The PI3K/AKT signaling pathway in regulatory T-cell development, stability, and function

Prevalence of intratumoral regulatory T cells expressing neuropilin-1 is associated with poorer outcomes in patients with cancer

[Figure: see text].

Proteomic Studies on the Mechanism of Myostatin Regulating Cattle Skeletal Muscle Development

Myostatin (MSTN) is an important negative regulator of muscle growth and development. In this study, we performed comparatively the proteomics analyses of gluteus tissues from MSTN^+/− Mongolian cattle (MG.MSTN^+/−) and wild type Mongolian cattle (MG.WT) using a shotgun-based tandem mass tag (TMT) 6-plex labeling method to investigate the regulation mechanism of MSTN on the growth and development of bovine skeletal muscle. A total of 1,950 proteins were identified in MG.MSTN^+/− and MG.WT. Compared with MG.WT cattle, a total of 320 differentially expressed proteins were identified in MG.MSTN cattle, including 245 up-regulated differentially expressed proteins and 75 down-regulated differentially expressed proteins. Bioinformatics analysis showed that knockdown of the MSTN gene increased the expression of extracellular matrix and ribosome-related proteins, induced activation of focal adhesion, PI3K-AKT, and Ribosomal pathways. The results of proteomic analysis were verified by muscle tissue Western blot test and in vitro MSTN gene knockdown test, and it was found that knockdown MSTN gene expression could promote the proliferation and myogenic differentiation of bovine skeletal muscle satellite cells (BSMSCs). At the same time, Co-Immunoprecipitation (CO-IP) assay showed that MSTN gene interacted with extracellular matrix related protein type I collagen α 1 (COL1A1), and knocking down the expression of COL1A1 could inhibit the activity of adhesion, PI3K-AKT and ribosome pathway, thus inhibit BSMSCs proliferation. These results suggest that the MSTN gene regulates focal adhesion, PI3K-AKT, and Ribosomal pathway through the COL1A1 gene. In general, this study provides new insights into the regulatory mechanism of MSTN involved in muscle growth and development.

MiR-1246 regulates the PI3K/AKT signaling pathway by targeting PIK3AP1 and inhibits thyroid cancer cell proliferation and tumor growth

One of the most prevalent forms of endocrine malignancies is thyroid cancer. Herein, we explored the mechanisms whereby miR-1246 is involved in thyroid cancer. Phosphoinositide 3-kinase adapter protein 1 (PIK3AP1) was identified as a potential miR-1246 target, with the online Gene Expression Omnibus (GEO) database. The binding between miR-1246 and PIK3AP1 and the dynamic role of these two molecules in downstream PI3K/AKT signaling were evaluated. Analysis of GEO data demonstrated significant miR-1246 downregulation in thyroid cancer, and we confirmed that overexpression of miR-1246 can inhibit migratory, invasive, and proliferative activity in vitro and tumor growth in vivo. Subsequent studies indicated that miR-1246 overexpression decreased the protein level of PIK3AP1 and the phosphorylation of PI3K and AKT, which were reversed by PIK3AP1 overexpression. At the same time, overexpression of PIK3AP1 also reversed the miR-1246 mimics-induced inhibition proliferative, migratory, and invasive activity, while promoting increases in apoptotic death, confirming that miR-1246 function was negatively correlated with that of PIK3AP1. Subsequently, we found that the miR-1246 mimics-induced inhibition of PI3K/AKT phosphorylation was reversed by the PI3K/AKT activator IGF-1. miR-1246 mimics inhibited proliferative, migratory, and invasive activity while promoting increases in apoptotic death, which were reversed by IGF-1. Furthermore, miR-1246 agomir can inhibit tumor growth in vivo. We confirmed that miR-1246 affects the signaling pathway of PI3K/AKT via targeting PIK3AP1 and inhibits the development of thyroid cancer. Thus, miR-1246 is a new therapeutic target for thyroid cancer.

Inhibition of integrin subunit alpha 11 restrains gastric cancer progression through phosphatidylinositol 3-kinase/Akt pathway

Gastric cancer (GC) is among the most frequent malignancies originating from the digestive system worldwide, while the role and specific mechanism of integrin-subunit alpha 11 (ITGA11) in GC remain unclear. This study probes the expression characteristics and function of ITGA11 in GC. Firstly, the ITGA11 profile in GC tissues and paracancerous non-tumor tissues was assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot (WB), and the association between ITGA11 and GC patients' clinicopathological indicators was evaluated. ITGA11 knockdown models were set up in GC cell lines MKN45 and AGS. Cell proliferation was determined by the cell counting kit-8 (CCK-8) assay and colony formation assay. WB was utilized to gauge the expression of apoptosis-related proteins (Bax, Bcl2, Bad, and C-Caspase3) and the PI3K/AKT pathway. We discovered that the ITGA11 expression was boosted in GC tissues and was related to the unfavorable prognosis of GC patients. Additionally, ITGA11 knockdown abated GC cell proliferation, invasion and migration, and enhanced cell apoptosis. In animal experiments, the tumorigenesis of GC cells knocking down ITGA11 was reduced. Mechanically, knocking down ITGA11 notably inactivated the PI3K/AKT axis. The tumor-suppressive effect mediated by ITGA11 knockdown was attenuated after activating the PI3K/AKT pathway with insulin-like growth factor 1 (IGF-1). Overall, this study substantiated that the ITGA11 expression was heightened in GC tissues, which affected GC progression by modulating the PI3K/AKT pathway.

Berberine inhibited carotid atherosclerosis through PI3K/AKTmTOR signaling pathway

Atherosclerosis, a multifactorial vascular disease resulting from lipid metabolism disorders, features chronic inflammatory damage resulting from endothelial dysfunction, which usually affects multiple arteries. The carotid artery is a common site for clinical atherosclerosis evaluation. The aortic root is the standard site for quantifying atherosclerosis in mice. Due to the adverse reactions of first-line drugs, it is necessary to discover new drugs to prevent and treat atherosclerosis. Berberine (BBR) is one of the most promising natural products derived from herbal medicine Coptidis Rhizoma (Huanglian) that features significant anti-atherosclerosis properties. However, overall BBR mechanism against carotid atherosclerosis has not been clearly discovered. Our work aimed to investigate potential BBR mechanism in improving carotid atherosclerosis in ApoE knockout mice. Here, we proved that in ApoE -/- mice receiving high-fat diet for 12 weeks, BBR can reduce serum lipid levels, improve intimal hyperplasia, and antagonize carotid lipid accumulation, which may be achieved through regulating the PI3K/AKT/mTOR signaling pathway, regulating autophagy, promoting cell proliferation and inhibiting cell apoptosis. In summary, these data indicate that BBR can ameliorate carotid atherosclerosis. Therefore, it could be a promisingly therapeutic alternative for atherosclerosis.

