GSK-3β Inhibitor Induces Expression of the TLR4/MyD88/NF-κB Signaling Pathway to Protect Against Renal Ischemia-Reperfusion Injury During Rat Kidney Transplantation

Sevoflurane postconditioning ameliorates cerebral hypoxia/reoxygenation injury in zebrafish involving the Akt/GSK-3β pathway activation and the microtubule-associated protein 2 promotion

Sevoflurane postconditioning has been shown to provide neuroprotection against cerebral hypoxia-ischemia injury, but the mechanisms remain elusive. Microtubule-associated protein 2 (MAP2) is implicated in early neuronal hypoxia-ischemia injury. This study aimed to investigate whether the neuroprotective effects of sevoflurane postconditioning are related to the Akt/GSK-3β pathway and its downstream target MAP2 in zebrafish hypoxia/reoxygenation (H/R) model. Sevoflurane postconditioning or GSK-3β inhibitor TDZD-8 were used to treat H/R zebrafish. The cerebral infarction, neuronal apoptosis, and mitochondrial changes were evaluated using TTC staining, TUNEL staining, and transmission electron microscopy, respectively. The distribution of MAP2 in the brain was determined by immunofluorescence imaging. The levels of Akt, p-Akt, GSK-3β, p-GSK-3β, and MAP2 proteins were evaluated by Western blotting. The neurobehavioral recovery of zebrafish was assessed based on optokinetic response behavior. Our results indicated that sevoflurane postconditioning and TDZD-8 significantly reduced the cerebral infarction area, suppressed cell apoptosis, and improved mitochondrial integrity in zebrafish subjected to H/R. Furthermore, sevoflurane postconditioning and TDZD-8 elevated the ratios of p-Akt/Akt and p-GSK-3β/GSK-3β. However, the neuroprotective effect of sevoflurane postconditioning was effectively abolished upon suppression of MAP2 expression. In conclusion, sevoflurane postconditioning ameliorated cerebral H/R injury and facilitated the restoration of neurobehavioral function through the activation of Akt/GSK-3β pathway and promotion of MAP2 expression.

GSK3β: A ray of hope for the treatment of diabetic kidney disease

Diabetic kidney disease (DKD), a major microvascular complication of diabetes, is characterized by its complex pathogenesis, high risk of chronic renal failure, and lack of effective diagnosis and treatment methods. GSK3β (glycogen synthase kinase 3β), a highly conserved threonine/serine kinase, was found to activate glycogen synthase. As a key molecule of the glucose metabolism pathway, GSK3β participates in a variety of cellular activities and plays a pivotal role in multiple diseases. However, these effects are not only mediated by affecting glucose metabolism. This review elaborates on the role of GSK3β in DKD and its damage mechanism in different intrinsic renal cells. GSK3β is also a biomarker indicating the progression of DKD. Finally, the protective effects of GSK3β inhibitors on DKD are also discussed.

Mechanistic Implications of GSK and CREB Crosstalk in Ischemia Injury

Ischemia-reperfusion (IR) injury is a damage to an organ when the blood supply is less than the demand required for normal functioning, leading to exacerbation of cellular dysfunction and death. IR injury occurs in different organs like the kidney, liver, heart, brain, etc., and may not only involve the ischemic organ but also cause systemic damage to distant organs. Oxygen-glucose deprivation in cells causes oxidative stress, calcium overloading, inflammation, and apoptosis. CREB is an essential integrator of the body's various physiological systems, and it is widely accepted that dysfunction of CREB signaling is involved in many diseases, including ischemia-reperfusion injury. The activation of CREB can provide life to a cell and increase the cell's survival after ischemia. Hence, GSK/CREB signaling pathway can provide significant protection to cells of different organs after ischemia and emerges as a futuristic strategy for managing ischemia-reperfusion injury. Different signaling pathways such as MAPK/ERK, TLR4/MyD88, RISK, Nrf2, and NF-κB, get altered during IR injury by the modulation of GSK-3 and CREB (cyclic AMP response element (CRE)-binding protein). GSK-3 (protein kinase B) and CREB are the downstream targets for fulfilling the roles of various signaling pathways. Calcium overloading during ischemia increases the expression of calcium-calmodulin-dependent protein kinase (CaMK), which subsequently activates CREB-mediated transcription, thus promoting the survival of cells. Furthermore, this review highlights the crosstalk between GSK-3 and CREB, promoting survival and rendering the cells resistant to subsequent severe ischemia.

