β-Arrestin-2 attenuates hepatic ischemia-reperfusion injury by activating PI3K/Akt signaling

Exploring the potential mechanism of Radix Bupleuri in the treatment of sepsis: a study based on network pharmacology and molecular docking

AIM

To explore, using network pharmacology and RNA-seq technologies, potential active targets and mechanisms underpinning Radix Bupleuri's effectiveness during sepsis treatment.

METHODS

Following the Sepsis-3.0 criteria, the research cohort, comprising 23 sepsis patients and 10 healthy participants, was obtained from public databases. Peripheral blood samples were collected and subjected to RNA-seq analysis. Active ingredients and potential targets of Radix Bupleuri were identified using the Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine 2.0 (BATMAN-TCM 2.0) database and TCMSP database. Subsequently, protein-protein interaction (PPI) network construction, Gene Ontology (GO) analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted to explore cross-targets between disease and drugs. Survival analysis of key targets was performed using the GSE65682 dataset, and single-cell RNA-seq was employed for cellular localization analysis of key genes. Finally, molecular docking and Molecular dynamics simulation of the core target was conducted.

RESULTS

Differential expression analysis revealed 4253 genes associated with sepsis. Seventy-six active components and 1030 potential targets of Radix Bupleuri were identified. PPI, GO, and pathway enrichment analyses indicated involvement in the regulation of transmembrane transport, monatomic ion transport, and MAPK signaling. Survival curve analysis identified PIK3CD, ARRB2, SUCLG1, and SPI1 as key targets associated with lower mortality in the high expression group, while higher mortality was observed in the high PNP and FURIN expression groups. Single-cell RNA sequencing unveiled the cellular localization of PIK3CD, PNP, SPI1, and FURIN within macrophages, while ARRB2 and SUCLG1 exhibited localization in both macrophages and T-cells. Subsequent molecular docking and Molecular dynamics simulation indicated a potential binding interaction for Carvone-PIK3CD, Encecalin-ARRB2, Lauric Acid-SUCLG1, Pulegone-FURIN, Nootkatone-SPI1, and Saikogenin F-PNP.

CONCLUSION

Radix Bupleuri could modulate immune function by affecting PIK3CD, ARRB2, SUCLG1, FURIN, SPI1, and PNP, thereby potentially improving the prognosis of sepsis.

Sevoflurane enhances autophagy via Rac1 to attenuate lung ischaemia‒reperfusion injury

Sevoflurane can attenuate lung ischaemia‒reperfusion injury (LIRI). However, the protective mechanism is unclear. In this study, we developed a LIRI model in vivo that animals (SD, n = 15) were subjected to the administration of 2.2 % sevoflurane 30 min before the onset of left pulmonary artery clamping for 45 min, which was then followed by 60 min of reperfusion treatment. Then, transcriptome sequencing was used to analyse lung tissues. Autophagy inhibition (3-MA) and Rac1-overexpression transfection plasmids were used in BEAS-2B cells, and BEAS-2B cells were subjected to hypoxia reoxygenation (H/R) and sevoflurane treatment. In both animal tissue and cells, inflammatory cytokines and apoptotic and autophagy molecules were measured by quantitative real-time PCR, western blotting and immunostaining. As a result, decreased arterial partial oxygen and damage to the histological structure of lung tissues were observed in LIRI model rats, and these effects were reversed by sevoflurane treatment. Activation of inflammation (elevated IL-1β, IL-6, and TNF-α) and apoptosis (elevated cleaved caspase3/caspase3 and Bax, degraded expression of Bcl2) and inhibition of autophagy (elevated P62, degraded expression of Beclin1 and LC3-II/LC3I) in the model group were ameliorated by sevoflurane. Transcriptome sequencing indicated that the PI3K/Akt pathway regulated by Rac1 plays an important role in LIRI. Furthermore, overexpression of Rac1 in a cell line inhibited the protective effect of sevoflurane in LIRI. Autophagy inhibition (3-MA) also prevented the protective effect of sevoflurane on inflammation and apoptosis. As shown in the present study, sevoflurane enhances autophagy via Rac1/PI3K/AKT signalling to attenuate lung ischaemia‒reperfusion injury.

