damage was observed by the hematoxylin-eosin staining method, the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the levels of malondialdehyde (MDA), the concentrations of interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were measured according to the related kits, and the changes in the hepatic tissue reactive oxygen species (ROS) levels were detected by immunofluorescence (IF). The protein expression levels of cleaved caspase-3, GSDME-N, IL-1β, B-cell lymphoma-2 (Bcl-2), cytochrome C (Cyt-c), and acetaldehyde dehydrogenase 2 (ALDH2) were detected using western blotting. GSDME expression was detected by immunohistochemistry.

RESULTS

Compared with the Sham group, CLP mice showed high sepsis scores and obvious liver damage. However, in the CLP + Z-DEVD-FMK and CLP + Ac-DMLD-CMK groups, the sepsis scores were reduced and liver injury was alleviated. Compared with the Sham group, the serum ALT and AST activities, MDA and ROS levels, and IL-1β and TNF-α concentrations were increased in the CLP group, as well as the protein expression of cleaved caspase-3, GSDME-N, IL-1β, Cyt-c, and GSDME positive cells (P < 0.05). However, the expression levels of Bcl-2 and ALDH2 protein were decreased (P < 0.05). Compared with the CLP group, the CLP + Z-DEVD-FMK and CLP + Ac-DMLD-CMK groups showed low sepsis scores, ALT and AST activities, MDA and ROS levels, decreased IL-1β and TNF-α concentrations, and decreased expression of cleaved caspase-3, GSDME-N, IL-1β protein expression, and GSDME positive cells (P < 0.05). The expression levels of Bcl-2 and ALDH2 protein were increased (P < 0.05).

CONCLUSION

Apoptosis and GSDME-mediated pyroptosis are involved in the development of sepsis-induced hepatic injury. Inhibition of apoptosis and GSDME-mediated pyroptosis attenuates injury. ALDH2 plays a protective role by inhibiting apoptosis and pyroptosis.

Apelin ameliorates sepsis-induced myocardial dysfunction via inhibition of NLRP3-mediated pyroptosis of cardiomyocytes

Sepsis-induced myocardial dysfunction (SMD) is the major cause of death in sepsis. Nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3)-mediated pyroptosis contributes to the occurrence and development of SMD. Although Apelin confers direct protection against SMD, the potential mechanisms remain unclear. This study aimed to determine whether Apelin protects against SMD via regulation of NLRP3-mediated pyroptosis of cardiomyocytes. Experimental SMD was induced in wild-type (WT) control mice and Apelin knockout (Apelin-/-) mice by cecal ligation and puncture (CLP). Neonatal mouse cardiomyocytes (NMCs) were treated with lipopolysaccharide (LPS) to simulate the physiological environment of SMD in vitro. The expression of Apelin was greatly decreased in the plasma from septic patients and septic mouse heart. Knockout of Apelin aggravated SMD, evidenced by decreased cardiac function, and increased cardiac fibrosis and NLRP3 inflammasome and pyroptosis levels in CLP-treated Apelin-/- mice compared with WT mice. Overexpression of Apelin activated the AMPK pathway and thereby inhibited NLRP3 inflammasome-mediated pyroptosis of NMCs induced by LPS in vitro These protective effects were partially abrogated by AMPK inhibitor. In conclusion, Apelin attenuated SMD by inhibiting NLRP3-mediated pyroptosis via activation of the AMPK pathway. Apelin may serve as a promising therapeutic target for SMD.

LncRNA Zfas1 boosts cell apoptosis and autophagy in myocardial injury induced by hypoxia via miR-383-5p/ATG10 axis

Background

Myocardial injury has been regarded as a major cause of several heart diseases. Long non-coding RNA (lncRNA) has emerged as a key regulator in a wide array of diseases.

Aim of the study

This study aims to explore the role of Zfas1 in myocardial injury.

Methods

3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was adopted to evaluate the proliferative capability of H9c2 cells. Terminal deoxynucleotidyltransferase dUTP nick end labeling (TUNEL) and flow cytometry assays were employed to measure cell apoptosis. The expression of proteins related to apoptosis and autophagy was examined by Western blot. Immunofluorescence (IF) assay was performed to monitor the process of autophagy. Real-time reverse-transcription polymerase chain reaction (RT-qPCR) was employed to determine the expressions of autophagy-related gene 10 (ATG10), miR-383-5p and Zfas1. The interacting relationship between miR-383-5p and ATG10 (or Zfas1) was assessed by luciferase reporter and RNA-binding protein immunoprecipitation (RIP) assays.

Results

The treatment of hypoxia hindered cell proliferation but accelerated cell apoptosis and autophagy. ATG10 exhibited higher mRNA and protein expression in H9c2 cells induced by hypoxia. MiR-383-5p was revealed to be the upstream gene of ATG10 and could interact with ATG10. Zfas1 was validated to sponge miR-383-5p and positively regulated ATG10 expression. Zfas1 knockdown-mediated cellular proliferation, apoptosis and autophagy phenotypes were counteracted by ATG10 abundance.

Conclusions

LncRNA Zfas1 boosts cell apoptosis and autophagy in myocardial injury induced by hypoxia via miR-383-5p/ATG10 axis, indicating that Zfas1 may be utilized as a therapeutic target for myocardial injury.

SP1-stimulated miR-208a-5p aggravates sepsis-induced myocardial injury via targeting XIAP

The development of sepsis can lead to many organ dysfunction and even death. Myocardial injury is one of the serious complications of sepsis leading to death. New evidence suggests that microRNAs (miRNAs) play a critical role in infection myocardial injury. However, the mechanism which miR-208a-5p regulates sepsis-induced myocardial injury remains unclear. To mimic sepsis-induced myocardial injury in vitro, rat primary cardiomyocytes were treated with LPS. Cell viability and apoptosis were tested by CCK-8 and flow cytometry, respectively. The secretion of inflammatory factors was analyzed by ELISA. mRNA and protein levels were detected by RT-qPCR and Western blotting. The interaction among SP1, XIAP and miR-208a-5p was detected using dual luciferase report assay. Ultrasonic analysis and HE staining was performed to observe the effect of miR-208a-5p in sepsis-induced rats. Our findings indicated that miR-208a-5p expression in primary rat cardiomyocytes was increased by LPS. MiR-208a-5p inhibitor reversed LPS-induced cardiomyocytes injury through inhibiting the apoptosis. Furthermore, the inflammatory injury in cardiomyocytes was induced by LPS, which was rescued by miR-208a-5p inhibitor. In addition, downregulation of miR-208a-5p improved LPS-induced sepsis myocardial injury in vivo. Mechanistically, XIAP might be a target gene of miR-208a-5p. SP1 promoted transcription of miR-208a by binding to the miR-208a promoter region. Moreover, silencing of XIAP reversed the regulatory of miR-208a-5p inhibitor on cardiomyocytes injury. To sum up, those findings revealed silencing of miR-208a-5p could alleviate sepsis-induced myocardial injury, which would grant a new process for the treatment of sepsis.

Protective effect of omega-3 polyunsaturated fatty acids on sepsis via the AMPK/mTOR pathway

CONTEXT

Sepsis is a systemic inflammatory response caused by infection, with high morbidity and mortality. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have reported biological activities.

OBJECTIVE

This study explored the signaling pathways through which ω-3 PUFAs protect against sepsis-induced multiorgan failure.

MATERIALS AND METHODS

Septic Sprague-Dawley (SD) rat model was established by the cecum ligation perforation (CLP) method. Rats were divided into control, sham, model, parenteral ω-3 PUFAs (0.5 g/kg) treatment, ω-3 PUFAs (0.5 g/kg) + AMPK inhibitor Compound C (30 mg/kg) treatment, and ω-3 PUFAs (0.5 g/kg) + mTOR activator MHY1485 (10 mg/kg) treatment groups. The serum inflammatory cytokines were measured using ELISA. Organ damage-related markers cTnI, CK, CK-MB, Cr, BUN, ALT, and AST were measured using an automated chemical analyzer. The AMPK/mTOR pathway in liver, kidney, and myocardial tissues was detected using western blot and qRT-PCR methods.

RESULTS

CLP treatment enhanced the secretion of pro-inflammatory cytokines and multi-organ related markers, along with increased p-AMPK/AMPK ratio (from 0.47 to 0.87) and decreased p-mTOR/mTOR ratio (from 0.33 to 0.12) in rats. The inflammation response and multi-organ injury induced by CLP treatment could be partially counteracted by 0.5 g/kg parenteral ω-3 PUFA treatment. The activated AMPK/mTOR pathway in CLP-induced rats was further promoted. Finally, Compound C and MHY1485 could reverse the effects of parenteral ω-3 PUFA treatment on sepsis rats.