From Physiology to Pathology: The Role of Mitochondria in Acute Kidney Injuries and Chronic Kidney Diseases

Background

Renal diseases remain an increasing public health issue affecting millions of people. The kidney is a highly energetic organ that is rich in mitochondria. Numerous studies have demonstrated the important role of mitochondria in maintaining normal kidney function and in the pathogenesis of various renal diseases, including acute kidney injuries (AKIs) and chronic kidney diseases (CKDs).

Summary

Under physiological conditions, fine-tuning mitochondrial energy balance, mitochondrial dynamics (fission and fusion processes), mitophagy, and biogenesis maintain mitochondrial fitness. While under AKI and CKD conditions, disruption of mitochondrial energy metabolism leads to increased oxidative stress. In addition, mitochondrial dynamics shift to excessive mitochondrial fission, mitochondrial autophagy is impaired, and mitochondrial biogenesis is also compromised. These mitochondrial injuries regulate renal cellular functions either directly or indirectly. Mitochondria-targeted approaches, containing genetic (microRNAs) and pharmaceutical methods (mitochondria-targeting antioxidants, mitochondrial permeability pore inhibitors, mitochondrial fission inhibitors, and biogenesis activators), are emerging as important therapeutic strategies for AKIs and CKDs.

Key Messages

Mitochondria play a critical role in the pathogenesis of AKIs and CKDs. This review provides an updated overview of mitochondrial homeostasis under physiological conditions and the involvement of mitochondrial dysfunction in renal diseases. Finally, we summarize the current status of mitochondria-targeted strategies in attenuating renal diseases.

Glycogen synthase kinase-3β mediates toll-like receptors 4/nuclear factor kappa-B-activated cerebral ischemia-reperfusion injury through regulation of fat mass and obesity-associated protein

BACKGROUND

Glycogen synthase kinase-3β (GSK3β), fat mass and obesity-associated protein (FTO), and toll-like receptors 4 (TLR4) take on critical significance in different biological processes, whereas their interactions remain unclear. The objective was the investigation of the interaction effect in cerebral ischemia-reperfusion (I/R) injury.

METHODS

The function of the cerebral cortex in the mouse middle cerebral artery occlusion (MCAO) model (each group n = 6) and P12 cells oxygen-glucose deprivation/reoxygenation (OGD/R) model was analyzed using short hairpin GSK3β lentivirus and overexpression of FTO lentivirus (in vitro), TLR4 inhibitor (TAK242), and LiCl to regulate GSK3β, FTO, TLR4 expression, and GSK3β activity, respectively.

RESULTS

After GSK3β knockdown in the OGD/R model of PC12 cells, the levels of TLR4 and p-p65 were lower than in the control, and the level of FTO was higher than in the control. Knockdown GSK3β reversed the OGD/R-induced nuclear factor kappa-B transfer to the intranuclear nuclei. As indicated by the result, TLR4 expression was down-regulated by overexpressed FTO, and TLR4 expression was up-regulated notably after inhibition of FTO with the use of R-2HG. After the inhibition of the activity of GSK3β in vivo, the reduction of FTO in mice suffering from MCAO was reversed.

CONCLUSIONS

Our research shows that GSK3β/FTO/TLR4 pathway contributes to cerebral I/R injury.

Bioinformatic identification of hub genes Myd88 and Ccl3 and TWS-119 as a potential agent for the treatment of massive cerebral infarction

Background

Massive cerebral infarction (MCI) causes severe neurological deficits, coma and can even result in death. Here, we identified hub genes and pathways after MCI by analyzing microarray data from a murine model of ischemic stroke and identified potential therapeutic agents for the treatment of MCI.