ALKBH5-mediated m6A demethylation of KCNK15-AS1 inhibits pancreatic cancer progression via regulating KCNK15 and PTEN/AKT signaling

Long noncoding RNAs (lncRNAs) are regarded as crucial regulators in tumor progression. Potassium two pore domain channel subfamily K member 15 and WISP2 antisense RNA 1 (KCNK15-AS1) has been confirmed to inhibit the migration and invasion of pancreatic cancer (PC) cells. However, its downstream mechanism and effect on other cellular functions in PC remain unknown. This study probed the function and potential mechanism of KCNK15-AS1 in PC cell growth. RT-qPCR and western blot were employed to measure gene expression in PC cells. ISH was applied to analyze KCNK15-AS1 expression in PC tissues. Functional assays were utilized to evaluate PC cell proliferation, apoptosis, migration and EMT. Mechanical experiments were adopted to detect gene interaction in PC cells. The obtained data indicated that KCNK15-AS1 was down-regulated in PC cells and tissues. Overexpressing KCNK15-AS1 hindered cell proliferation, migration and EMT while facilitated cell apoptosis in PC. Mechanically, alkylation repair homolog protein 5 (ALKBH5) was verified to induce m6A demethylation of KCNK15-AS1 to mediate KCNK15-AS1 up-regulation. KCNK15-AS1 combined with KCNK15 5'UTR to inhibit KCNK15 translation. Moreover, KCNK15-AS1 recruited MDM2 proto-oncogene (MDM2) to promote RE1 silencing transcription factor (REST) ubiquitination, thus transcriptionally upregulating phosphatase and tensin homolog (PTEN) to inactivate AKT pathway. In conclusion, our study first confirmed that KCNK15-AS1 hinders PC cell growth by regulating KCNK15 and PTEN, suggesting KCNK15-AS1 as a potential biomarker of PC.

Adeno-Associated Viruses (AAV) and Host Immunity - A Race Between the Hare and the Hedgehog

Adeno-associated viruses (AAV) have emerged as the lead vector in clinical trials and form the basis for several approved gene therapies for human diseases, mainly owing to their ability to sustain robust and long-term in vivo transgene expression, their amenability to genetic engineering of cargo and capsid, as well as their moderate toxicity and immunogenicity. Still, recent reports of fatalities in a clinical trial for a neuromuscular disease, although linked to an exceptionally high vector dose, have raised new caution about the safety of recombinant AAVs. Moreover, concerns linger about the presence of pre-existing anti-AAV antibodies in the human population, which precludes a significant percentage of patients from receiving, and benefitting from, AAV gene therapies. These concerns are exacerbated by observations of cellular immune responses and other adverse events, including detrimental off-target transgene expression in dorsal root ganglia. Here, we provide an update on our knowledge of the immunological and molecular race between AAV (the “hedgehog”) and its human host (the “hare”), together with a compendium of state-of-the-art technologies which provide an advantage to AAV and which, thus, promise safer and more broadly applicable AAV gene therapies in the future.

RvD1 treatment during primary infection modulates memory response increasing viral load during respiratory viral reinfection

Resolvin D1 (RvD1), which is biosynthesized from essential long-chain fatty acids, is involved in anti-inflammatory activity and modulation of T cell response. Memory CD8+ T cells are important for controlling tumor growth and viral infections. Exacerbated inflammation has been described as impairing memory CD8+ T cell differentiation. This study aimed to verify the effects of RvD1 on memory CD8+ T cells in vitro and in vivo in a respiratory virus infection model. Peripheral blood mononuclear cells were treated at different time points with RvD1 and stimulated with anti-CD3/anti-CD28 antibodies. Pre-treatment with RvD1 increases the expansion of memory CD8+ T cells. The IL-12 level, a cytokine described to control memory CD8+ T cells, was reduced with RvD1 pre-treatment. When the mTOR axis was inhibited, the IL-12 levels were restored. In a respiratory virus infection model, Balb/c mice were treated with RvD1 before infection or after 7 days after infection. RvD1 treatment after infection increased the frequency of memory CD8+ T cells in the lung expressing II4, II10, and Ifng. During reinfection, RvD1-treated and RSV-infected mice present a high viral load in the lung and lower antibody response in the serum. Our results show that RvD1 modulates the expansion and phenotype of memory CD8+ T cells but contributed to a non-protective response after RSV reinfection.

Syngeneic bone marrow transplantation in combination with PI3K inhibitor reversed hyperglycemia in later-stage streptozotocin-induced diabetes

Background

Type 1 diabetes (T1D) is a multiple factor autoimmune disease characterized by T cell-mediated immune destruction of islet β cells. Autologous hematopoietic stem cell transplantation (AHSCT) has been a novel strategy for patients with new-onset T1D, but not for those with a later diagnosis. Disturbance of regulatory T cells (Tregs) likely contributes to poor response after transplantation in later-stage T1D. Inhibition of phosphoinositide 3-kinases (PI3K)/Akt signaling maintains Tregs’ homeostasis.

Methods

We built a later-stage streptozotocin (STZ)-induced T1D mouse model. Syngeneic bone marrow transplantation (syn-BMT) was performed 20 days after the onset of diabetes in combination with BKM120 (a PI3K inhibitor). Meanwhile, another group of STZ-diabetic mice were transplanted with bone marrow cells cocultured with BKM120 in vitro for 24 h. Fasting glucose and glucose tolerance were recorded during the entire experimental observation after syn-BMT. Samples were collected 126 days after syn-BMT. Hematoxylin and eosin (H&E) staining was used to detect the effect of PI3K inhibitor combined with syn-BMT on morphology of the T1D pancreas. CD4⁺CD25⁻ T cells and CD4⁺CD25⁺ T cells were sorted by magnetic cell sorting (MACS), then fluorescence activated cell sorting (FACS) and quantitative real-time PCR (qPCR) were used to detect the effect of PI3K inhibitor on modulating immune disorder and restoring the function of Treg cells.

Results

Our investigation showed syn-BMT in combination with BKM120 effectively maintained normoglycemia in later-stage T1D. The disease remission effects may be induced by the rebalance of Th17/Tregs dysregulation and restoration of Tregs’ immunosuppressive function by BKM120 after syn-BMT.

Conclusions

These results may reveal important connections for PI3K/Akt inhibition and Tregs’ homeostasis in T1D after transplantation. AHSCT combining immunoregulatory strategies such as PI3K inhibition may be a promising therapeutic approach in later-stage T1D.