DISCUSSION AND CONCLUSION

ω-3 PUFAs ameliorated sepsis development by activating the AMPK/mTOR pathway, serving as a potent therapeutic agent for sepsis. Further in vivo studies may validate potential clinical use.

Role of toll-like receptor-mediated pyroptosis in sepsis-induced cardiomyopathy

Sepsis, a life-threatening dysregulated status of the host response to infection, can cause multiorgan dysfunction and mortality. Sepsis places a heavy burden on the cardiovascular system due to the pathological imbalance of hyperinflammation and immune suppression. Myocardial injury and cardiac dysfunction caused by the aberrant host responses to pathogens can lead to cardiomyopathy, one of the most critical complications of sepsis. However, many questions about the specific mechanisms and characteristics of this complication remain to be answered. The causes of sepsis-induced cardiac dysfunction include abnormal cardiac perfusion, myocardial inhibitory substances, autonomic dysfunction, mitochondrial dysfunction, and calcium homeostasis dysregulation. The fight between the host and pathogens acts as the trigger for sepsis-induced cardiomyopathy. Pyroptosis, a form of programmed cell death, plays a critical role in the progress of sepsis. Toll-like receptors (TLRs) act as pattern recognition receptors and participate in innate immune pathways that recognize damage-associated molecular patterns as well as pathogen-associated molecular patterns to mediate pyroptosis. Notably, pyroptosis is tightly associated with cardiac dysfunction in sepsis and septic shock. In line with these observations, induction of TLR-mediated pyroptosis may be a promising therapeutic approach to treat sepsis-induced cardiomyopathy. This review focuses on the potential roles of TLR-mediated pyroptosis in sepsis-induced cardiomyopathy, to shed light on this promising therapeutic approach, thus helping to prevent and control septic shock caused by cardiovascular disorders and improve the prognosis of sepsis patients.

NLRP3 inflammasome involves in the pathophysiology of sepsis-induced myocardial dysfunction by multiple mechanisms

Sepsis-induced myocardial dysfunction (SIMD) is one of the serious health-affecting problems worldwide. At present, the mechanisms of SIMD are still not clearly elucidated. The NOD-like receptor protein 3 (NLRP3) inflammasome has been assumed to be involved in the pathophysiology of SIMD by regulating multiple biological processes. NLRP3 inflammasome and its related signaling pathways might affect the regulation of inflammation, autophagy, apoptosis, and pyroptosis in SIMD. A few molecular specific inhibitors of NLRP3 inflammasome (e.g., Melatonin, Ulinastatin, Irisin, Nifuroxazide, and Ginsenoside Rg1, etc.) have been developed, which showed a promising anti-inflammatory effect in a cellular or animal model of SIMD. These experimental findings indicated that NLRP3 inflammasome could be a promising therapeutic target for SIMD treatment. However, the clinical translation of NLRP3 inhibitors for treating SIMD still requires robust in vivo and preclinical trials.

Transcriptome analysis reveals the mechanism of pyroptosis-related genes in septic cardiomyopathy

Background

Septic cardiomyopathy (SC) is characterized by myocardial dysfunction caused by sepsis and constitutes one of the serious complications of sepsis. Pyroptosis is a unique proinflammatory programmed cell death process. However, the role of pyroptosis in the development of SC remains unclear, and further study is required. The purpose of this study is to identify pyroptosis-related genes (PRGs) in SC and explore the mechanism of pyroptosis involved in the regulation of SC formation and progression.

Methods

Differential expression analysis and enrichment analysis were performed on the SC-related dataset GSE79962 to identify differentially expressed genes (DEGs). PRGs were screened by intersecting genes associated with pyroptosis in previous studies with the DEGs obtained from GSE79962. The expression pattern of them was studied based on their raw expression data. Additionally, corresponding online databases were used to predict miRNAs, transcription factors (TFs) and therapeutic agents of PRGs. Lipopolysaccharide (LPS)-induced cell damage models in H9C2 and AC16 cell lines were constructed, cell activity was detected by CCK-8 and cell pyroptosis were detected by Hoechst33342/PI staining. Furthermore, these PRGs were verified in the external datasets (GSE53007 and GSE142615) and LPS-induced cell damage model. Finally, the effect of siRNA-mediated PRGs knockdown on the pyroptosis phenotype was examined.

Results

A total of 1,206 DEGs were screened, consisting of 663 high-expressed genes and 543 low-expressed genes. Among them, ten PRGs (SOD2, GJA1, TIMP3, TAP1, TIMP1, NOD1, TP53, CPTP, CASP1 and SAT1) were identified, and they were mainly enriched in "Pyroptosis", "Ferroptosis", "Longevity regulating pathway", and "NOD-like receptor signaling pathway". A total of 147 miRNAs, 31 TFs and 13 therapeutic drugs were predicted targeting the PRGs. The expression trends of SOD2 were confirmed in both the external datasets and LPS-induced cell damage models. Knockdown of SOD2 induced increased pyroptosis in the AC16 LPS-induced cell damage model.

Conclusions

In this study, we demonstrated that SOD2 is highly expressed in both the SC and LPS-induced cell damage models. Knockdown of SOD2 led to a significant increase in pyroptosis in the AC16 LPS-induced cell damage model. These findings suggest that SOD2 may serve as a potential target for the diagnosis and treatment of SC.

NUCLEOLIN PROMOTES AUTOPHAGY THROUGH PGC-1Α IN LPS-INDUCED MYOCARDIAL INJURY

ABSTRACT

As a multifunctional protein, nucleolin can participate in a variety of cellular processes. Nucleolin also has multiple protective effects on heart disease. Previous studies have shown that nucleolin could not only resist oxidative stress damage and inflammatory damage, but also regulate autophagy to play a protective role in cardiac ischemia. However, the specific mechanism has not been fully elucidated in LPS-induced myocardial injury. Therefore, the aim of this study is to explore the underlying mechanism by which nucleolin regulates autophagy to protect against LPS-induced myocardial injury in vivo and in vitro . In our study, we found that nucleolin could bind to PGC-1α, and we predicted that this interaction could promote autophagy and played a role in inhibiting cardiomyocyte apoptosis. Downregulation of nucleolin in H9C2 cells resulted in decreased autophagy and increased cell apoptosis during LPS-induced myocardial injury, while upregulation of PGC-1α had the opposite protective effect. Upregulation of nucleolin expression in cardiomyocytes could increase the level of autophagy during LPS-induced myocardial injury. In contrast, interference with PGC-1α expression resulted in a decrease in the protective effect of nucleolin, leading to reduced autophagy and thus increasing apoptosis. By using tandem fluorescent-tagged LC3 autophagic flux detection system, we observed autophagic flux and determined that PGC-1α interference could block autophagic lysosomal progression. We further tested our hypothesis in the nucleolin cardiac-specific knockout mice. Finally, we also found that inhibition of autophagy can reduce mitochondrial biogenesis as well as increase apoptosis, which demonstrated the importance of autophagy. Therefore, we can speculate that nucleolin can protect LPS-induced myocardial injury by regulating autophagy, and this protective effect may be mediated by the interaction with PGC-1α, which can positively regulate the ULK1, an autophagy-related protein. Our study provides a new clue for the cardioprotective effect of nucleolin, and may provide new evidence for the treatment of LPS-induced myocardial injury through the regulation of autophagy.

mTOR in programmed cell death and its therapeutic implications

Mechanistic target of rapamycin (mTOR), a highly conserved serine/threonine kinase, is involved in cellular metabolism, protein synthesis, and cell death. Programmed cell death (PCD) assists in eliminating aging, damaged, or neoplastic cells, and is indispensable for sustaining normal growth, fighting pathogenic microorganisms, and maintaining body homeostasis. mTOR has crucial functions in the intricate signaling pathway network of multiple forms of PCD. mTOR can inhibit autophagy, which is part of PCD regulation. Cell survival is affected by mTOR through autophagy to control reactive oxygen species production and the degradation of pertinent proteins. Additionally, mTOR can regulate PCD in an autophagy-independent manner by affecting the expression levels of related genes and phosphorylating proteins. Therefore, mTOR acts through both autophagy-dependent and -independent pathways to regulate PCD. It is conceivable that mTOR exerts bidirectional regulation of PCD, such as ferroptosis, according to the complexity of signaling pathway networks, but the underlying mechanisms have not been fully explained. This review summarizes the recent advances in understanding mTOR-mediated regulatory mechanisms in PCD. Rigorous investigations into PCD-related signaling pathways have provided prospective therapeutic targets that may be clinically beneficial for treating various diseases.