Methods

Microarray expression profiling was performed using the GSE28731 and GSE32529 datasets from the Gene Expression Omnibus (GEO) database. Data from a sham group (n = 6 mice) and a middle cerebral artery occlusion (MCAO) group (n = 7 mice) were extracted to identify common differentially expressed genes (DEGs). After identifying gene interactions, we generated a protein-protein interaction (PPI) network with Cytoscape software. Then, the MCODE plug-in in Cytoscape was used to determine key sub-modules according to MCODE scores. Enrichment analyses were then conducted on DEGs in the key sub-modules to evaluate their biological functions. Furthermore, hub genes were identified by generating the intersections of several algorithms in the cytohubba plug-in; these genes were then verified in other datasets. Finally, we used Connectivity MAP (CMap) to identify potential agents for MCI therapy.

Results

A total of 215 common DEGs were identified and a PPI network was generated with 154 nodes and 947 edges. The most significant key sub-module had 24 nodes and 221 edges. Gene ontology (GO) analysis showed that the DEGs in this sub-module showed enrichment in inflammatory response, extracellular space and cytokine activity in terms of biological process, cellular component and molecular function, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that TNF signaling was the most enriched pathway. Myd88 and Ccl3 were identified as hub genes and TWS-119 was identified as the most potential therapeutic agent by CMap.

Conclusions

Bioinformatic analysis identified two hub genes (Myd88 and Ccl3) for ischemic injury. Further analysis identified TWS-119 as the best potential candidate for MCI therapy and that this target may be associated with TLR/MyD88 signaling.

Selenomethionine attenuates ochratoxin A-induced small intestinal injury in rabbits by activating the Nrf2 pathway and inhibiting NF-κB activation

The aim of this study was to investigate whether selenomethionine (SeMet) could attenuate intestinal injury in rabbits induced by ochratoxin A (OTA). Sixty 35-day-old IRA rabbits with similar weights were randomly assigned to the control group, OTA group (0.2 mg OTA/kg b.w), OTA+ 0.2 mg/kg Se (0.2 mg OTA/kg b.w + 0.2 mg SeMet/kg feed), OTA+ 0.4 mg/kg Se (0.2 mg OTA/kg b.w + 0.4 mg SeMet/kg feed) and OTA+ 0.6 mg/kg Se (0.2 mg OTA/kg b.w + 0.6 mg SeMet/kg feed). The rabbits were examined after oral administration of different doses of SeMet for 21 days and were intragastrically administered OTA for 7 consecutive days. The results showed that pretreatment with different doses of SeMet protected against the changes in serum biochemical indicators and the decline in production performance caused by OTA exposure. In addition, the activities of SOD, GSH-PX and T-AOC were significantly increased, and the levels of MDA and ROS were decreased after SeMet pretreatment; thus, oxidative damage in rabbit jejunum tissue due to OTA exposure was inhibited. SeMet stimulates Nrf2 and inhibits the NF-κB signalling pathway; the anti-inflammatory response and antioxidative stress in rabbits were improved, and the intestinal barrier damage caused by OTA exposure was improved. In summary, SeMet alleviates OTA-induced intestinal toxicity in rabbits by activating the Nrf2 pathway and inhibiting NF-κB activation. Moreover, 0.4 mg/kg SeMet induced the most significant improvement.

Potential drugs for the treatment of Alzheimer's disease

It is well known that amyloid precursor protein (APP), the enzyme β-secretase 1 (BACE1), cyclooxygenase 2 (COX-2), nicastrin (NCT), and hyperphosphorylated tau protein (p-tau) are closely related to the development of Alzheimer's disease (AD). In addition, recent evidence shows that neuroinflammation also contributes to the pathogenesis of AD. Although the mechanism is not clearly known, such inflammation could alter the activity of the aforementioned molecules. Therefore, the use of anti-inflammatory agents could slow the progression of the disease. Nimesulide, resveratrol, and citalopram are three anti-inflammatory agents that could contribute to a decrease in neuroinflammation and consequently to a decrease in the overexpression of APP, BACE1, COX-2, NCT, and p-Tau, as they possess anti-inflammatory effects that could regulate the expression of APP, BACE1, COX-2, NCT, and p-Tau of potent pro-inflammatory markers indirectly involved in the expression of APP, BACE1, NCT, COX-2, and p-Tau; therefore, their use could be beneficial as preventive treatment as well as in the early stages of AD.