Annexin A3 and cancer

Annexin A3 (ANXA3), an annexin family member, contains 36 kDa and 33 kDa isoforms. Similar to other annexin members, ANXA3 plays an important role in the development of human diseases. Recent studies have reported that abnormal ANXA3 expression is closely associated with the development, progression, metastasis, drug resistance and prognosis of several malignant tumours, such as breast cancer, lung cancer and hepatocellular carcinoma. ANXA3 exerts its role by regulating cell proliferation, migration and apoptosis via the phosphatidylinositol-3 kinase/Akt, nuclear factor-κB (NF-κB), c-JUN N-terminal kinase, extracellular signal-regulated kinase and hypoxia-inducible factor-1 signalling pathways. ANXA3 may act as a novel target for the early diagnosis and treatment of tumours. The present review summarises the recent progress in the role of ANXA3 and its regulatory pathways in tumours.

The Expression Regulatory Network in the Lung Tissue of Tibetan Pigs Provides Insight Into Hypoxia-Sensitive Pathways in High-Altitude Hypoxia

To adapt to a low-oxygen environment, Tibetan pigs have developed a series of unique characteristics and can transport oxygen more effectively; however, the regulation of the associated processes in high-altitude animals remains elusive. We performed mRNA-seq and miRNA-seq, and we constructed coexpression regulatory networks of the lung tissues of Tibetan and Landrace pigs. HBB, AGT, COL1A2, and EPHX1 were identified as major regulators of hypoxia-induced genes that regulate blood pressure and circulation, and they were enriched in pathways related to signal transduction and angiogenesis, such as HIF-1, PI3K-Akt, mTOR, and AMPK. HBB may promote the combination of hemoglobin and oxygen as well as angiogenesis for high-altitude adaptation in Tibetan pigs. The expression of MMP2 showed a similar tendency of alveolar septum thickness among the four groups. These results indicated that MMP2 activity may lead to widening of the alveolar wall and septum, alveolar structure damage, and collapse of alveolar space with remarkable fibrosis. These findings provide a perspective on hypoxia-adaptive genes in the lungs in addition to insights into potential candidate genes in Tibetan pigs for further research in the field of high-altitude adaptation.

Integrated Network Analysis to Identify Key Modules and Potential Hub Genes Involved in Bovine Respiratory Disease: A Systems Biology Approach

Background: Bovine respiratory disease (BRD) is the most common disease in the beef and dairy cattle industry. BRD is a multifactorial disease resulting from the interaction between environmental stressors and infectious agents. However, the molecular mechanisms underlying BRD are not fully understood yet. Therefore, this study aimed to use a systems biology approach to systematically evaluate this disorder to better understand the molecular mechanisms responsible for BRD. Methods: Previously published RNA-seq data from whole blood of 18 healthy and 25 BRD samples were downloaded from the Gene Expression Omnibus (GEO) and then analyzed. Next, two distinct methods of weighted gene coexpression network analysis (WGCNA), i.e., module-trait relationships (MTRs) and module preservation (MP) analysis were used to identify significant highly correlated modules with clinical traits of BRD and non-preserved modules between healthy and BRD samples, respectively. After identifying respective modules by the two mentioned methods of WGCNA, functional enrichment analysis was performed to extract the modules that are biologically related to BRD. Gene coexpression networks based on the hub genes from the candidate modules were then integrated with protein-protein interaction (PPI) networks to identify hub-hub genes and potential transcription factors (TFs). Results: Four significant highly correlated modules with clinical traits of BRD as well as 29 non-preserved modules were identified by MTRs and MP methods, respectively. Among them, two significant highly correlated modules (identified by MTRs) and six nonpreserved modules (identified by MP) were biologically associated with immune response, pulmonary inflammation, and pathogenesis of BRD. After aggregation of gene coexpression networks based on the hub genes with PPI networks, a total of 307 hub-hub genes were identified in the eight candidate modules. Interestingly, most of these hub-hub genes were reported to play an important role in the immune response and BRD pathogenesis. Among the eight candidate modules, the turquoise (identified by MTRs) and purple (identified by MP) modules were highly biologically enriched in BRD. Moreover, STAT1, STAT2, STAT3, IRF7, and IRF9 TFs were suggested to play an important role in the immune system during BRD by regulating the coexpressed genes of these modules. Additionally, a gene set containing several hub-hub genes was identified in the eight candidate modules, such as TLR2, TLR4, IL10, SOCS3, GZMB, ANXA1, ANXA5, PTEN, SGK1, IFI6, ISG15, MX1, MX2, OAS2, IFIH1, DDX58, DHX58, RSAD2, IFI44, IFI44L, EIF2AK2, ISG20, IFIT5, IFITM3, OAS1Y, HERC5, and PRF1, which are potentially critical during infection with agents of bovine respiratory disease complex (BRDC). Conclusion: This study not only helps us to better understand the molecular mechanisms responsible for BRD but also suggested eight candidate modules along with several promising hub-hub genes as diagnosis biomarkers and therapeutic targets for BRD.

IL-35 promotes CD4+Foxp3+ Tregs and inhibits atherosclerosis via maintaining CCR5-amplified Treg-suppressive mechanisms

Tregs play vital roles in suppressing atherogenesis. Pathological conditions reshape Tregs and increase Treg-weakening plasticity. It remains unclear how Tregs preserve their function and how Tregs switch into alternative phenotypes in the environment of atherosclerosis. In this study, we observed a great induction of CD4⁺Foxp3⁺ Tregs in the spleen and aorta of ApoE^–/– mice, accompanied by a significant increase of plasma IL-35 levels. To determine if IL-35 devotes its role in the rise of Tregs, we generated IL-35 subunit P35–deficient (IL-35P35–deficient) mice on an ApoE^–/– background and found Treg reduction in the spleen and aorta compared with ApoE^–/– controls. In addition, our RNA sequencing data show the elevation of a set of chemokine receptor transcripts in the ApoE^–/– Tregs, and we have validated higher CCR5 expression in ApoE^–/– Tregs in the presence of IL-35 than in the absence of IL-35. Furthermore, we observed that CCR5⁺ Tregs in ApoE^–/– have lower Treg-weakening AKT-mTOR signaling, higher expression of inhibitory checkpoint receptors TIGIT and PD-1, and higher expression of IL-10 compared with WT CCR5⁺ Tregs. In conclusion, IL-35 counteracts hyperlipidemia in maintaining Treg-suppressive function by increasing 3 CCR5-amplified mechanisms, including Treg migration, inhibition of Treg weakening AKT-mTOR signaling, and promotion of TIGIT and PD-1 signaling.