Inflammatory mechanisms and intervention strategies for sepsis-induced myocardial dysfunction

Sepsis-induced myocardial dysfunction (SIMD) is the leading cause of death in patients with sepsis in the intensive care units. The main manifestations of SIMD are systolic and diastolic dysfunctions of the myocardium. Despite our initial understanding of the SIMD over the past three decades, the incidence and mortality of SIMD remain high. This may be attributed to the large degree of heterogeneity among the initiating factors, disease processes, and host states involved in SIMD. Previously, organ dysfunction caused by sepsis was thought to be an impairment brought about by an excessive inflammatory response. However, many recent studies have shown that SIMD is a consequence of a combination of factors shaped by the inflammatory responses between the pathogen and the host. In this article, we review the mechanisms of the inflammatory responses and potential novel therapeutic strategies in SIMD.

Myo-inositol oxygenase (MIOX) accelerated inflammation in the model of infection-induced cardiac dysfunction by NLRP3 inflammasome

BACKGROUND

Cardiac dysfunction is an important component of multiple organ failure caused by sepsis, and an important cause of high mortality in patients with sepsis. Herein, we attempted to determine whether myo-inositol oxygenase (MIOX) has proinflammation enzyme in infection-induced cardiac dysfunction (IICD) and its underlying mechanism.

METHODS

Patients with IICD were collected by our hospital. A mouse model of IICD was induced into male db/db mice by cecal ligation and puncture (CLP). All mice were injected with 20 μL of LV-MIOX or LV-control short hairpin RNA using a 0.5-mL insulin syringe. On the second day, all mice were induced by CLP. H9C2 cell was also induced with lipopolysaccharide and adenosine triphosphate. Quantitative analysis of messenger RNAs (mRNAs) and gene microarray hybridization was used to analyze the mRNA expression levels. Enzyme-linked immunosorbent assay, immunofluorescence, and Western blot analysis were used to analyze the protein expression levels.

RESULTS

The serum expressions of MIOX mRNA level in patients with IICD were upregulated compared to normal healthy volunteers. MIOX promoted inflammation levels in the in vitro model of IICD. Si-MIOX inhibited inflammation levels in the in vitro model of IICD. MIOX accelerated inflammation and cardiac dysfunction in infection-induced mice. MIOX interacted with NLR family pyrin domain containing 3 (NLRP3) protein to reduce the degradation of NLRP3. The inhibition of MIOX reversed the effects of NLRP3 in the in vitro model of cardiac dysfunction.

CONCLUSIONS

Taken together, these findings demonstrate that MIOX accelerates inflammation in the model of IICD, which may be, at least in part, attributable to NLRP3 activity by the suppression of NLRP3 degradation in IICD.

Effect of LSD1 on osteogenic differentiation of human periodontal ligament stem cells in periodontitis

OBJECTIVE

Periodontitis is a chronic inflammation of periodontal tissues. This study is expected to assess the effect of LSD1 on the osteogenic differentiation of hPDLSCs in periodontitis.

METHODS

hPDLSCs were separated, cultivated, and identified, and then treated by LPS to induce inflammatory microenvironment and subjected to osteogenic differentiation. Subsequently, LSD1 expression was determined, and then silenced to assess its effect on hPDLSCs. Next, the binding relation between LSD1 and miR-590-3p was analyzed. miR-590-3p expression was detected and then overexpressed to evaluate its role in hPDLSCs in periodontitis. Afterward, the relation between LSD1 and OSX was analyzed. H3K4me2 level and OSX transcription were measured, and the role of H3K4me2 was determined. Additionally, the role of OSX in hPDLSCs was verified.

RESULTS

LSD1 was poorly expressed after osteogenic differentiation of hPDLSCs while it was rescued upon LPS induction. The osteogenic differentiation of hPDLSC in periodontitis was strengthened upon LSD1 downregulation. Besides, miR-590-3p targeted LSD1 transcription, and LSD1 inhibited OSX transcription via H3K4me2 demethylation. miR-590-3p overexpression improved osteogenic differentiation of hPDLSCs in periodontitis. But this improvement was annulled by OSX inhibition.

CONCLUSION

miR-590-3p targeted LSD1 transcription and upregulated H3K4me2 methylation to promote OSX transcription, thereby encouraging osteogenic differentiation of hPDLSCs in periodontitis.

Lycorine protects against septic myocardial injury by activating AMPK-related pathways

Cardiac dysfunction is a common complication in patients with sepsis triggering high morbidity and mortality. Lycorine (LYC), the main effective monomer component extracted from Lycoris bulbs, possesses antiviral, anti-inflammatory, analgesic, liver protection properties. In this study, the effect of LYC pre- and post-treatment as well as the underlying mechanism were evaluated in the cecal ligation and puncture (CLP) model of Balb/c mice. The survival rate, anal temperature, sepsis score, blood biochemical/routine indicators, cardiac function, sepsis-related pathophysiological processes, and AMPK signaling in septic mice were observed by echocardiography, histological staining, western blot, qPCR, and etc. LYC pretreatment attenuated myocardial injury in septic mice by improving survival rate, sepsis score, blood biochemical/routine indicators, cardiac function and structure, inhibiting inflammation and oxidative stress, improving mitochondrial function, modulating endoplasmic reticulum stress, and activating AMPK pathway. In particular, AMPK deficiency and AMPK inhibitor (Compound C) partially reversed the protective effects of LYC in septic mice. In addition, LYC posttreatment also has slight protective phenotypes on septic myocardial injury, but the effect is not as ideal as pretreatment. Taken together, these findings suggest that LYC may be a potential drug for the treatment of sepsis.

SCREENING OF POTENTIAL CORE GENES IN PERIPHERAL BLOOD OF ADULT PATIENTS WITH SEPSIS BASED ON TRANSCRIPTION REGULATION FUNCTION

ABSTRACT

Objective: The aim of the study is to screen transcription factor genes related to the prognosis of adult patients with sepsis. Methods: Twenty-three patients with sepsis and 10 healthy individuals admitted for RNA-seq. Differential factors were enriched by four transcription factor databases, and survival analysis was adopted for core factors. Then, target genes were submitted to STRING to constitute the protein-protein interaction network. Single-cell technology was used to localize cell lines. Finally, a transcription-target gene regulation network was constituted. Results: A total of 4,224 differentially expressed genes were obtained between sepsis and normal control groups. Protein-protein interaction results showed that FOXO3, NFKB1, SPI1, STAT5A, and PPARA were located in the center of the network. Target genes were related to cytokine-mediated signaling pathway and transcription regulator activity, etc. SPI1 was mainly located in monocyte cell lines, while FOXO3, PPARA, SP1, STAT3, and USF1 were expressed in monocyte cell lines, NK-T cell lines, and B cell lines. Compared with those in the control group, FOXO3, SP1, SPI1, STAT3, and USF1 were highly expressed in the sepsis group, while PPARA had low expression. Conclusions: Transcription factors, such as FOXO3, PPARA, SP1, SPI1, STAT3, and USF1, are correlated with the prognosis of sepsis patients and thus may have a potential research value. Clinical Trial Registration: The clinical trial registration number is ChiCTR1900021261.

Circulatory long noncoding RNAs (circulatory-LNC-RNAs) as novel biomarkers and therapeutic targets in cardiovascular diseases: Implications for cardiovascular diseases complications

Cardiovascular diseases (CVDs) are a group of disorders with major global health consequences. The prevalence of CVDs continues to grow due to population-aging and lifestyle modifications. Non-coding RNAs (ncRNAs) as key regulators of cell signaling pathways have gained attention in the occurrence and development of CVDs. Exosomal-lncRNAs (exos-lncRNAs) are emerging biomarkers due to their high sensitivity and specificity, stability, accuracy and accessibility in the biological fluids. Recently, circulatory and exos-based-lncRNAs are emerging and novel bio-tools in various pathogenic conditions. It is worth mentioning that dysregulation of these molecules has been found in different types of CVDs. In this regard, we aimed to discuss the knowledge gaps and suggest research priorities regarding circulatory and exos-lncRNAs as novel bio-tools and therapeutic targets for CVDs.

Vitamin C alleviates LPS-induced myocardial injury by inhibiting pyroptosis via the ROS-AKT/mTOR signalling pathway

BACKGROUND

The efficacy of vitamin C in sepsis remains controversial. Whether vitamin C can alleviate lipopolysaccharide (LPS)-induced myocardial injury by inhibiting pyroptosis has not been studied. This study aimed to evaluate the effects of vitamin C on LPS-induced myocardial injury in vitro.