The Coming Age of Antisense Oligos for the Treatment of Hepatic Ischemia/Reperfusion (IRI) and Other Liver Disorders: Role of Oxidative Stress and Potential Antioxidant Effect

Imbalances in the redox state of the liver arise during metabolic processes, inflammatory injuries, and proliferative liver disorders. Acute exposure to intracellular reactive oxygen species (ROS) results from high levels of oxidative stress (OxS) that occur in response to hepatic ischemia/reperfusion injury (IRI) and metabolic diseases of the liver. Antisense oligonucleotides (ASOs) are an emerging class of gene expression modulators that target RNA molecules by Watson-Crick binding specificity, leading to RNA degradation, splicing modulation, and/or translation interference. Here, we review ASO inhibitor/activator strategies to modulate transcription and translation that control the expression of enzymes, transcription factors, and intracellular sensors of DNA damage. Several small-interfering RNA (siRNA) drugs with N-acetyl galactosamine moieties for the liver have recently been approved. Preclinical studies using short-activating RNAs (saRNAs), phosphorodiamidate morpholino oligomers (PMOs), and locked nucleic acids (LNAs) are at the forefront of proof-in-concept therapeutics. Future research targeting intracellular OxS-related pathways in the liver may help realize the promise of precision medicine, revolutionizing the customary approach to caring for and treating individuals afflicted with liver-specific conditions.

Hippo (YAP)-autophagy axis protects against hepatic ischemia-reperfusion injury through JNK signaling

BACKGROUND

Hepatic ischemia-reperfusion injury (HIRI) remains a common complication during liver transplantation (LT) in patients. As a key downstream effector of the Hippo pathway, Yes-associated protein (YAP) has been reported to be involved in various physiological and pathological processes. However, it remains elusive whether and how YAP may control autophagy activation during ischemia-reperfusion.

METHODS

Human liver tissues from patients who had undergone LT were obtained to evaluate the correlation between YAP and autophagy activation. Both an in vitro hepatocyte cell line and in vivo liver-specific YAP knockdown mice were used to establish the hepatic ischemia-reperfusion models to determine the role of YAP in the activation of autophagy and the mechanism of regulation.

RESULTS

Autophagy was activated in the post-perfusion liver grafts during LT in patients, and the expression of YAP positively correlated with the autophagic level of hepatocytes. Liver-specific knockdown of YAP inhibited hepatocytes autophagy upon hypoxia-reoxygenation and HIRI ( P <0.05). YAP deficiency aggravated HIRI by promoting the apoptosis of hepatocytes both in the in vitro and in vivo models ( P <0.05). Attenuated HIRI by overexpression of YAP was diminished after the inhibition of autophagy with 3-methyladenine. In addition, inhibiting autophagy activation by YAP knockdown exacerbated mitochondrial damage through increasing reactive oxygen species ( P <0.05). Moreover, the regulation of autophagy by YAP during HIRI was mediated by AP1 (c-Jun) N-terminal kinase (JNK) signaling through binding to the transcriptional enhanced associate domain (TEAD).

CONCLUSIONS

YAP protects against HIRI by inducing autophagy via JNK signaling that suppresses the apoptosis of hepatocytes. Targeting Hippo (YAP)-JNK-autophagy axis may provide a novel strategy for the prevention and treatment of HIRI.

Puerarin protects the fatty liver from ischemia-reperfusion injury by regulating the PI3K/AKT signaling pathway

The incidence of non-alcoholic fatty liver (NAFLD) remains high, and many NAFLD patients suffer from severe ischemia-reperfusion injury (IRI). Currently, no practical approach can be used to treat IRI. Puerarin plays a vital role in treating multiple diseases, such as NAFLD, stroke, diabetes, and high blood pressure. However, its role in the IRI of the fatty liver is still unclear. We aimed to explore whether puerarin could protect the fatty liver from IRI. C57BL/6J mice were fed with a high-fat diet (HFD) followed by ischemia reperfusion injury. We showed that hepatic IRI was more severe in the fatty liver compared with the normal liver, and puerarin could significantly protect the fatty liver against IRI and alleviate oxidative stress. The PI3K-AKT signaling pathway was activated during IRI, while liver steatosis decreased the level of activation. Puerarin significantly protected the fatty liver from IRI by reactivating the PI3K-AKT signaling pathway. However, LY294002, a PI3K-AKT inhibitor, attenuated the protective effect of puerarin. In conclusion, puerarin could significantly protect the fatty liver against IRI by activating the PI3K-AKT signaling pathway.