Indoloquinazoline alkaloids with cardiomyocyte protective activity against cold ischemic injury from Aspergillus clavatonanicus

The arthropod-associated fungi have been demonstrated to be a remarkable producer of structurally captivating and bioactive secondary metabolites for drug discovery. In this study, eleven new indoloquinazoline alkaloids, namely aspergilloids A-K (1-11), along with five known congeners (12-16), were obtained from fungus Aspergillus clavatonanicus, which was isolated from the gut of a centipede collected in our Tongji campus. All these compounds were rarely defined by a 6/5/5 indolone ring system in conjugation with a five-membered spiral ring (1-5 and 10-16) or an opening five-membered spiral ring (6-9). Their structures were elucidated by widespread spectroscopic analyses, mainly including HRESIMS and 1D and 2D NMR data, single-crystal X-ray diffraction, and electronic circular dichroism (ECD) data analyses. The cardiomyocyte protective activity assay revealed that compounds 1, 2, 5, 12-14, and 16 ameliorated cold ischemic injury at 48 h post cold ischemia (CI), and compounds 1, 5, and 14 prevented cold ischemia induced Ser9 dephosphorylation of GSK3β at 12 h post CI. Our current study highlights indoloquinazoline alkaloids as the first class of natural cardiomyocyte protective agents against cold ischemic injury, which furnishes promising lead molecules for the development of new cardioprotectants in heart transplantation medicine.

Immune response associated with ischemia and reperfusion injury during organ transplantation

Background

Ischemia and reperfusion injury (IRI) is an ineluctable immune-related pathophysiological process during organ transplantation, which not only causes a shortage of donor organs, but also has long-term and short-term negative consequences on patients. Severe IRI-induced cell death leads to the release of endogenous substances, which bind specifically to receptors on immune cells to initiate an immune response. Although innate and adaptive immunity have been discovered to play essential roles in IRI in the context of organ transplantation, the pathway and precise involvement of the immune response at various stages has not yet to be elucidated.

Methods

We combined “IRI” and “organ transplantation” with keywords, respectively such as immune cells, danger signal molecules, macrophages, neutrophils, natural killer cells, complement cascade, T cells or B cells in PubMed and the Web of Science to search for relevant literatures.

Conclusion

Comprehension of the immune mechanisms involved in organ transplantation is promising for the treatment of IRI, this review summarizes the similarities and differences in both innate and adaptive immunity and advancements in the immune response associated with IRI during diverse organ transplantation.

Sporoderm-broken spores of Ganoderma lucidum alleviates liver injury induced by DBP and BaP co-exposure in rat

Dibutyl phthalate (DBP) and Benzo(a)pyrene (BaP) are ubiquitous contaminants in environment and foodstuffs, which increase the chance of their combined exposure to humans in daily life. However, the combined effects of DBP and BaP on liver and the underlying mechanisms are still unclear. In this study, we explored the combined effects of DBP and BaP on liver and the potential mechanisms in a rat model. We found that DBP and BaP co-exposure activated the MyD88/NF-κB pathway through increasing TLR4 acetylation (TLR4ac) level, leading to the imbalance of pro-inflammatory factors (CXCL-13, IL-6 and TNF-α) and anti-inflammatory factors (IL-10), ultimately resulting in liver tissue damage and functional changes. Sporoderm-broken spores of Ganoderma lucidum (SSGL) had strong alleviating effects on liver injury induced by DBP and BaP co-exposure. Our study found that SSGL suppressed TLR4ac-regulated MyD88/NF-κB signaling to reduce the release of pro-inflammatory factors, and promote the secretion of IL-10, thus alleviating liver injury caused by DBP and BaP co-exposure. In conclusion, SSGL contributed to liver protection against DBP and BaP-induced liver injury in rats via suppressing the TLR4ac-regulated MyD88/NF-κB signaling.