Antagonizing effects of curcumin against mercury-induced autophagic death and trace elements disorder by regulating PI3K/AKT and Nrf2 pathway in the spleen

Mercury is a naturally occurring element and highly toxic to humans even at a low dosage. Curcumin is a polyphenol found in turmeric (Curcuma longa), widely used as a treatment strategy to improve antioxidant and anti-inflammatory properties. The purpose of this study was to investigate the potential protective mechanisms of curcumin in spleen damage induced by HgCl₂. The mice were given curcumin by intragastric administration 2 h before HgCl₂ injection for 24 h. At first, splenic transcriptome analysis showed that 3334 genes (2134 up and 1200 down) were differently expressed in HgCl₂-induced spleen damage model. Notably, KEGG enrichment showed phosphatidylinositol 3-kinase (PI3K)-AKT might be a key signaling pathways in HgCl₂-induced spleen damage. Furthermore, our data demonstrated that HgCl₂ could induce autophagic cell death, evidenced by increases the protein expression of PI3K, AKT, LC3-II and p62 and the number of apoptotic cells. Furthermore, we found that curcumin significantly combated autophagic cell death, sodium overload and calcium leak induced by HgCl₂. Simultaneously, further studies demonstrated that curcumin significantly activated nuclear factor (erythroid-derived-2)-like 2 (Nrf2) signaling pathway, and subsequent enhancing antioxidant defenses. Taken together, our data indicated that inorganic mercury could result in autophagic cell death, which may be related to the regulation of PI3K-AKT signaling cascades. Furthermore, Nrf2-mediated antioxidant defenses may be the target of curcumin to confers an adaptive survival response to resist spleen damage induced by HgCl₂. The present study perfects the mechanism theory of HgCl₂-induced spleen damage and provides a way for pharmacological intervention to prevent spleen injury.

Uev1A promotes breast cancer cell migration by up-regulating CT45A expression via the AKT pathway

Background

UEV1A encodes a ubiquitin-E2 variant closely associated with tumorigenesis and metastasis, but its underlying mechanism in promoting metastasis remains to be investigated.

Methods

In this study, we experimentally manipulated UEV1A and CT45A gene expression and monitored their effects on cancer-related gene expression, cell migration and the signal transduction cascade.

Results

It was found that UEV1A overexpression induces CT45A family gene expression in breast cancer cells. Indeed, ectopic expression of UEV1A was sufficient to induce CT45A and its downstream genes involved in tumorigenesis, epithelial-mesenchymal transition (EMT), stemness and metastasis, and to promote cell migration and EMT signaling. Consistently, depletion of CT45A abolished the above effects, indicating that CT45A is a critical downstream effector of Uev1A. The Uev1A-induced cell migration and EMT signaling was dependent on AKT but independent of NF-κB, indicating that CT45A acts downstream of the AKT pathway.

Conclusions

Based on previous reports and observations in this study, we propose that the Ubc13-Uev1A complex activates AKT through K63-linked polyubiquitination, which leads to enhanced CT45A expression, stimulated cell migration and EMT signaling in breast cells. Since similar effects were also observed in a colorectal cancer cell line, the Ubc13/Uev1A-AKT-CT45A axis may also promote tumorigenesis and metastasis in other tissues.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08750-3.

Far infrared irradiation suppresses experimental arthritis in rats by down-regulation of genes involved inflammatory response and autoimmunity

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FIR treatment improved adjuvant arthritis in rats.

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FIR exposure inhibited the inflammatory genes expression of synovial tissues in AIA rats.

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FIR exposure down-regulated inflammatory genes expression mainly through transcription factors AP-1, CEBPα, CEBPβ, c-Fos, GR, HNF-3β, USF-1, and USF-2.

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FIR irradiation may exhibit anti-arthritic effects through inactivation of the MAPK, PI3K-Akt, and NF-κB signaling pathways.

Introduction

Objectives

Methods

Results

Conclusion

MicroRNAs in organ fibrosis: From molecular mechanisms to potential therapeutic targets

Fibrosis is caused by chronic tissue injury and characterized by the excessive deposition of extracellular matrix (ECM) that ultimately results in organ failure and death. Owing to lacking of effective treatment against tissue fibrosis, it causes a high morbidity and mortality worldwide. Thus, it is of great importance to find an effective therapy strategy for the treatment of fibrosis. MicroRNAs (miRNAs) play vital roles in many biological processes by targeting downstream genes. Numerous studies demonstrated that miRNAs served as biomarkers of various diseases, suggesting the potential therapeutic targets for diseases. It was recently reported that miRNAs played an important role in the development of organ fibrosis, which showed a promising prospect against fibrosis by targeting intervention. Here, we summarize the roles of miRNAs in the process of organ fibrosis, including liver, lung, heart and kidney, and highlight miRNAs being novel therapeutic targets for organ fibrosis.

Protein phosphatase 6 (Pp6) is crucial for regulatory T cell function and stability in autoimmunity

Regulatory T (T_reg) cells constitute a dynamic population that is critical in autoimmunity. T_reg cell therapies for autoimmune diseases are mainly focused on enhancing their suppressive activities. However, recent studies demonstrated that certain inflammatory conditions induce T_reg cell instability with diminished FoxP3 expression and convert them into pathogenic effector cells. Therefore, the identification of novel targets crucial to both T_reg cell function and plasticity is of vital importance to the development of therapeutic approaches in autoimmunity. In this study, we found that conditional Pp6 knockout (cKO) in T_reg cells led to spontaneous autoinflammation, immune cell activation, and diminished levels of FoxP3 in CD4⁺ T cells in mice. Loss of Pp6 in T_reg cells exacerbated two classical mouse models of T_reg-related autoinflammation. Mechanistically, Pp6 deficiency increased CpG motif methylation of the FoxP3 locus by dephosphorylating Dnmt1 and enhancing Akt phosphorylation at Ser473/Thr308, leading to impaired FoxP3 expression in T_reg cells. In summary, our study proposes Pp6 as a critical positive regulator of FoxP3 that acts by decreasing DNA methylation of the FoxP3 gene enhancer and inhibiting Akt signaling, thus maintaining T_reg cell stability and preventing autoimmune diseases.

The Importance of Being PI3K in the RAS Signaling Network

Ras proteins are essential mediators of a multitude of cellular processes, and its deregulation is frequently associated with cancer appearance, progression, and metastasis. Ras-driven cancers are usually aggressive and difficult to treat. Although the recent Food and Drug Administration (FDA) approval of the first Ras G12C inhibitor is an important milestone, only a small percentage of patients will benefit from it. A better understanding of the context in which Ras operates in different tumor types and the outcomes mediated by each effector pathway may help to identify additional strategies and targets to treat Ras-driven tumors. Evidence emerging in recent years suggests that both oncogenic Ras signaling in tumor cells and non-oncogenic Ras signaling in stromal cells play an essential role in cancer. PI3K is one of the main Ras effectors, regulating important cellular processes such as cell viability or resistance to therapy or angiogenesis upon oncogenic Ras activation. In this review, we will summarize recent advances in the understanding of Ras-dependent activation of PI3K both in physiological conditions and cancer, with a focus on how this signaling pathway contributes to the formation of a tumor stroma that promotes tumor cell proliferation, migration, and spread.