Targeting PI3K/p-Akt/eNOS, Nrf2/HO-1, and NF-κB/p53 signaling pathways by angiotensin 1-7 protects against liver injury induced by ischemia-reperfusion in rats

The liver is an important organ, and hepatic ischemia-reperfusion (IR) injury is a frequent pathophysiological process that can cause significant morbidity and mortality. Thus, our study aimed to investigate the effect of targeting PI3K/p-Akt/eNOS (phosphoinositide 3-kinase/phospho-protein kinase B/endothelial nitric oxide synthase), Nrf2/HO-1 (nuclear factor-erythroid 2-related factor-2/heme oxygenase-1), and NF-κB/p53 (nuclear factor-κB/tumor protein 53) signaling pathways by using angiotensin (1-7) [ang-(1-7)] against hepatic injury induced by IR. Thirty-two male rats were included in sham group, ang-(1-7)-treated group, hepatic IR group, and hepatic IR group treated with ang-(1-7). The levels of hepatic ang-(1-7), angiotensin II (Ang II), angiotensin-converting enzyme 2 (ACE2), HO-1, malondialdehyde (MDA), PI3K, and p-Akt were assessed. The expressions of eNOS and B-cell leukemia/lymphoma-2 (BCL-2) in the liver were determined. Histological assessment and immunohistochemical expression of NF-κB, p53, and Nrf2 were carried out. The levels of reduced glutathione (GSH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in serum were estimated. Results showed that administration of ang-(1-7) to hepatic IR rats led to significant amelioration of hepatic damage through a histological evaluation that was associated with significant upregulation of the expressions of PI3K/p-Akt/eNOS and Nrf2/HO-1 with downregulation of NF-κB/p53 signaling pathways. In conclusion, PI3K/p-Akt/eNOS and Nrf2/HO-1 signaling pathways are involved in the protective effects of ang-(1-7) against hepatic damage induced by IR. Therefore, ang-(1-7) can be used to prevent hepatic IR, which occurs in certain conditions such as liver transplantation, hemorrhagic shock, and severe infection.

Recombinant human brain natriuretic peptide attenuates ischemic brain injury in mice by inhibiting oxidative stress and cell apoptosis via activation of PI3K/AKT/Nrf2/HO-1 pathway

Ischemic stroke followed by cerebral artery occlusion is a main cause of chronic disability worldwide. Recombinant human brain natriuretic peptide (rhBNP) has been reported to alleviate sepsis-induced cognitive dysfunction and brain I/R injury. However, the function and molecular mechanisms of rhBNP in ischemic brain injury have not been clarified. For establishment of an animal model of ischemic brain injury, C57BL/6 mice were treated with middle cerebral artery occlusion (MCAO) surgery for 1 h and reperfusion for 24 h. After subcutaneous injection of rhBNP into model mice, neurologic deficits were assessed by evaluating behavior of mice according to Longa scoring system, and TTC staining was utilized to determine the brain infarct size of mice. The levels of oxidative stress markers, superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and malondialdehyde (MDA), were detected in hippocampal tissues of mice by corresponding kits. Cell apoptosis in hippocampus tissues was examined by TUNEL staining. Protein levels of antioxidant enzymes (HO-1 and NQO1) in cerebral cortex, apoptotic markers (Bax, Bcl-2, and cleaved caspase), and PI3K/AKT pathway-associated factors in hippocampus were tested by western blot analysis. The results revealed that injection of rhBNP decreased neurologic deficit scores, the percent of brain water content, and infarct volume. Additionally, rhBNP downregulated MDA level, upregulated the levels of SOD, CAT, and GSH in hippocampus of mice, and increased protein levels of HO-1 and NQO1 in the cortex. Cell apoptosis in hippocampus tissues of model mice was inhibited by rhBNP which was shown as the reduced TUNEL-positive cells, the decreased Bax, cleaved caspase-3, and cleaved caspase-9 protein levels, and the enhanced Bcl-2 protein level. In addition, rhBNP treatment activated the PI3K/AKT signaling pathway and upregulated the protein levels of HO-1 and NRF2. Overall, rhBNP activates the PI3K/AKT/HO-1/NRF2 pathway to attenuate ischemic brain injury in mice after MCAO by suppression of cell apoptosis and oxidative stress.