METHODS

H9C2 cells were treated with indicated concentrations of LPS, and the cell viability was then assessed by CCK-8 assay. The levels of lactate dehydrogenase (LDH), CK-MB, IL-18 and IL-1β were examined by enzyme-linked immunosorbent assay (ELISA). The levels of intracellular reactive oxygen species (ROS) were measured using the fluorescent probe dichlorodihydrofluorescein diacetate (DCFH-DA). Western blot assays were conducted to determine the levels of the ROS-associated protein nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) and pyroptosis-associated proteins, such as NOD-like receptor (NLR) family pyrin domain containing 3 (NLRP3), caspase-1 and gasdermin D (GSDMD). The AKT inhibitor MK-2206 was then applied to explore the signalling pathway. Finally, H9C2 cells were divided into the control group, LPS group, vitamin C + LPS group, and N-acetyl-L-cysteine (NAC) + LPS group. The intracellular ROS, levels of associated proteins, cell viability, and release of LDH, CK-MB, IL-18 and IL-1β were examined.

RESULTS

LPS decreased cell viability and induced ROS and pyroptosis in H9C2 cells in a dose-dependent manner. Moreover, LPS activated the AKT/mTOR pathway in H9C2 cells. The AKT inhibitor MK-2206 protected H9C2 cells from LPS-induced death by suppressing pyroptosis, without changing intracellular ROS level. Vitamin C significantly inhibited intracellular ROS and cell pyroptosis in LPS-treated H9C2 cells. Moreover, vitamin C suppressed the activation of the AKT/mTOR pathway.

CONCLUSIONS

Our data suggest that vitamin C alleviates LPS-induced myocardial injury by inhibiting pyroptosis via the ROS-AKT/mTOR signalling pathway and thus provide novel insights into the prevention of sepsis-induced myocardial dysfunction.

The multifunctional roles of autophagy in the innate immune response: Implications for regulation of transplantation rejection

Organ transplantation is the main treatment for end-stage organ failure, which has rescued tens of thousands of lives. Immune rejection is the main factor affecting the survival of transplanted organs. How to suppress immune rejection is an important goal of transplantation research. A graft first triggers innate immune responses, leading to graft inflammation, tissue injury and cell death, followed by adaptive immune activation. At present, the importance of innate immunity in graft rejection is poorly understood. Autophagy, an evolutionarily conserved intracellular degradation system, is proven to be involved in regulating innate immune response following graft transplants. Moreover, there is evidence indicating that autophagy can regulate graft dysfunction. Although the specific mechanism by which autophagy affects graft rejection remains unclear, autophagy is involved in innate immune signal transduction, inflammatory response, and various forms of cell death after organ transplantation. This review summarizes how autophagy regulates these processes and proposes potential targets for alleviating immune rejection.

Study on the protective effect of berberine treatment on sepsis based on gut microbiota and metabolomic analysis

Introduction

Sepsis, an infection with multiorgan dysfunction, is a serious burden on human health. Berberine (BBR), a bioactive component, has a protective effect on sepsis and the effect may be related to gut microbiota. However, studies on the role of BBR with gut microbiota in sepsis are lacking. Therefore, this study investigated the ameliorative effects and the underlying mechanisms of BBR on cecal ligature and puncture (CLP) rats.

Methods

This study has observed the effect of BBR on pathological injury, Inflammation, intestinal barrier function, gut microbiota, and metabolite change in CLP rats by Hematoxylin-eosin staining, enzyme-linked immunosorbent assays, flow cytometry, 16S rDNA, and metabolomics analyses.

Results

The inhibition effects of BBR treatment on the histological damage of the lung, kidney, and ileum, the interleukin (IL)-1b, IL-6, IL-17A, and monocyte chemokine-1 levels in serum in CLP rats were proved. Also, the BBR inhibited the diamine-oxidase and fluorescein isothiocyanate-dextran 40 levels, suggesting it can improve intestinal barrier function disorders. The cluster of differentiation (CD) 4⁺, CD8⁺, and CD25⁺ Forkhead box protein P3 (Foxp3) + T lymphocytes in splenocytes were up-regulated by BBR, while the IL-17A+CD4+ cell level was decreased. The abundance of gut microbiota in CLP rats was significantly different from that of the sham and BBR treatment rats. The significantly changed metabolites in the serum mainly included carbohydrates, phenols, benzoic acids, alcohols, vitamins et al. Additionally, this study predicted that the biological mechanism of BBR to ameliorate sepsis involves glycolysis-, nucleotide-, and amino acid-related metabolic pathways.

Discussion

This study proved the strong correlation between the improvement effect of BBR on sepsis and gut microbiota and analyzed by metabolomics that gut microbiota may improve CLP rats through metabolites, providing a scientific basis for BBR to improve sepsis and a new direction for the study of the biological mechanism.

Jujuboside A attenuates sepsis-induced cardiomyopathy by inhibiting inflammation and regulating autophagy

BACKGROUND

Jujuboside A (JuA), as a main effective component of Jujubogenin, has long been known as a sedative-hypnotic drug. The aim of the current study was to investigate the potential effect of JuA on sepsis-induced cardiomyopathy (SIC) induced by lipopolysaccharide (LPS).

METHOD

Wide type C57BL/6 mice and neonatal rat cardiomyocytes (NRCMs) were exposed to LPS to establish myocardial toxicity models. Cardiac function of septic mice was detected by echocardiography. Moreover, the survival rate was calculated for 7 days. ELISA assays were used to analyze inflammatory factors in serum. Furthermore, western blotting, flow cytometry and TUNEL staining were performed to assess cell apoptosis and transmission electron microscopy detect the number of autophagosomes in myocardium. Finally, the expression of proteins related to pyroptosis, autophagy and oxidative stress was analyzed by western blotting and immunohistochemistry staining.

RESULTS

Results showed that JuA pretreatment significantly improved the survival rate and cardiac function, and suppressed systemic inflammatory response in septic mice. Further study revealed that JuA could decrease cell apoptosis and pyroptosis; instead, it strengthened autophagy in SIC. Moreover, JuA also significantly decreased oxidative stress and nitrodative stress, as evidenced by suppressing the superoxide production and downregulating iNOS and gp91 expression in vivo. In addition, the autophagy inhibitor 3-MA significantly abolished the effect of JuA on autophagic activity in SIC.

CONCLUSION

In conclusion, the findings indicated that JuA attenuates cardiac function via blocking inflammasome-mediated apoptosis and pyroptosis, at the same time by enhancing autophagy in SIC, heralding JuA as a potential therapy for sepsis.

Pyroptosis is a drug target for prevention of adverse cardiac remodeling: The crosstalk between pyroptosis, apoptosis, and autophagy

Acute myocardial infarction (AMI) is one of the main reasons of cardiovascular disease-related death. The introduction of percutaneous coronary intervention to clinical practice dramatically decreased the mortality rate in AMI. Adverse cardiac remodeling is a serious problem in cardiology. An increase in the effectiveness of AMI treatment and prevention of adverse cardiac remodeling is difficult to achieve without understanding the mechanisms of reperfusion cardiac injury and cardiac remodeling. Inhibition of pyroptosis prevents the development of postinfarction and pressure overload-induced cardiac remodeling, and mitigates cardiomyopathy induced by diabetes and metabolic syndrome. Therefore, it is reasonable to hypothesize that the pyroptosis inhibitors may find a role in clinical practice for treatment of AMI and prevention of cardiac remodeling, diabetes and metabolic syndrome-triggered cardiomyopathy. It was demonstrated that pyroptosis interacts closely with apoptosis and autophagy. Pyroptosis could be inhibited by nucleotide-binding oligomerization domain-like receptor with a pyrin domain 3 inhibitors, caspase-1 inhibitors, microRNA, angiotensin-converting enzyme inhibitors, angiotensin Ⅱ receptor blockers, and traditional Chinese herbal medicines.

Exosomal transfer of microRNA-590-3p between renal tubular epithelial cells after renal ischemia-reperfusion injury regulates autophagy by targeting TRAF6

BACKGROUND

Acute kidney injury (AKI) is a common complication in patients, especially elderly patients, who undergo cardiac surgery with cardiopulmonary bypass. Studies have indicated a protective role of autophagy in AKI. However, the mechanisms underlying the regulatory effect of autophagy in AKI among patients undergoing cardiac surgeries are poorly understood. In this study, we aimed to test the hypothesis that exosomal microRNAs (miRNAs) regulate autophagy in tubular epithelial cells after AKI.

METHODS

Plasma exosomal RNA was extracted from young and elderly AKI patients undergoing cardiac surgery, and the miRNAs expression during the perioperative period were analyzed using next-generation sequencing. The screened miRNAs and their target genes were subjected to gene oncology function and Kyoto Encyclopedia of Genes and Genome enrichment analyses. Renal tubular epithelial cell line (HK-2 cells) was cultured and hypoxia/reoxygenation (H/R) model was established, which is an in vitro renal ischemia/reperfusion (I/R) model. We used Western blot analysis, cell viability assay, transfection, luciferase assay to investigate the mechanisms underlying the observed increases in the levels of renal I/R injury-mediated exosomal miRNAs and their roles in regulating HK-2 cells autophagy.