TCMIP v2.0 Powers the Identification of Chemical Constituents Available in Xinglou Chengqi Decoction and the Exploration of Pharmacological Mechanisms Acting on Stroke Complicated With Tanre Fushi Syndrome

Xinglou Chengqi (XLCQ) decoction, composed of three botanical drugs and one inorganic drug, is used in clinics during the treatment of acute stroke complicated with Tanre Fushi (TRFS) syndrome in China. However, its active ingredients and the molecular mechanism have not been clarified. So, we aimed to preliminarily characterize its chemical constituents and investigate its pharmacological mechanisms using an integrative pharmacology strategy, including component analysis, network prediction, and experimental verification. We employed UPLC-QTOF-MS/MS to describe the chemical profile of XLCQ, Integrative Pharmacology-based Network Computational Research Platform of Traditional Chinese Medicine (TCMIP v2.0, http://www.tcmip.cn/), to assist in identifying the chemical components and predict the putative molecular mechanism against acute stroke complicated with TRFS, and LPS-stimulated BV-2 cells to verify the anti-neuroinflammatory effects of luteolin, apigenin, and chrysoeriol. Altogether, 197 chemical compounds were identified or tentatively characterized in the water extraction of XLCQ, 22 of them were selected as the key active constituents that may improve the pathological state by regulating 27 corresponding targets that are mainly involved in inflammation/immune-related pathways, and furthermore, luteolin, apigenin, and chrysoeriol exhibited good anti-neuroinflammatory effects from both protein and mRNA levels. In summary, it is the first time to employ an integrative pharmacology strategy to delineate 22 constituents that may improve the pathological state of stroke with TRFS by regulating 27 corresponding targets, which may offer a highly efficient way to mine the scientific connotation of traditional Chinese medicine prescriptions. This study might be a supplement for the deficiency of the basic research of XLCQ.

Resveratrol activates PI3K/AKT to reduce myocardial cell apoptosis and mitochondrial oxidative damage caused by myocardial ischemia/reperfusion injury

Resveratrol is a kind of iPolyphenols widely existing in herbal medicine. Here we aim to investigate whether resveratrol can reduce the degree of myocardial ischemia/reperfusion (IR) injury and inhibit the development of oxidative stress, and elucidate the molecular mechanism of resveratrol in protecting myocardial cells. The primary rat cardiomyocytes were used to establish an ischemia/reperfusion model in vitro, and a series of routine biochemical experiments were conducted to explore the antioxidant and anti-apoptotic effects of resveratrol in myocardial ischemia-reperfusion injury. Compared with that of the simulated ischemia-refusion (SIR) group, cell viability in the SIR and resveratrol co-treatment groups increased significantly (P < 0.001), the release of lactate dehydrogenase (LDH) and creatine kinase MB (CKMB) decreased, the positive rate of reactive oxygen species (ROS) in cardiomyocytes decreased, and the concentration of catalase and glutathione peroxidase increased significantly (P < 0.001). Besides, resveratrol can activate PI3K/AKT signaling pathway. PI3K siRNA can inhibit the PI3K/AKT signaling mediated by resveratrol. The addition of resveratrol can significantly increase the activity of mitochondrial superoxide dismutase (SOD) and reduce the malondialdehyde (MDA), which indicates that the oxidative damage of mitochondria induced by resveratrol was significantly weakened. The mitochondrial functional changes induced by resveratrol can be reversed by PI3K siRNA. In conclusion, our study shows that resveratrol can reduce ROS in cardiomyocytes by PI3K/AKT signaling pathway activation, and effectively inhibit the apoptosis of cardiomyocytes, thus having a direct protective effect on cardiomyocytes under SR.

Protective Effect of GM1 Attenuates Hippocampus and Cortex Apoptosis After Ketamine Exposure in Neonatal Rat via PI3K/AKT/GSK3β Pathway

Ketamine is a widely used analgesic and anesthetic in obstetrics and pediatrics. Ketamine is known to promote neuronal death and cognitive dysfunction in the brains of humans and animals during development. Monosialotetrahexosyl ganglioside (GM1), a promoter of brain development, exerts neuroprotective effects in many neurological disease models. Here, we investigated the neuroprotective effect of GM1 and its potential underlying mechanism against ketamine-induced apoptosis of rats. Seven-day-old Sprague Dawley (SD) rats were randomly divided into the following four groups: (1) group C (control group: normal saline was injected intraperitoneally); (2) group K (ketamine); (3) group GM1 (GM1 was given before normal saline injection); and (4) GM1+K group (received GM1 30 min before continuous exposure to ketamine). Each group contained 15 rats, received six doses of ketamine (20 mg/kg), and was injected with saline every 90 min. The Morris water maze (MWM) test, the number of cortical and hippocampal cells, apoptosis, and AKT/GSK3β pathway were analyzed. To determine whether GM1 exerted its effect via the PI3K/AKT/GSK3β pathway, PC12 cells were incubated with LY294002, a PI3K inhibitor. We found that GM1 protected against ketamine-induced apoptosis in the hippocampus and cortex by reducing the expression of Bcl-2 and Caspase-3, and by increasing the expression of Bax. GM1 treatment increased the expression of p-AKT and p-GSK3β. However, the anti-apoptotic effect of GM1 was eliminated after inhibiting the phosphorylation of AKT. We showed that GM1 lessens ketamine-induced apoptosis in the hippocampus and cortex of young rats by regulating the PI3K/AKT/GSK3β pathway. Taken together, GM1 may be a potential preventive treatment for the neurotoxicity caused by continuous exposure to ketamine.

Effects of TRIM59 on RAW264.7 macrophage gene expression and function

Macrophages have a variety of functions, such as secreting cytokines, phagocytosis, et al. Tripartite motif containing 59 (TRIM59) protein is highly expressed in tumor cells. It can regulate proliferation of tumor cells and promote tumor progression. Recent studies shown that the expression of TRIM59 was different in macrophages when stimulated by different stimuli, however, the effects of TRIM59 on macrophage gene expression profiles and functions are still unknown. In our study, we constructed RAW264.7 macrophages with high and low expression of TRIM59, and used next generation sequencing to explore the effects of TRIM59 on macrophage gene expression profiles. Results showed that TRIM59 affected an abundant number of genes, and may affect phagocytosis and cell cycles. We also examined the expression of surface molecules, secretion of cytokines, phagocytosis, proliferation, and apoptosis of macrophages, and confirmed that TRIM59 increased the expression of FcγRs CD16/32, CD64 and the secretion of TNF-α and IL-10, promoted phagocytosis and proliferation of RAW264.7 cells, inhibited the expression of complement receptor CD11b and antigen presentation related receptors (MHCII, CD80), but TRIM59 had no significant effect on apoptosis. Our study explored the effect of TRIM59 on the gene expression and function of macrophages comprehensively.