Protective Effect of Melatonin for Renal Ischemia-Reperfusion Injury: A Systematic Review and Meta-Analysis

Background: Renal ischemia-reperfusion (I/R) injury is one of the major causes related to acute kidney damage. Melatonin has been shown as a powerful antioxidant, with many animal experiments have been designed to evaluate the therapeutic effect of it to renal I/R injury.

Objectives: This systematic review aimed to assess the therapeutic effect of melatonin for renal I/R injury in animal models.

Methods and Results: The PubMed, Web of Science, Embase, and Science Direct were searched for animal experiments applying melatonin to treat renal I/R injury to February 2021. Thirty-one studies were included. The pooled analysis showed a greater reduction of blood urea nitrogen (BUN) (21 studies, weighted mean difference (WMD) = −30.00 [−42.09 to −17.91], p < 0.00001), and serum creatinine (SCr) (20 studies, WMD = −0.91 [−1.17 to −0.66], p < 0.00001) treated with melatonin. Subgroup analysis suggested that multiple administration could reduce the BUN compared with control. Malondialdehyde and myeloperoxidase were significantly reduced, meanwhile, melatonin significantly improved the activity of glutathione, as well as superoxide dismutase. The possible mechanism for melatonin to treat renal I/R injury is inhibiting endoplasmic reticulum stress, apoptosis, inflammation, autophagy, and fibrillation in AKI to chronic kidney disease.

Conclusions: From the available data of small animal studies, this systematic review demonstrated that melatonin could improve renal function and antioxidative effects to cure renal I/R injury through, then multiple administration of melatonin might be more appropriate. Nonetheless, extensive basic experiments are need to study the mechanism of melatonin, then well-designed randomized controlled trials to explore the protective effect of melatonin.

Skullcapflavone II protects neuronal damage in cerebral ischemic rats via inhibiting NF-ĸB and promoting angiogenesis

BACKGROUND

Cerebral ischemia (CI) is considered as a main cause of cerebral stroke (CS) and poses significant risk to the mankind across the world. In the present study, we intended to investigate the protective effect of Skullcapflavone II (SCP) a flavonoid isolated from S. baicalensis on cerebral ischemia/reperfusion (I/R) injury.

METHODS

The middle cerebral artery occlusion (MCAO) and reperfusion was used to create ischemic stroke rat model. The rats were treated with (5, 10, and 15 mg/kg) SCP and after the end of the experiment the rats were sacrificed and various biochemical parameters were assed to determine the pharmacological action of SCP.

RESULTS

SCP dramatically decreases cerebral edema, infarct volume, and improves neurological manifestation as confirmed by reduced neurological deficit. SCP also improves the survivability of neurons as evidenced by H and E and Nissl staining. The level of oxidative stress in the cerebral cortex of the rats was found reduced after treatment with SCP, as confirmed by increase in GSH and SOD activity with reduction in MDA content. In addition, SCP attenuated inflammation via reducing the level of TNF-α, IL-1β and IL-6 in brain tissues of rats. SCP increases the expression of Bcl2, cleaved caspase-3 and -9, while decreasing Bax, and NF-ĸB/TLR4. It causes induction of angiogenesis as suggested by increased expression of VEGF, Ang-1 and Tie-2 in cerebral cortex of rat.

CONCLUSIONS

Our data determined that SCP may provide protective effect on the I/R-induced cerebral ischemia.