Hepatic β-arrestins: potential roles in liver health and disease

Β-arrestins are intracellular scaffolding proteins that have multifaceted roles in different types of disorders. In this review article, we gave a summary about the discovery, characterization and classification of these proteins and their intracellular functions. Moreover, this review article focused on the hepatic expression of β-arrestins and their hepatocellular distribution and function in each liver cell type. Also, we showed that β-arrestins are key regulators of distinct types of hepatic disorders. On the other hand, we addressed some important points that have never been studied before regarding the role of β-arrestins in certain types of hepatic disorders which needs more research efforts to cover.

PPARγ Regulates Macrophage Polarization by Inhibiting the JAK/STAT Pathway and Attenuates Myocardial Ischemia/Reperfusion Injury In Vivo

This study aimed to investigate the role of PPARγ and underlying mechanisms in myocardial ischemia/reperfusion injury (IRI). IRI was surgically induced in mice and neonatal rat cardiomyocytes (NRCM) were exposed to oxygen-glucose deprivation and reoxygenation (OGD/R). Quantitative genetic analysis and western blotting were performed to assess mRNA and protein levels, respectively, of PPARγ, as well as of different inflammatory, fibrosis, and apoptosis markers in cells and tissues. PPARγ was overexpressed in the heart of mice and NRCMs by viral transfection. Apoptosis and fibrosis were detected by TUNEL and Masson's trichrome staining, respectively. Enzyme-linked immunosorbent assay was performed to detect M1 and M2 macrophage-related inflammatory factors present in mouse sera. PPARγ overexpression significantly inhibited OGD/R- and IRI-induced cardiomyocyte apoptosis and fibrosis in vitro and in vivo. Moreover, PPARγ overexpression inhibited IRI-induced secretion of M1-related proinflammatory factors, whereas it supported the secretion of M2-related anti-inflammatory factors. Notably, these events were found to be mediated by the JAK/STAT pathway. In conclusion, PPARγ regulates macrophage polarization upon IRI via the JAK/STAT pathway, which will in turn prevent myocardial apoptosis and fibrosis. Hence, PPARγ may represent a valuable target for myocardial IRI treatment.

Analysis and identification of potential key genes in hepatic ischemia-reperfusion injury

Background

Hepatic ischemia-reperfusion injury (HIRI) is an unavoidable surgical complication after liver transplantation, but current HIRI treatments cannot achieve satisfactory clinical outcomes. Thus, safer and more effective prevention and treatment methods need to be explored.

Methods

Transcriptome messenger ribonucleic acid (mRNA) and long non-coding RNA (lncRNA) sequencing data were obtained from male Sprague-Dawley rats, and these data were used to identify the differentially expressed genes (DEGs) and differentially expressed lncRNAs (DE-lncRNAs) between the HIRI and control samples. A protein-protein interaction (PPI) network was also constructed for the DE-mRNAs to identify candidate genes, and the receiver operating characteristic curves of the 21 candidate genes were plotted to evaluate the diagnostic value of the candidate genes for HIRI. A random forest (RF) model, support vector machine model and generalized linear model were constructed based on the candidate genes. A gene set enrichment analysis (GSEA) of the key genes was conducted to determine the enriched pathways in the high expression groups. The miRWalk and miRanda database were used to constructed the lncRNA-miRNA-mRNA network. Finally, the expressions of the key genes were verified by quantitative real-time polymerase chain reaction (qRT-PCR).

Results

A total of 256 DEGs and 67 DE-lncRNAs were identified in the HIRI and control samples. To explore the interactions between the DE-mRNAs, a PPI network of 130 DEGs was constructed. Further, 21 genes were selected as the candidate genes. Subsequently, 6 genes [i.e., Keratin-14 (Krt14), Uroplakin 3B (Upk3b), Keratin 7 (Krt7), Cadherin 3 (Cdh3), mesothelin (Msln), and Glypican 3 (Gpc3)] in the RF model were defined as the key genes. The GSEA results indicated that these key genes were enriched in the terms of extracellular structure organization, and extracellular matrix organization. Moreover, a lncRNA-miRNA-mRNA network was constructed with 4 lncRNAs, 5 mRNAs, and 11 miRNAs. Finally, the results indicated that the expression of Krt14, Upk3b, Msln, and Gpc3 were more highly expressed in the control samples than the HIRI samples.