LINC00665 promotes the viability, migration and invasion of T cell acute lymphoblastic leukemia cells by targeting miR-101 via modulating PI3K/Akt pathway

T cell acute lymphoblastic leukemia (T-ALL) is a high-risk malignancy. The effects of cancer growth-related Long Intergenic Non-Protein Coding RNA 665 (LINC00665) in T-ALL remained obscure, and therefore further exploration was conducted on that in this study. The expression of LINC00665 in acute myeloid leukemia (LAML) tissues and myeloid tissues was analyzed using Gene Expression Profiling Interactive Analysis (GEPIA) 2. The target microRNA (miR) of LINC00665 was predicted by LncBase Predicted v.2 and verified using dual-luciferase reporter assay. After LINC00665 and miR-101 in T-ALL cells were overexpressed or silenced, the viability, migration and invasion of cell were detected using cell counting kit-8 and Transwell assays. The expressions of LINC00665, miR-101, Cyclin D1, Matrix metalloproteinases (MMP)-2, MMP-9, phosphorylated (p)-phosphatidylinositol 3-kinase (PI3K), PI3K, p-Akt, Akt were detected by quantitative real-time Polymerase Chain Reaction (qRT-PCR) and western blot. High expression of LINC00665 was presented in LAML tissues, the peripheral blood samples from patients with T-ALL and T-ALL cells. Overexpression of LINC00665 promoted the viability, migration and invasion of T-ALL cells and downregulated miR-101 expression, whereas silencing of LINC00665 did oppositely. MiR-101 could competitively bind to LINC00665, and was low-expressed in T-ALL. MiR-101 mimic inhibited viability, migration and invasion of T-ALL cells, and reversed effects of overexpressed LINC00665, whilst miR-101 inhibitor reversed the effects of LINC00665 silencing. Besides, overexpressed LINC00665 upregulated the expressions of Cyclin D1 MMP-2, and MMP-9 and the ratios of p-PI3K/PI3K and p-Akt/Akt, which were reversed by miR-101 mimic. LINC00665 could enhance the viability, migration and invasion abilities of T-ALL cells by targeting miR-101 via activating PI3K/Akt pathway.

miR‑130b regulates PTEN to activate the PI3K/Akt signaling pathway and attenuate oxidative stress‑induced injury in diabetic encephalopathy

Diabetic encephalopathy (DE) is one of the main chronic complications of diabetes, and is characterized by cognitive defects. MicroRNAs (miRNAs/miRs) are widely involved in the development of diabetes-related complications. The present study evaluated the role of miR-130b in DE and investigated its mechanisms of action. PC12 cells and hippocampal cells were exposed to a high glucose environment to induce cell injuries to mimic the in vitro model of DE. Cells were transfected with miR-130b mimic, miR-130b inhibitor and small interfering RNA (si)-phosphatase and tensin homolog (PTEN) to evaluate the protective effect of the miR-130b/PTEN axis against oxidative stress in high glucose-stimulated cells involving Akt activity. Furthermore, the effect of agomir-130b was also assessed on rats with DE. The expression of miR-130b was reduced in the DE models in vivo and in vitro. The administration of miR-130b mimic increased the viability of high glucose-stimulated cells, prevented apoptosis, increased the activity of superoxide dismutase (SOD), decreased the malondialdehyde (MDA) content, activated Akt protein levels and inhibited the mitochondria-mediated apoptotic pathway. The administration of miR-130b inhibitor exerted opposite effects, while si-PTEN reversed the effects of miR-130b inhibitor. In vivo, the administration of agomir-130b attenuated cognitive disorders and neuronal damage, increased SOD activity, reduced the MDA content, activated Akt protein levels and inhibited the mitochondria-mediated apoptosis pathway in rats with DE. On the whole, these results suggest that miR-130b activates the PI3K/Akt signaling pathway to exert protective effects against oxidative stress injury via the regulation of PTEN in rats with DE.

Bisphenol B stimulates Leydig cell proliferation but inhibits maturation in late pubertal rats

Bisphenol B (BPB) has been used as a substitute for bisphenol A (BPA) in plastic materials. Whether BPB disrupts the male reproductive system remains unknown. Here, we report the effect of BPB on Leydig cell maturation in late puberty. Male Sprague-Dawley (35 days old) rats were gavaged with BPB at 0, 10, 100, and 200 mg/kg/day for 21 days. BPB significantly reduced body and epididymis weight at 200 mg/kg. BPB markedly decreased serum testosterone levels at 100 and 200 mg/kg and serum luteinizing hormone and follicle-stimulating hormone levels at 200 mg/kg. BPB significantly increased Leydig cell number at 100 and 200 mg/kg, while down-regulating the expression of Leydig cell genes (Cyp11a1 and Hsd3b1) at ≥100 mg/kg and up-regulating the expression of Sertoli cell genes (Pdgfra, Fshr, Sox9) and cell cycle regulators (Pcna, Ccnb1, Cdk2, and Cdk4) at 10-200 mg/kg. BPB markedly increased the phosphorylation of AKT1, AKT2, and ERK1/2 at 200 mg/kg. BPB increased the proliferation of rat immature Leydig cells via promoting the S/M2 phase shift at 100 and 1000 nM after 24-h culture in vitro. In conclusion, BPB disrupts Leydig cell maturation in late puberty by increasing Leydig cell number while inhibiting its maturation.

Integrin β1 regulates proliferation, apoptosis, and migration of trophoblasts through activation of phosphoinositide 3 kinase/protein kinase B signaling

AIMS

Abnormal trophoblast invasion is one of the onsets of preeclampsia (PE). Studies found that integrin β1 (ITGB1) is closely related to PE, but the role of ITGB1 in the progression of trophoblast remained unclear. Therefore, we studied the functional role of ITGB1 in PE and its effects on trophoblast.

METHODS

ITGB1 expression in placenta tissues was determined by quantitative real-time polymerase chain reaction (qRT-PCR). The effects of transfection on HTR-8/SVneo cells were analyzed by qRT-PCR and western blotting. After cell transfection, colony formation assay, flow cytometry, wound healing assay, and transwell assay were performed to detect cell proliferation, apoptosis, migration, and invasion. Western blotting assay was used for determining phosphoinositide 3 kinase (PI3K) and protein kinase B (Akt) signaling pathway. After inhibiting PI3K/Akt pathway, apoptosis-regulated proteins were detected by western blotting, and the effects of inhibitor on the migration and invasion changes were examined.