RESULTS

miR-590-3p was highly enriched in the plasma exosomes of young AKI patients after cardiac surgery. Increased levels of miR-590-3p led to the increases in the expression of autophagy marker proteins, including Beclin-1 and microtubule associated protein 1 light chain 3 beta (LC3II), and prolonged the autophagic response in HK-2 cells after H/R treatment. These effects were achieved mainly via increases in the exosomal miR-590-3p levels, and the tumor necrosis factor receptor-associated factor 6 protein was shown to play a key role in I/R injury-mediated autophagy induction.

CONCLUSION

Exosomes released from HK-2 cells after renal I/R injury regulate autophagy by transferring miR-590-3p in a paracrine manner, which suggests that increasing the miR-590-3p levels in HK-2 cell-derived exosomes may increase autophagy and protect against kidney injury after renal I/R injury.

LINC01526 Promotes Proliferation and Metastasis of Gastric Cancer by Interacting with TARBP2 to Induce GNG7 mRNA Decay

Simple Summary

Many long noncoding RNAs play an important role in gastric cancer progression. In this study, we focused on LINC01526. Through expression and functional analyses, we obtained a preliminary understanding of the pro-cancer role of LINC01526 in gastric cancer. Furthermore, RNA pull-down and RNA immunoprecipitation chip assays demonstrated that LINC01526 interacts with TARBP2, an RNA-binding protein controlling mRNA stability. Moreover, TARBP2 could bind and destabilize GNG7 transcripts. Finally, the rescue assay disclosed that LINC01526 promoted gastric cancer progression by interacting with TARBP2, leading to the degradation of GNG7 mRNA.

Abstract

Gastric cancer is the most common malignancy of the human digestive system. Long noncoding RNAs (lncRNAs) influence the occurrence and development of gastric cancer in multiple ways. However, the function and mechanism of LINC01526 in gastric cancer remain unknown. Herein, we investigated the function of LINC01526 with respect to the malignant progression of gastric cancer. We found that LINC01526 was upregulated in gastric cancer cells and tissues. The function experiments in vitro and the Xenograft mouse model in vivo proved that LINC01526 could promote gastric cancer cell proliferation and migration. Furthermore, LINC01526 interacted with TAR (HIV-1) RNA-binding protein 2 (TARBP2) and decreased the mRNA stability of G protein gamma 7 (GNG7) through TARBP2. Finally, the rescue assay showed that downregulating GNG7 partially rescued the cell proliferation inhibited by LINC01526 or TARBP2 silencing. In summary, LINC01526 promoted gastric cancer progression by interacting with TARBP2, which subsequently degraded GNG7 mRNA. This study not only explores the role of LINC01526 in gastric cancer, but also provides a laboratory basis for its use as a new biomarker for diagnosis and therapeutic targets.

Crosstalk between regulated necrosis and micronutrition, bridged by reactive oxygen species

The discovery of regulated necrosis revitalizes the understanding of necrosis from a passive and accidental cell death to a highly coordinated and genetically regulated cell death routine. Since the emergence of RIPK1 (receptor-interacting protein kinase 1)-RIPK3-MLKL (mixed lineage kinase domain-like) axis-mediated necroptosis, various other forms of regulated necrosis, including ferroptosis and pyroptosis, have been described, which enrich the understanding of pathophysiological nature of diseases and provide novel therapeutics. Micronutrients, vitamins, and minerals, position centrally in metabolism, which are required to maintain cellular homeostasis and functions. A steady supply of micronutrients benefits health, whereas either deficiency or excessive amounts of micronutrients are considered harmful and clinically associated with certain diseases, such as cardiovascular disease and neurodegenerative disease. Recent advance reveals that micronutrients are actively involved in the signaling pathways of regulated necrosis. For example, iron-mediated oxidative stress leads to lipid peroxidation, which triggers ferroptotic cell death in cancer cells. In this review, we illustrate the crosstalk between micronutrients and regulated necrosis, and unravel the important roles of micronutrients in the process of regulated necrosis. Meanwhile, we analyze the perspective mechanism of each micronutrient in regulated necrosis, with a particular focus on reactive oxygen species (ROS).

The combination of high glucose and LPS induces autophagy in bovine kidney epithelial cells via the Notch3/mTOR signaling pathway

BACKGROUND

Aside respiratory diseases, beef cattle may also suffer from serious kidney diseases after transportation. Hyperglycemia and gram-negative bacterial infection may be the main reasons why bovine is prone to severe kidney disease during transportation stress, however, the precise mechanism is still unclear. The purpose of the current study is to explore whether the combined treatment of high glucose (HG) and lipopolysaccharide (LPS) could induce madin-darby bovine kidney (MDBK) cells injury and autophagy, as well as investigate the potential molecular mechanisms involved.

RESULTS

As we discovered, the combined effect of HG and LPS decreased MDBK cells viability. And, HG and LPS combination also induced autophagy in MDBK cells, which was characterized by increasing the expression of LC3-II/I and Beclin1 and decreasing p62 expression. LC3 fluorescence signal formation was also significantly increased by HG and LPS combination treatment. Furthermore, we measured whether the mammalian target of rapamycin (mTOR) and the Notch3 signaling pathways were involved in HG and LPS-induced autophagy. The results showed that the combination of HG and LPS significantly increased the protein expression of Notch3 and decreased protein expression of p-mTOR, indicating that Notch3 and mTOR signaling pathways were activated. However, co-treatment with the Notch3 inhibitor (DAPT) could reverse the induction of autophagy, and increased the protein expression of p-mTOR.

CONCLUSIONS

This study demonstrated that the combination effect of HG and LPS could induce autophagy in MDBK cells, and the Notch3/mTOR signaling pathway was involved in HG and LPS-induced autophagy.

Non-coding RNAs in necroptosis, pyroptosis, and ferroptosis in cardiovascular diseases

Accumulating evidence has proved that non-coding RNAs (ncRNAs) play a critical role in the genetic programming and gene regulation of cardiovascular diseases (CVDs). Cardiovascular disease morbidity and mortality are rising and have become a primary public health issue that requires immediate resolution through effective intervention. Numerous studies have revealed that new types of cell death, such as pyroptosis, necroptosis, and ferroptosis, play critical cellular roles in CVD progression. It is worth noting that ncRNAs are critical novel regulators of cardiovascular risk factors and cell functions by mediating pyroptosis, necroptosis, and ferroptosis. Thus, ncRNAs can be regarded as promising therapeutic targets for treating and diagnosing cardiovascular diseases. Recently, there has been a surge of interest in the mediation of ncRNAs on three types of cell death in regulating tissue homeostasis and pathophysiological conditions in CVDs. Although our understanding of ncRNAs remains in its infancy, the studies reviewed here may provide important new insights into how ncRNAs interact with CVDs. This review summarizes what is known about the functions of ncRNAs in modulating cell death-associated CVDs and their role in CVDs, as well as their current limitations and future prospects.

Astragalus mongholicus Bunge-Curcuma aromatica Salisb. suppresses growth and metastasis of colorectal cancer cells by inhibiting M2 macrophage polarization via a Sp1/ZFAS1/miR-153-3p/CCR5 regulatory axis

Colorectal cancer (CRC) is regarded as one of the commonest cancer types around the world. Due to the poor understanding on the causes of CRC formation and progression, this study sets out to investigate the physiological mechanisms by which Astragalus mongholicus Bunge-Curcuma aromatica Salisb. (ARCR) regulates CRC growth and metastasis, and the role in which M2 macrophage polarization plays in this process. An orthotopic-transplant model of CRC was established to evaluate the influence of ARCR on the polarization of M2 macrophage and the growth and metastasis of tumors. Next, the binding affinity among Sp1, ZFAS1, miR-153-5p, and CCR5 was identified using multiple assays. Finally, after co-culture of bone marrow-derived macrophages (BMDM) with CRC cell line CT26.WT, the cell proliferative, invasive, and migrated abilities were assessed in gain- or loss-of-function experiments. ARCR inhibited the infiltration of M2 macrophages into tumor microenvironment to suppress the CRC growth and metastasis in vivo. Additionally, ARCR inhibited the transcription of ZFAS1 by reducing Sp1 expression to repress M2 macrophage polarization. Moreover, ZFAS1 competitively binds to miR-153-3p to upregulate the CCR5 expression. Finally, ARCR suppressed the polarization of M2 macrophages to inhibit the tumor growth and tumor metastasis in CRC by mediating the Sp1/ZFAS1/miR-153-3p/CCR5 regulatory axis. Collectively, ARCR appears to suppress the CRC cell growth and metastasis by suppressing M2 macrophage polarization via Sp1/ZFAS1/miR-153-3p/CCR5 regulatory axis. 1. ARCR suppress the CRC cell growth and metastasis 2. ZFAS1 promotes CCR5 expression by competitively binding to miR-153-3p. 3. Sp1 promotes M2 macrophage polarization by activating ZFAS1 via miR-153-3p/CCR5. 4. The study unveiled a protective target against CRC.