Conclusions

A total of 6 key genes (i.e., Krt14, Upk3b, Krt7, Cdh3, Msln, and Gpc3) were identified. Our findings provide novel ideas for the diagnosis and treatment of HIRI.

Silencing lncRNA KCNQ1OT1 reduced hepatic ischemia reperfusion injury-induced pyroptosis by regulating miR-142a-3p/HMGB1 axis

BACKGROUND

Based on pre-existing evidence, KCNQ1OT1 has been pointed out to be closely related to myocardial and cerebral ischemia reperfusion injury diseases. Herein, the objective of our study is to probe into the potential function as well as the underlying mechanism of KCNQ1OT1 on hepatic ischemia reperfusion injury (HIRI).

METHODS

Using C57BL/6 J mice and primary mouse hepatocytes were conducted to establish HIRI model in vivo and in vitro. Cell viability was examined using CCK-8 assay and EdU assay. Flow cytometric analysis was performed to evaluate the pyroptosis. Dual-luciferase reporter assay was employed to verify the interaction relationships. qRT-PCR and Western blot were adopted to analyze the mRNA and protein level. Histopathological alteration of liver tissue was evaluated by HE staining. Immunohistochemistry (IHC) was performed to measure NLRP3 and caspase 1.

RESULTS

Our data revealed that KCNQ1OT1 expression was ascending in hepatic tissue of HIRI mouse. Moreover, deprivation of KCNQ1OT1 mitigated I/R-induced hepatic injury and pyroptosis in vivo. Further experiments demonstrated that silencing KCNQ1OT1 promoted proliferation and inhibited pyroptosis in hypoxia/reoxygenation (H/R)-induced primary mouse hepatocytes. Mechanistically, KCNQ1OT1 functioned as a competing endogenous RNA which sponged miR-142a-3p, therefore promoted HMGB1 expression to activate TLR4/NF-κB signaling pathway in HIRI.

CONCLUSION

LncRNA KCNQ1OT1 elevated HMGB1 expression through binding to miR-142a-3p, thereby promoting pyroptosis in HIRI.

Combined Systemic Intake of K-ATP Opener (Nicorandil) and Mesenchymal Stem Cells Preconditioned With Nicorandil Alleviates Pancreatic Insufficiency in a Model of Bilateral Renal Ischemia/Reperfusion Injury

We used nicorandil, a K-ATP channel opener, to study the role of these channels in the amelioration of renal ischemia/reperfusion (I/R)-induced pancreatic injury, and the possible involvement of PI3K/Akt/mTOR signaling pathway. Forty-two male Wistar rats were included in this study, six were sacrificed for extraction of bone marrow mesenchymal stem cells (BM-MSCs) and conducting the in-vitro work, the others were included in vivo study and equally divided into six groups. Group 1 (sham control), but groups 2–6 were subjected to bilateral renal I/R: Group 2 (I/R); Group 3 (I/R-NC), treated with nicorandil; Group 4 (I/R-MSCs), treated with BM-MSCs; Group 5 (I/R-MSCC), treated with nicorandil-preconditioned BM-MSCs; Group 6 (I/R-NC-MSCC), treated with both systemic nicorandil and preconditioned BM-MSCC. Renal injury and subsequent pancreatic damage were detected in the I/R group by a significant increase in serum urea, creatinine, fasting glucose, and pancreatic enzymes. The pancreatic tissues showed a reduction in cellularity and a significant decrease in the expression of the cell survival pathway, PI3K/Akt/mTOR, in the I/R group compared to the control. Preconditioning MSCs with nicorandil significantly enhanced the proliferation assay and decreased their apoptotic markers. Indeed, combined systemic nicorandil and nicorandil-preconditioning maintained survival of MSC in the pancreatic tissue and amelioration of apoptotic markers and pancreatic TNF-α production. Histologically, all treated groups revealed better pancreatic architecture, and increased area % of anti-insulin antibody and CD31, which were all best observed in the NC-MSCC group. Thus, using K-ATP channel opener was efficient to enhance PI3K/Akt/mTOR expression levels (in vivo and in vitro).