RESULTS

ITGB1 was downregulated in placenta tissues from PE patients, as compared with normal. ITGB1 overexpression in HTR-8/SVneo cells enhanced cell proliferation, migration, and invasion, reduced cell apoptosis, and improved phosphorylation of PI3K and Akt. However, ITGB1 depletion resulted in an opposite effect to its overexpression. Inhibition of PI3K/Akt pathway completely blocked the effect of ITGB1 overexpression on cells, because we observed that apoptosis-regulated proteins were highly upregulated, and that cell migration and invasion were reduced.

CONCLUSION

ITGB1 regulated HTR-8/SVneo cell progression by activation of the PI3K/Akt pathway.

Protective effect of scorpion venom heat-resistant synthetic peptide against PM2.5-induced microglial polarization via TLR4-mediated autophagy activating PI3K/AKT/NF-κB signaling pathway

There is growing evidence that fine particulate matter (PM_2.5) is a considerable risk factor for neurodegenerative diseases. Scorpion venom heat-resistant synthetic peptide (SVHRSP) plays a neuroprotective effect by promoting neurogenesis and neuron axon growth. In this study, SVHRSP inhibited the level of TLR4, autophagy and PM2.5-induced microglia M1 polarization, thereby promoting Phosphorylation of PI3K and AKT, inhibiting the expression of NF-κB. Moreover, SVHRSP suppressed the cytotoxic factors and increased the cytoprotective factor. This research demonstrates that SVHRSP relieves PM_2.5-induced microglial polarization via TLR4-mediated autophagy activating PI3K/AKT/NF-κB signaling pathway, which provides new insights for the treatment of PM_2.5-induced neurodegenerative diseases.

hucMSCs transplantation promotes locomotor function recovery, reduces apoptosis and inhibits demyelination after SCI in rats

AIMS

Spinal cord injury (SCI) can cause a variety of cells apoptosis, neurodegeneration, and eventually permanent paralysis. This study aimed to examine whether transplanting human umbilical cord mesenchymal stem cells (hucMSCs) can promote locomotor function recovery, reduce apoptosis and inhibit demyelination in SCI models.

MAIN METHODS

Rats were allocated into Sham group (spinal cord exposure only), SCI + PBS group (spinal cord impact plus phosphate-buffered saline (PBS) injections), SCI + hucMSCs group (spinal cord impact plus hucMSCs injections) groups. Behavioral tests, Basso-Beattie-Bresnahan locomotion scores (BBB scores), were carried out at 0, 3, 7, 14, 21, 28 days after SCI surgery. Hematoxylin-eosin staining observed spinal cord morphology. Nissl staining detected the number of nissl bodies. Myelin basic protein (MBP) and oligodendrocyte (CNPase) were examed by immunohistochemical staining. The apoptosis of oligodendrocyte and neurons were detected by immunofluorescence.

RESULTS

The 28-day behavioral test showed that the BBB score of rats in the SCI + hucMSCs group increased significantly, comparing to the SCI + PBS group. The numbers of nissl bodies and myelin sheath in the damaged area of SCI + hucMSCs group were also significantly increased compared to the SCI + PBS group. HucMSCs transplanting decreased the expression of protein level of Caspase-3 and Bax and increased the Bcl-2, MBP and CNPase, rescued the apoptosis of neurons and the oligodendrocyte.

CONCLUSION

These results showed that hucMSCs can improve motor function, tissue repairing and reducing apoptosis in SCI rats.

Current and Future Perspectives of PD-1/PDL-1 Blockade in Cancer Immunotherapy

Cancer immunotherapy, which reactivates weakened immune cells of cancer patients, has yielded great success in recent years. Among immunotherapeutic agents, immune checkpoint inhibitors have been of particular interest and have gained approval by the FDA for treatment of cancers. Immune checkpoint blockade through targeting programmed cell death protein-1 (PD-1) has demonstrated promising antitumor effects in cancer immunotherapy of many different solid and hematologic malignancies. However, despite promising results, a favorable response is observed only in a fraction of patients, and there is still lack of a single therapy modality with curative ability. In this paper, we review the current and future perspectives of PD-1/L1 blockade in cancer immunotherapy, with a particular focus on predictive biomarkers of response to therapy. We also discuss the adverse events associated with PD-1/L1/2 inhibitors, ranging from severe life-threatening conditions such as autoimmune myocarditis to mild and moderate reactions such as skin rashes, and explore the potential strategies for improving the efficacy of immunotherapy with PD-1/L1 checkpoint inhibitors.

Review of the Efficacy and Mechanisms of Traditional Chinese Medicines as a Therapeutic Option for Ionizing Radiation Induced Damage

Ionizing radiation damage refers to acute, delayed, or chronic tissue damage associated with ionizing radiation. Specific or effective therapeutic options for systemic injuries induced by ionizing radiation have not been developed. Studies have shown that Chinese herbal Medicine or Chinese Herbal Prescription exhibit preventive properties against radiation damage. These medicines inhibit tissue injuries and promote repair with very minimal side effects. This study reviews traditional Chinese herbal medicines and prescriptions with radiation protective effects as well as their mechanisms of action. The information obtained will guide the development of alternative radioprotectants.

Chemical composition and pharmacological mechanism of ephedra-glycyrrhiza drug pair against coronavirus disease 2019 (COVID-19)

Traditional Chinese medicine (TCM) had demonstrated effectiveness in the prevention and control of COVID-19. Statistics showed that Ephedra and Glycyrrhiza were frequently used in the treatment of COVID-19. We hypothesized that the Ephedra-Glycyrrhiza drug pair is a potential choice for the treatment of COVID-19. Here, 112 active compounds were identified from Ephedra-Glycyrrhiza via network pharmacology approach. Ephedra-Glycyrrhiza pair enrichment analysis demonstrated that these compounds might participate in the cAMP, PI3K-Akt, JAK-STAT and chemokine signaling pathways, which had a high correlation with respiratory, nervous, blood circulation and digestive system-related diseases. Pathway analysis between Ephedra-Glycyrrhiza and COVID-19 showed that the key targets were TNF-α, IL2, FOS, ALB, and PTGS2. They might control PI3K-Akt signaling pathway to exert immune regulation, organ protection and antiviral effects. Molecular docking results showed that the active compounds from the Ephedra-Glycyrrhiza pair bound well to COVID-19 related targets, including the main protease (Mpro, also called 3CLpro), the spike protein (S protein), and the angiotensin-converting enzyme 2 (ACE2). The Molecular dynamics simulation was analyzed for the stability and flexibility of the complex. In conclusion, our study elucidated the potential pharmacological mechanism of Ephedra-Glycyrrhiza in the treatment of COVID-19 through multiple targets and pathways.