Cardiomyocyte death in sepsis: Mechanisms and regulation (Review)

Sepsis‑induced cardiac dysfunction is one of the most common types of organ dysfunction in sepsis; its pathogenesis is highly complex and not yet fully understood. Cardiomyocytes serve a key role in the pathophysiology of cardiac function; due to the limited ability of cardiomyocytes to regenerate, their loss contributes to decreased cardiac function. The activation of inflammatory signalling pathways affects cardiomyocyte function and modes of cardiomyocyte death in sepsis. Prevention of cardiomyocyte death is an important therapeutic strategy for sepsis‑induced cardiac dysfunction. Thus, understanding the signalling pathways that activate cardiomyocyte death and cross‑regulation between death modes are key to finding therapeutic targets. The present review focused on advances in understanding of sepsis‑induced cardiomyocyte death pathways, including apoptosis, necroptosis, mitochondria‑mediated necrosis, pyroptosis, ferroptosis and autophagy. The present review summarizes the effect of inflammatory activation on cardiomyocyte death mechanisms, the diversity of regulatory mechanisms and cross‑regulation between death modes and the effect on cardiac function in sepsis to provide a theoretical basis for treatment of sepsis‑induced cardiac dysfunction.

Molecular mechanisms and functions of pyroptosis in sepsis and sepsis-associated organ dysfunction

Sepsis, a life-threatening organ dysfunction caused by a dysregulated host response to infection, is a leading cause of death in intensive care units. The development of sepsis-associated organ dysfunction (SAOD) poses a threat to the survival of patients with sepsis. Unfortunately, the pathogenesis of sepsis and SAOD is complicated, multifactorial, and has not been completely clarified. Recently, numerous studies have demonstrated that pyroptosis, which is characterized by inflammasome and caspase activation and cell membrane pore formation, is involved in sepsis. Unlike apoptosis, pyroptosis is a pro-inflammatory form of programmed cell death that participates in the regulation of immunity and inflammation. Related studies have shown that in sepsis, moderate pyroptosis promotes the clearance of pathogens, whereas the excessive activation of pyroptosis leads to host immune response disorders and SAOD. Additionally, transcription factors, non-coding RNAs, epigenetic modifications and post-translational modifications can directly or indirectly regulate pyroptosis-related molecules. Pyroptosis also interacts with autophagy, apoptosis, NETosis, and necroptosis. This review summarizes the roles and regulatory mechanisms of pyroptosis in sepsis and SAOD. As our understanding of the functions of pyroptosis improves, the development of new diagnostic biomarkers and targeted therapies associated with pyroptosis to improve clinical outcomes appears promising in the future.

LncRNA Gaplinc promotes the pyroptosis of vascular endothelial cells through SP1 binding to enhance NLRP3 transcription in atherosclerosis

Pyroptosis, characterized by activation of the Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and its downstream effector inflammatory factors, has been shown to play a crucial role in atherosclerosis development. Long noncoding RNAs (lncRNAs) are involved in the progression of pyroptosis. However, the role and mechanism of the novel lncRNA gastric adenocarcinoma associated, positive CD44 regulator (Gaplinc), in endothelial cell pyroptosis during atherosclerosis development remain unexplored. Bioinformatics was performed to evaluate dysregulated lncRNAs in atherosclerotic mice fed a high-fat diet. The effect of Gaplinc on atherosclerosis progression in vivo was assessed via Oil Red O staining and fluorescence in situ hybridization. Its function in oxidized low-density lipoprotein (ox-LDL)-induced pyroptosis of endothelial cells was determined through ectopic expression. Additionally, RNA pull-down and immunoprecipitation (RIP) assays were performed to determine Gaplinc and transcription factor SP1 interactions. Then the pyroptosis pathway proteins were analyzed via immunofluorescence and western blotting. We found that lncRNA Gaplinc was highly expressed in ox-LDL-induced endothelial cells as well as in the plaque and plasma of high-fat diet-treated ApoE^-/- mice. Gaplinc silencing significantly inhibited endothelial cell pyroptosis and atherosclerotic plaque formation. Mechanistically, Gaplinc could interact with SP1 to bind to the NLRP3 promoter and upregulate the target gene expression of NLRP3, facilitating endothelial cell pyroptosis and atherosclerotic plaque enlargement in high- fat diet-fed mice. In conclusion, our results revealed the underlying mechanism of the lncRNA Gaplinc /SP1/NLRP3 axis in endothelial cell pyroptosis, which may provide new potential targets for the treatment of atherosclerosis.

USP7-SOX9-miR-96-5p-NLRP3 network regulates myocardial injury and cardiomyocyte pyroptosis in sepsis

Sepsis is a common life-threatening pathology. This study investigated the role of transcription factor sex-determining region Y (SRY)-box 9 (SOX9) in sepsis-induced cardiomyocyte pyroptosis. A murine model of sepsis was established, followed by detection of cardiac functions and myocardial injury. HL-1 cells were induced by lipopolysaccharides (LPS). The levels of IL-18, IL-1β, TNF-α, IL-6, MDA, and SOD in myocardial tissues and HL-1 cells were determined. SOX9 ubiquitination level was measured. The binding relationships between SOX9-miR-96-5p and miR-96-5p-NLRP3 were analyzed, and the interaction between ubiquitin-specific peptidase 7 (USP7) and SOX9 was measured. SOX9 was highly expressed in septic mice and LPS-induced HL-1 cells. SOX9 silencing improved cardiac function, alleviated myocardial injury, reduced the levels of IL-1β, IL-18, cleaved caspase-1, GSDMD-N, TNF-α, IL-6, and MDA in myocardial tissues and HL-1 cells, increased the level of SOD, and alleviated cardiomyocyte pyroptosis. USP7 upregulated SOX9 expression through deubiquitination. SOX9 inhibited miR-96-5p expression and miR-96-5p targeted NLRP3. miR-96-5p silencing or USP7 overexpression reversed the inhibitory effect of SOX9 silencing on cardiomyocyte pyroptosis. Collectively, USP7 upregulated SOX9 expression through deubiquitination, and SOX9 suppressed miR-96-5p expression by binding to the miR-96-5p promoter region, thereby promoting NLRP3 expression and then exacerbating sepsis-induced myocardial injury and cardiomyocyte pyroptosis.

Yin Yang 1-induced activation of LINC01133 facilitates the progression of pancreatic cancer by sponging miR-199b-5p to upregulate myelin regulatory factor expression

Increasing evidence has reported that long non-coding RNA (lncRNA) plays a vital role in the development of pancreatic cancer (PC). However, the function and mechanism of LINC01133 in PC tumorigenesis are still unknown. Herein, we found that LINC01133 was highly expressed in PC tissues and cell lines, and LINC01133 knockdown could block the growth and metastasis of PC cells. Besides, upregulated LINC01133 in PC cells was induced by Yin Yang 1 (YY1). Furthermore, LINC01133 directly targeted miR-199b-5p and promoted cancer malignancy by suppressing miR-199b-5p. It was also discovered that myelin regulatory factor (MYRF) was targeted by miR-199b-5p and positively correlated with LINC01133 expression in PC, and LINC01133 modulated PC progression through miR-199b-5p/MYRF pathway. In conclusion, we demonstrated that YY1-mediated the upregulation of LINC0113 increased MYRF expression by sponging miR-199b-5p, resulting in the accelerated development of PC. These findings might offer a novel insight into the development of efficient therapeutics for PC patients.

Selenium protects against cadmium-induced cardiac injury by attenuating programmed cell death via PI3K/AKT/PTEN signaling

Cadmium (Cd) is an environmental pollutant that has an enormous influence on agricultural production, but selenium (Se) can alleviate its toxicity. The present study aimed to illustrate the effects of Se on Cd-induced heart injury. All 40 rabbits were randomly divided into four groups: control group, Se [0.5 mg kg^-1 ·body weight (BW)] group, Cd (1 mg kg^-1 ·BW) group, and Se + Cd group. After 30 days of feeding, morphological changes, the levels of oxidative stress and myocardial enzyme, the content of cardiac troponin T, programmed cell death (pyroptosis, autophagy and apoptosis), and PI3K/AKT/PTEN transduction capacity were observed. The results showed that Cd destroyed the physiological balance of trace elements and caused myocardial damage, increased the cardiac oxidative damage and led to programmed cell death. Coadministration of Se prominently ameliorated histological lesions and improved cardiac function of hearts in Cd-induced rabbits. Furthermore, Se exerted detoxification and oxidation resistance, maintained trace element homeostasis, and alleviated the changes of mRNA and protein levels of pyroptosis-, autophagy- and apoptosis-controlling factors and PI3K/AKT/PTEN signal molecules caused by Cd. In conclusion, Se might protect against Cd-induced pyroptosis, autophagy and apoptosis by interfering with PI3K/AKT/PTEN signaling in heart.