Purple Corn Extract Improves Benign Prostatic Hyperplasia by Regulating Prostate Cell Proliferation and Apoptosis

Purple corn (Zea mays L.), utilized as a natural pigment in food production and processing, has been used to treat obesity, cystitis, and urinary tract infections. However, no reports of its use for benign prostatic hyperplasia (BPH) exist. Purple corn extract (PCE) contains anthocyanins, particularly cyanidin-3-O-glucoside, which have various pharmacological characteristics. Therefore, this study sought to elucidate the ameliorative effect of PCE on BPH in dihydrotestosterone (DHT)-stimulated WPMY-1 cells and testosterone propionate (TP)-induced rats. Expression levels of the upregulated androgen receptor (AR) and its related genes in DHT-stimulated WPMY-1 cells were reduced by PCE, and proapoptotic gene expression increased by modulating the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling cascade. PCE reduced the weight of the enlarged prostate by inhibiting the androgen/AR signaling-related markers. Histological variations in the prostate epithelium caused by TP injection were restored by PCE. Thus, PCE alleviates BPH by modulating prostate cell proliferation and apoptosis.

Arrb2 causes hepatic lipid metabolism disorder via AMPK pathway based on metabolomics in alcoholic fatty liver

BACKGROUND AND AIMS

Alcoholic fatty liver (AFL) is an early form of alcoholic liver disease (ALD) that usually manifests as lipid synthesis abnormalities in hepatocytes. β-arrestin2 (Arrb2) is involved in multiple biological processes. The present study aimed to explore the role of Arrb2 in the regulation of lipid metabolism in AFL and the underlying mechanism and identify potential targets for the treatment of AFL.

METHODS

The expression of Arrb2 was detected in liver tissues obtained from AFL patients and Gao-binge AFL model mice. In addition, we specifically knocked down Arrb2 in AFL mouse liver in vivo and used Arrb2-siRNA or pEX3-Arrb2 to silence or overexpress Arrb2 in AML-12 cells in vitro to explore the functional role and underlying regulatory mechanism of Arrb2 in AFL. Finally, we investigated whether Arrb2 could cause changes in hepatic lipid metabolites, thereby leading to dysregulation of lipid metabolism based on liquid chromatography-mass spectrometry (LC-MS) analysis.

RESULTS

Arrb2 was up-regulated in the livers of AFL patients and AFL mice. The in vivo and in vitro results confirmed that Arrb2 could induce lipid accumulation and metabolism disorders. Mechanistically, Arrb2 induced hepatic metabolism disorder via AMP-activated protein kinase (AMPK) pathway. The results of LC-MS analysis revealed that hepatic lipid metabolites with the most significant differences were primary bile acids.

CONCLUSIONS

Arrb2 induces hepatic lipid metabolism disorders via AMPK pathway in AFL. On one hand, Arrb2 increases fatty acid synthesis. On the other hand, Arrb2 could increase the cholesterol synthesis, thereby leading to the up-regulation of primary bile acid levels.

β-Arrestin2 Inhibits the Apoptosis and Facilitates the Proliferation of Fibroblast-like Synoviocytes in Diffuse-type Tenosynovial Giant Cell Tumor

BACKGROUND/AIM

Diffuse-type tenosynovial giant cell tumor (TGCT) is a rare benign proliferative synovial neoplasm of uncertain etiology, and the efficacy of surgical resection is not satisfactory. Therefore, there is an urgent need to explore the pathogenesis and identify novel therapeutic targets for TGCT.

MATERIALS AND METHODS

Synovial tissues were collected from patients with TGCT and osteoarthritis (OA). Differences of mRNA expression between TGCT and OA were explored using mRNA-seq. In addition, fibroblast-like synoviocytes (FLS) were treated with small interfering RNA (siRNA) or adenovirus in order to knockdown or overexpress β-arrestin2 (Arrb2), respectively. FLS proliferation and apoptosis were evaluated using the MTT assay and the caspase 3 activity assay, respectively.

RESULTS

The expression of Arrb2 in TGCT was significantly higher than that in OA. The overexpression of Arrb2 promoted the proliferation of FLS and inhibited its apoptosis, while knocking down Arrb2 had the opposite effect. Further studies showed that Arrb2 can activate the PI3K-Akt signaling pathway, leading to increased proliferation of TGCT.

CONCLUSION

Arrb2 facilitates the proliferation and inhibits the apoptosis of TGCT FLS through activating the PI3K-Akt cell survival pathway, providing new insight into the molecular mechanism of TGCT.