The potential therapeutic effects of Trifolium alexandrinum extract, hesperetin and quercetin against diabetic nephropathy via attenuation of oxidative stress, inflammation, GSK-3β and apoptosis in male rats

Diabetic nephropathy (DN) is one of the manifestations of systemic microangiopathy in diabetes. Trifolium alexandrinum extract (TAE) contains biologically active phenolic compounds such as hesperetin (HES) and quercetin, possess various pharmacological properties, including anti-inflammatory, and anti-oxidative potentials. The present study aimed to assess the therapeutic effects and mechanisms underlying the anti-diabetic, antioxidant, and anti-inflammatory effects of HES and quercetin extracted from TAE, and TAE in STZ-induced DN. Male albino rats (170 ± 10 g) were divided into group (1); control rats and groups (2-5); diabetic/HFD were intraperitoneal (i.p.) injected with STZ (35 mg/kg), diabetic rats were randomly classified into STZ, STZ + HES (40 mg/kg), STZ + quercetin (50 mg/kg), and STZ + TAE (200 mg/kg) groups. After 5 weeks, blood and kidney samples were collected for further biochemical, western blotting and histopathological studies. Serum renal functions, renal oxidative status biomarkers and proinflammatory cytokines were determined. The results revealed that there were significant increases in urea, BUN, creatinine, ALP, total protein, albumin, and globulin with a significant decrease in Na⁺ and K⁺ levels, as well as significant elevation in TBARS, TGF-β, TNF-α, IL-6 and the expression levels of GSK-3β, as well as significant decline in TAC, GSH and CAT levels in STZ-treated group compared to the control rats. The previous deleterious alterations were significantly ameliorated after the treatment of diabetic rats with HES, quercetin and TAE. In conclusion, our data demonstrated that HES, quercetin and TAE could be used as potent therapeutic agents to counter DN through antioxidant, anti-inflammatory, and antidiabetic effects.

Celastrol-based nanomedicine promotes corneal allograft survival

Effectively promoting corneal allograft survival remains a challenge in corneal transplantation. The emerging therapeutic agents with high pharmacological activities and their appropriate administration routes provide attractive solutions. In the present study, a celastrol-loaded positive nanomedicine (CPNM) was developed to enhance corneal penetration and to promote corneal allograft survival. The in vitro, in vivo and ex vivo results demonstrated the good performance of CPNM prolonging the retention time on ocular surface and opening the tight junction in cornea, which resulted in enhanced corneal permeability of celastrol. Both in vitro and in vivo results demonstrated that celastrol inhibited the recruitment of M1 macrophage and the expression of TLR4 in corneal allografts through the TLR4/MyD88/NF-κB pathway, thereby significantly decreasing secretion of multiple pro-inflammatory cytokines to promote corneal allograft survival. This is the first celastrol-based topical instillation against corneal allograft rejection to provide treatment more potent than conventional eye drops for ocular anterior segment diseases.

Recent Approaches to Targeting Canonical NFκB Signaling in the Early Inflammatory Response to Renal IRI

Ischemia reperfusion injury (IRI) is the most common cause of in-hospital AKI and is associated with increased morbidity and mortality. IRI is associated with an early phase of inflammation primarily regulated by the canonical NFκB signaling pathway. Despite recent advances in our understanding of the pathogenesis of IRI, few therapeutic strategies have emerged. The purpose of this manuscript is to review interventions targeting NFκB after IRI.

Inhibition of Glycogen Synthase Kinase 3β Alleviates Chronic Renal Allograft Dysfunction in Rats

BACKGROUND

Chronic renal allograft dysfunction (CRAD) is a major condition that impedes the long-term survival of renal allografts. However, the mechanism of CRAD is obscure, and the effective strategies for controlling the progression of CRAD are lacking. The present study used a CRAD rat model to assess the effect of glycogen synthase kinase 3β (GSK-3β) inhibition on the development of CRAD.

METHODS

A classical F334-to-LEW orthotopic renal transplantation was performed on the CRAD group. The treatment group was treated with the GSK-3β inhibitor 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione for 12 consecutive weeks following renal transplantation. The study included uninephrectomized F344 and Lewis rats as control subjects. Twelve weeks post surgery, the rats were retrieved for analysis of renal function, urine protein levels, histological, immunohistochemical, and molecular biological parameters.