NRF2 Inhibits Cardiomyocyte Pyroptosis Via Regulating CTRP1 in Sepsis-Induced Myocardial Injury

ABSTRACT

C1q/tumor necrosis factor-related protein 1 (CTRP1) has been demonstrated as a crucial regulator in myocardial injury (MI). The present study aims to evaluate the mechanism of CTRP1 in sepsis-induced MI. The septic mouse model was established via cecal ligation and puncture and the in vitro cell model was established via lipopolysaccharide treatment. The mouse survival rate within 96 h was recorded. Morphologic changes of cardiomyocytes were observed and cell viability and cardiac functions were detected. CTRP1 and nuclear factor erythroid 2-related factor (Nrf2) expressions, creatine troponin-T, and creatine phosphokinase isoenzyme levels, and expressions of pyroptotic markers were determined. The binding relationship between Nrf2 and the CTRP1 promotor was predicted and verified. Rescue experiments were designed to confirm the role of CTRP1. CTRP1 was poorly expressed in septic mice. CTRP1 overexpression inhibited cardiomyocyte pyroptosis and improved cardiac functions, MI, and survival rate in septic mice. Nrf2was decreased in cecal ligation and puncture -treated mice. Nrf2 overexpression promoted CTRP1 expression via binding to the CTRP1 promotor and suppressed cardiomyocyte pyroptosis. CTRP1 downregulation abolished the inhibitory effect of Nrf2 overexpression on cardiomyocyte pyroptosis. Overall, Nrf2 promoted CTRP1 expression via binding to the CTRP1 promotor to inhibit cardiomyocyte pyroptosis, thereby alleviating MI in septic mice.

SIRT3-AMPK signaling pathway as a protective target in endothelial dysfunction of early sepsis

Extensive vascular endothelial dysfunction usually occurs in sepsis, resulting in high mortality. The purpose of this study was therefore to investigate the role of AMP-dependent protein kinase (AMPK) in the aortic endothelial dysfunction of early sepsis in mice, and the relationship between AMPK and Sirtuin3 (SIRT3). Cecal ligation and puncture (CLP) surgery was performed to establish a mouse sepsis model, and human umbilical vein endothelial cells (HUVECs) were treated with lipopolysaccharide (LPS) to mimic a sepsis model in vitro. We suppressed and increased the activities of AMPK with Dorsomorphin (CC) and Acadesine (AICAR), respectively. 3-TYP (SIRT3 inhibitor) and Honokiol (SIRT3 agonist) were used to alter SIRT3 activity. Then, the inflammatory and endothelial function parameters of the vascular tissue and survival rate were determined. In vivo, the expression of Ser1177 phosphorylation of endothelial nitric oxide synthase (p-eNOS), endothelium-dependent relaxation function, and survival decreased (P < 0.05), while NF-κB and NLRP3 pathways were activated in CLP-induced early sepsis (P < 0.05). Moreover, activation of AMPK significantly reversed the reduction of p-eNOS expression (P < 0.05), prevented endothelial dysfunction (P < 0.05), deactivated NF-κB and NLRP3 pathways (P < 0.05), and improved survival (P < 0.05) in septic mice. However, AMPK inhibition led to opposite effects (P < 0.05). In addition, changing the activity of AMPK had little effect on SIRT3 expression (P > 0.05), while the expression of p-AMPK varied with the inhibition or activation of SIRT3 (P < 0.05), which was further demonstrated using in vitro experiments. Together, the results showed that the SIRT3-AMPK signaling pathway played an important role in inhibiting vascular inflammation and endothelial dysfunction during early sepsis.

microRNA-124-3p attenuates myocardial injury in sepsis via modulating SP1/HDAC4/HIF-1α axis

Sepsis-induced cardiac dysfunction can lead to death in sepsis. In this case, we targeted to explore in detail the relative mechanism of microRNA (miR)-124-3p in sepsis-induced myocardial injury via the specific protein 1/histone deacetylase 4/hypoxia-inducing factor 1α (SP1/HDAC4/HIF-1α) axis. Septic rats were modeled by cecal ligation puncture while in vitro septic cardiomyocyte H9C2 were induced by lipopolysaccharide (LPS). miR-124-3p/SP1/HDAC4/HIF-1α expression levels in myocardial tissues of septic rats and LPS-treated H9C2 cells were measured. miR-124-3p overexpression and SP1 silencing assays were implemented on LPS-treated H9C2 cells to explore theirs actions in inflammation, oxidative stress and cell apoptosis. The interactions of miR-124-3p, SP1, and HDAC4 were testified. miR-124-3p was lowly expressed while SP1, HDAC4, and HIF-1α were highly expressed in sepsis. Upregulation of miR-124-3p ameliorated inflammation, oxidative stress, and apoptosis of LPS-treated H9C2 cells. Silencing SP1 improved LPS-induced damage to cardiomyocytes. miR-124-3p targeted SP1 and HDAC4 interacted with SP1. SP1 overexpression antagonized miR-124-3p upregulation-induced improvements in LPS-induced cardiomyocyte damage. This study illustrates that miR-124-3p improves myocardial injury in septic rats through targeted regulation of SP1 to mediate HDAC4/HIF-1α.

Yin Yang 1 (YY1)-induced long intergenic non-protein coding RNA 472 (LINC00472) aggravates sepsis-associated cardiac dysfunction via the micro-RNA-335-3p (miR-335-3p)/Monoamine oxidase A (MAOA) cascade

As a leading complication of sepsis, sepsis-induced cardiac dysfunction (SICD) contributed to the high mortality of patients with sepsis. Long non-coding RNA (LncRNA) LINC00472 has been reported to be in sepsis-induced disease. Nonetheless, its biological function and underlying molecular in SICD remain largely unknown. In this study, in vivo and in vitro SICD models were established via LPS treatment. H&E staining was employed for the evaluation of myocardial injury. ELISA assay was performed to detect cardiac Troponin I (cTnI), creatine kinase-MB (CK-MB), interleukin (IL)-1β, and tumor necrosis factor-α (TNF-α) levels. Cardiomyocyte viability and apoptosis were assessed via CCK-8 and flow cytometry assays. The transcriptional regulation of YY1 on LINC00472 was demonstrated via ChIP assay. Besides, the interaction between YY1 and LINC00472, as well as the association between miR-335-3p and LINC00472 or MAOA were verified via luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Herein, highly expressed LINC00472 was observed in both in vivo and in vitro SICD models. LINC00472 knockdown substantially attenuated LPS-induced inhibition on cardiomyocyte viability and reversed cardiomyocyte apoptosis and inflammatory response mediated by LPS treatment. YY1 induced LINC00472 upregulation, thereby promoting cardiomyocyte dysfunction induced by LPS. In addition, MAOA upregulation or miR-335-3p inhibition could partly reverse the suppressive effect on LPS-induced cardiomyocyte dysfunction mediated by LINC00472 knockdown. Based on our results, it seemed that YY1-activated LINC00472 might contribute to SICD progression via the miR-335-3p/MAOA pathway.

Long non-coding RNA muscleblind like splicing regulator 1 antisense RNA 1 (LncRNA MBNL1-AS1) promotes the progression of acute myocardial infarction by regulating the microRNA-132-3p/SRY-related high-mobility-group box 4 (SOX4) axis

Long non-coding RNA muscleblind like splicing regulator 1 antisense RNA 1 (LncRNA MBNL1-AS1) exerts vital role in various physiological processes. However, its functions in acute myocardial infarction (AMI) are not elucidated. AMI model was constructed using Wistar rats and it was found that LncRNA MBNL1-AS1 was upregulated in AMI model according to the quantitative real-time polymerase chain reaction (qRT-PCR) results. The left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP) and maximum rate of rise/fall of left ventricle pressure (±dp/dt max) were detected through hemodynamics test, which showed that knockdown of MBNL1-AS1 improved cardiac function in AMI model. Next, the myocardial infarction area was estimated by triphenyltetrazole chloride (TTC) staining, and the levels of cardiac troponin I (cTn-I) and creatine kinase-MB (CK-MB) were detected by enzyme-linked immunosorbent assay (ELISA) kit. The results revealed that silencing MBLN1-AS1 alleviated myocardial injury in AMI model. Additionally, MBNL1-AS1 knockdown inhibited apoptosis of myocardial cells and reduced the expression of apoptotic proteins. According to DIANA database and luciferase reporter assay, miR-132-3p was the direct target of MBNL1-AS1 and was negatively regulated by MBNL1-AS1. Furthermore, Targetscan database predicted that SRY-related high-mobility-group box 4 (SOX4) was the direct target of miR-132-3p and was regulated by MBNL1-AS1 through miR-132-3p. Moreover, overexpression of SOX4 partially eliminated effects of MBNL1-AS1 on myocardial cells. In conclusion, this investigation for the first time revealed that LncRNA MBNL1-AS1 was the potential target for treating AMI and expounded the underlying mechanisms of it.

Non-coding RNA-based regulation of inflammation

Inflammation is a multifactorial process and various biological mechanisms and pathways participate in its development. The presence of inflammation is involved in pathogenesis of different diseases such as diabetes mellitus, cardiovascular diseases and even, cancer. Non-coding RNAs (ncRNAs) comprise large part of transcribed genome and their critical function in physiological and pathological conditions has been confirmed. The present review focuses on miRNAs, lncRNAs and circRNAs as ncRNAs and their potential functions in inflammation regulation and resolution. Pro-inflammatory and anti-inflammatory factors are regulated by miRNAs via binding to 3'-UTR or indirectly via affecting other pathways such as SIRT1 and NF-κB. LncRNAs display a similar function and they can also affect miRNAs via sponging in regulating levels of cytokines. CircRNAs mainly affect miRNAs and reduce their expression in regulating cytokine levels. Notably, exosomal ncRNAs have shown capacity in inflammation resolution. In addition to pre-clinical studies, clinical trials have examined role of ncRNAs in inflammation-mediated disease pathogenesis and cytokine regulation. The therapeutic targeting of ncRNAs using drugs and nucleic acids have been analyzed to reduce inflammation in disease therapy. Therefore, ncRNAs can serve as diagnostic, prognostic and therapeutic targets in inflammation-related diseases in pre-clinical and clinical backgrounds.

Regulatory Role of Non-Coding RNAs on Immune Responses During Sepsis

Sepsis is resulted from a systemic inflammatory response to bacterial, viral, or fungal agents. The induced inflammatory response by these microorganisms can lead to multiple organ system failure with devastating consequences. Recent studies have shown altered expressions of several non-coding RNAs such as long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) during sepsis. These transcripts have also been found to participate in the pathogenesis of multiple organ system failure through different mechanisms. NEAT1, MALAT1, THRIL, XIST, MIAT and TUG1 are among lncRNAs that participate in the pathoetiology of sepsis-related complications. miR-21, miR-155, miR-15a-5p, miR-494-3p, miR-218, miR-122, miR-208a-5p, miR-328 and miR-218 are examples of miRNAs participating in these complications. Finally, tens of circRNAs such as circC3P1, hsa_circRNA_104484, hsa_circRNA_104670 and circVMA21 and circ-PRKCI have been found to affect pathogenesis of sepsis. In the current review, we describe the role of these three classes of noncoding RNAs in the pathoetiology of sepsis-related complications.

Melatonin Alleviates LPS-Induced Pyroptotic Cell Death in Human Stem Cell-Derived Cardiomyocytes by Activating Autophagy

Endotoxemia in sepsis remains a problem due to a lack of effective strategies. Our previous studies have demonstrated that melatonin (Mel) protects against ischemic heart injury and arteriosclerosis. However, its role in endotoxemia-exposed cardiomyocytes remains poorly understood. This study explored, for the first time, the protective effect of Mel on the pyroptosis of human stem cell-derived cardiomyocytes (hiPSC-CMs) exposed to lipopolysaccharide (LPS). Our results showed that treatment with 1 μM or 10 μM Mel for 12 h significantly improved 1 μg/ml LPS-induced hiPSC-CM injuries, as reflected by drastically decreased LDH release and increased cell viability, which was accompanied by the overt induction of autophagy. Specifically, Mel profoundly alleviated LPS-induced cell pyroptosis, as evidenced by decreased propidium iodide (PI) and active caspase-1 double-positive cell rates; suppressed the expression of NLRP3, cleaved caspase-1 (activated form of caspase-1), and GSDMD-NT (functional N-terminal fragment of GSDMD) expression; and inhibited the production of the cleaved IL-1β and cleaved IL-18 cytokines. Additionally, double-membrane autophagosomes were observed in LPS-injured hiPSC-CMs treated with 1 μM or 10 μM Mel. The hiPSC-CMs treated with LPS exhibited considerably fewer acidic vesicles (as revealed by LAMP1 staining) and autophagosomes (as revealed by LC3-II staining); however, Mel reversed this outcome in a dose-dependent manner. Furthermore, coincubation with rapamycin (an autophagy activator) or 3-MA (an autophagy inhibitor) accentuated and attenuated the antipyroptotic actions of Mel, respectively. Collectively, our findings demonstrate that Mel shields hiPSC-CMs against pyroptosis during endotoxemia by activating autophagy.

Specificity protein 1/microRNA-92b forms a feedback loop promoting the migration and invasion of head and neck squamous cell carcinoma

In this study we report a novel specificity protein 1 (SP1)/microRNA-92b (miR-92b) feedback loop regulating the migration and invasion of head and neck squamous cell carcinoma (HNSCC). Microarray and real-time Polymerase Chain Reaction (PCR) were used to detect gene expression in HNSCC tissues and cell lines. Transwell migration, invasion, wound healing and cell counting kit - 8 (CCK-8) cell assays were used to compare cell migration, invasion and proliferation abilities. Chromatin Immunoprecipitation (ChIP) assays were used to detect SP1 binding to the miR-92b promoter. Western blot was used to detect protein levels. An in vivo tumorigenesis experiment was used to evaluate the effect of SP1 knockdown on tumor growth and protein levels were evaluated by immunohistochemistry. We found that the miR-92b expression level was elevated in HNSCC primary focus tissue compared with adjacent normal tissue, and a higher level of miR-92b was related to a higher clinical stage and worse prognosis of HNSCC patients. MiR-92b and SP1 mutually promoted each expression and cooperatively facilitated the migration, invasion and proliferation of HNSCC cells. A decreased level of SP1/miR-92b resulted in a restraint of in vivo tumor growth. In conclusion, our results suggest that the SP1/miR-92b feedback loop generally promotes HNSCC invasion and metastasis, thus presenting a possible therapeutic target in the treatment of HNSCC patients.

Emerging Role of Non-Coding RNAs in Regulation of T-Lymphocyte Function

T-lymphocytes (T cells) play a major role in adaptive immunity and current immune checkpoint inhibitor-based cancer treatments. The regulation of their function is complex, and in addition to cytokines, receptors and transcription factors, several non-coding RNAs (ncRNAs) have been shown to affect differentiation and function of T cells. Among these non-coding RNAs, certain small microRNAs (miRNAs) including miR-15a/16-1, miR-125b-5p, miR-99a-5p, miR-128-3p, let-7 family, miR-210, miR-182-5p, miR-181, miR-155 and miR-10a have been well recognized. Meanwhile, IFNG-AS1, lnc-ITSN1-2, lncRNA-CD160, NEAT1, MEG3, GAS5, NKILA, lnc-EGFR and PVT1 are among long non-coding RNAs (lncRNAs) that efficiently influence the function of T cells. Recent studies have underscored the effects of a number of circular RNAs, namely circ_0001806, hsa_circ_0045272, hsa_circ_0012919, hsa_circ_0005519 and circHIPK3 in the modulation of T-cell apoptosis, differentiation and secretion of cytokines. This review summarizes the latest news and regulatory roles of these ncRNAs on the function of T cells, with widespread implications on the pathophysiology of autoimmune disorders and cancer.

Non-Coding RNAs: Master Regulators of Inflammasomes in Inflammatory Diseases

Emerging data indicates that non-coding RNAs (ncRNAs) represent more than just “junk sequences” of the genome and have been found to be involved in multiple diseases by regulating various biological process, including the activation of inflammasomes. As an important aspect of innate immunity, inflammasomes are large immune multiprotein complexes that tightly regulate the production of pro-inflammatory cytokines and mediate pyroptosis; the activation of the inflammasomes is a vital biological process in inflammatory diseases. Recent studies have emphasized the function of ncRNAs in the fine control of inflammasomes activation either by directly targeting components of the inflammasomes or by controlling the activity of various factors that control the activation of inflammasomes; consequently, ncRNAs may represent potential therapeutic targets for inflammatory diseases. Understanding the precise role of ncRNAs in controlling the activation of inflammasomes will help us to design targeted therapies for multiple inflammatory diseases. In this review, we summarize the regulatory role and therapeutic potential of ncRNAs in the activation of inflammasomes by focusing on a range of inflammatory diseases, including microbial infection, sterile inflammatory diseases, and fibrosis-related diseases. Our goal is to provide new ideas and perspectives for future research.