RESULTS

Administration of 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione inactivated GSK-3β and thereby improved renal function, attenuated proteinuria, and reduced renal tissue damage in CRAD rats. Besides, inactivation of GSK-3β inhibited nuclear factor-κB activation, macrophage infiltration, and expression of multiple proinflammatory cytokines/chemokines. Inhibition of GSK-3β also decreased the levels of malondialdehyde, increased superoxide dismutase levels, upregulated the expression of heme oxygenase-1 and NAD(P)H quinone oxidoreductase-1, and enhanced nuclear translocation of nuclear factor erythroid 2-related factor 2 in the kidneys of CRAD rats.

CONCLUSIONS

Inhibition of GSK-3β attenuates the development of CRAD by inhibiting inflammation and oxidant stress. Thus, GSK-3β inhibition may represent a potential therapeutic strategy for the prevention and treatment of CRAD.

MiR-155/GSK-3β mediates anti-inflammatory effect of Chikusetsusaponin IVa by inhibiting NF-κB signaling pathway in LPS-induced RAW264.7 cell

It has been demonstrated that Chikusetsusaponin IVa (CsIVa) possesses abundant biological activities. Herein, using LPS to establish acute inflammation model of mouse liver and cell line inflammation model, we investigated whether miR-155/GSK-3β regulated NF-κB signaling pathway, and CsIVa exerted anti-inflammatory effects by regulating miR-155/GSK-3β signaling pathway. Our results showed that LPS induced high expression of miR-155 and miR-155 promoted macrophage activation through GSK-3β. In addition, CsIVa inhibited inflammatory responses in LPS-induced mouse liver and RAW264.7 cells. Furthermore, we demonstrated that CsIVa improved the inflammatory response in LPS-induced RAW264.7 cells by inhibiting miR-155, increasing GSK-3β expression, and inhibiting NF-κB signaling pathway. In conclusion, our study reveals that CsIVa suppresses LPS-triggered immune response by miR-155/GSK-3β-NF-κB signaling pathway.

Circular RNA ANKRD36 attends to lipopolysaccharide-aroused MRC-5 cell injury via regulating microRNA-31-3p

BACKGROUND

Some circular RNAs (circRNAs) are reported to attend to the pathogenesis of pneumonia. This study tested the impact of circRNA ankyrin repeat domain 36 (circANKRD36) on human embryonic lung fibroblast MRC-5 cell injury irritated by lipopolysaccharide (LPS).

METHODS

After LPS irritation, viability, apoptosis, ROS, protein, and cytokines, along with circANKRD36 were tested by CCK-8, Annexin V-FITC, DCFH-DA, and ELISA or Western blot. si-circANKRD36 and microRNA-31-3p/5p (miR-31-3p/5p) inhibitor were applied to silence circANKRD36 and miR-31-3p/5p. miR-31-3p/5p mimic was utilized to upregulate miR-31-3p/5p. RT-qPCR was used to detect miRNAs. The relationship between miRNAs and MyD88 or IL-34 was analyzed by luciferase activity reporter assay.

RESULTS

LPS aroused a decrease in viability, increases in apoptosis, ROS, and IL-6, IL-8, and TNF-α, along with circANKRD36, and activation of NF-κB pathway. Silencing circANKRD36 weakened the above-mentioned influences of LPS. Moreover, silencing circANKRD36 hoisted miR-31-3p expression. Silencing miR-31-3p mitigated the impacts of circANKRD36 silence on LPS-irritated MRC-5 cells. Besides, MyD88 was a downstream target of miR-31-3p, and 3'UTR of IL-34 mRNA was targeted by miR-31-5p. LPS induced the accumulation of MyD88. Silencing MyD88 was constructive to maintain cell viability, retard apoptosis and inhibit adverse oxidation and inflammation.

CONCLUSION

This research verified that silencing circANKRD36 could weaken LPS-irritated MRC-5 cell injury via regulating miR-31/MyD88-mediated repression of NF-κB pathway.