Cyclophilin A inhibits A549 cell oxidative stress and apoptosis by modulating the PI3K/Akt/mTOR signaling pathway

The excessive and inappropriate production of reactive oxygen species (ROS) can cause oxidative stress and is implicated in the pathogenesis of lung cancer. Cyclophilin A (CypA), a member of the immunophilin family, is secreted in response to ROS. To determine the role of CypA in oxidative stress injury, we investigated the role that CypA plays in human lung carcinoma (A549) cells. Here, we showed the protective effect of human recombinant CypA (hCypA) on hydrogen peroxide (H₂O₂)-induced oxidative damage in A549 cells, which play crucial roles in lung cancer. Our results demonstrated that hCypA substantially promoted cell viability, superoxide dismutase (SOD), glutathione (GSH), and GSH peroxidase (GSH-Px) activities, and attenuated ROS and malondialdehyde (MDA) production in H₂O₂-induced A549 cells. Compared with H₂O₂-induced A549 cells, Caspase-3 activity in hCypA-treated cells was significantly reduced. Using Western blotting, we showed that hCypA facilitated Bcl-2 expression and inhibited Bax, Caspase-3, Caspase-7, and PARP-1 expression. Furthermore, hCypA activates the PI3K/Akt/mTOR pathway in A549 cells in response to H₂O₂ stimulation. Additionally, peptidyl-prolyl isomerase activity was required for PI3K/Akt activation by CypA. The present study showed that CypA protected A549 cells from H₂O₂-induced oxidative injury and apoptosis by activating the PI3K/Akt/mTOR pathway. Thus, CypA might be a potential target for lung cancer therapy.

Low molecular weight-PAHs induced inflammation in A549 cells by activating PI3K/AKT and NF-κB signaling pathways

Our previous study has demonstrated that two low molecular weight-polycyclic aromatic hydrocarbons (LMW-PAHs), phenanthrene (Phe) and fluorene (Flu), alone and as a mixture could induce oxidative damage and inflammation in A549 cells. However, the associated mechanisms have not been well discussed. The aim of this study was to further investigate the roles of PI3K/AKT and NF-κB signaling pathways in the inflammatory effects in A549 cells induced by Phe, Flu and their mixture. The results indicated that Phe, Flu and their mixture significantly activated PI3K/AKT and NF-κB signaling pathways by increasing the phosphorylation levels of PI3K, AKT, IκBα and NF-κB p65. In addition, pro-inflammatory cytokine expressions of TNF-α and IL-6 induced by the binary mixture of Phe and Flu were all alleviated by co-treatment with PI3K/AKT and NF-κB specific inhibitors (LY294002 and BAY11-7082). The results suggested that PI3K/AKT and NF-κB signaling pathways played an important role in LMW-PAHs induced inflammation in A549 cells.

MC-LR-induced interaction between M2 macrophage and biliary epithelial cell promotes biliary epithelial cell proliferation and migration through regulating STAT3

Microcystin-leucine-arginine (MC-LR) was produced by toxic cyanobacteria, which has been shown to have potent hepatotoxicity. Our previous study has proved that MC-LR were able to promote intrahepatic biliary epithelial cell excessive proliferation. However, the underlying mechanism is not yet entirely clarified. Herein, mice were fed with different concentrations (1, 7.5, 15, or 30 μg/L) of MC-LR by drinking water for 6 months. As the concentration of MC-LR increased, a growing number of macrophages were evaluated in the portal area of the mouse liver. Next, we built a co-culture system to explore the interaction between macrophages (THP-1 cells) and human intrahepatic biliary epithelial cells (HiBECs) in the presence of MC-LR. Under the exposure of MC-LR, HiBECs secreted a large amount of inflammatory factors (IL-6, IL-8, IL-1β, COX-2, XCL-1) and chemokine (MCP-1), which produced a huge chemotactic effect on THP-1 cells and induced elevation of the surface M2-subtype biomarkers (IL-10, CD163, CCL22, and Arg-1). In turn, high content of IL-6 in the medium activated JAK2/STAT3, MEK/ERK, and PI3K/AKT pathways in HiBECs, inducing HiBEC abnormal proliferation and migration. Together, these results suggested that MC-LR-mediated interaction between HiBECs and macrophages induced the M2-type polarization of macrophages, and activated IL-6/JAK2/STAT3, MEK/ERK, and PI3K/AKT pathways in HiBECs, further enhanced cell proliferation, improved cell migration, and hindered cell apoptosis by activating p-STAT3. MC-LR stimulates HiBECs to produce various inflammatory factors, recruiting a large number of macrophages and promoting the differentiation of macrophages into M2-type. In turn, the M2 macrophages could also produce amounts of IL-6 and activate STAT3 through JAK2/STAT3, MEK/ERK, and PI3K/AKT pathways in HiBECs, resulting in the promotion of cell proliferation, inhibition of apoptosis, and enhancement of migration.

Transcriptome analysis of the Macrobrachium nipponense hepatopancreas provides insights into immunoregulation under Aeromonas veronii infection

The oriental river prawn Macrobrachium nipponense is a commercially important freshwater shrimp that is widely farmed in China. Aeromonas veronii is a conditional pathogen of farmed shrimp, which has caused huge economic losses to the industry. Therefore, there is urgency to study the host-pathogen interactions between M. nipponense and A. veronii to screen individuals with antimicrobial resistance. In this study, we examined the hepatopancreas of moribund M. nipponense infected with A. veronii and healthy individuals at both the histopathological and transcriptomic levels. We showed that A. veronii infection resulted in tubular necrosis of the M. nipponense hepatopancreas. Such changes likely affect assimilation, storage, and excretion by the hepatopancreas, which could ultimately affect the survival and growth of infected individuals. Among the 61,345 unigenes obtained through RNA sequencing and de novo transcriptome assembly, 232 were differentially expressed between the two groups. KEGG and GO analyses revealed that these differentially expressed genes were implicated in pathways, including PPAR, PI3K/AKT, and AMPK signaling. The results of this study will contribute to an analysis of the immune response of M. nipponense to A. veronii infection at the transcriptomic level. Furthermore, the RNA-seq data generated here provide an important genomic resource for research on M. nipponense in the absence of a reference genome.

Case Report: EBV Chronic Infection and Lymphoproliferation in Four APDS Patients: The Challenge of Proper Characterization, Therapy, and Follow-Up

Activated PI3K-kinase Delta Syndrome (APDS) is an autosomal-dominant primary immunodeficiency (PID) caused by the constitutive activation of the PI3Kδ kinase. The consequent hyperactivation of the PI3K-Akt-mTOR pathway leads to an impaired T- and B-cells differentiation and function, causing progressive lymphopenia, hypogammaglobulinemia and hyper IgM. Patients with APDS show recurrent sinopulmonary and chronic herpes virus infections, immune dysregulation manifestations, including cytopenia, arthritis, inflammatory enteropathy, and a predisposition to persistent non-neoplastic splenomegaly/lymphoproliferation and lymphoma. The recurrence of the lymphoproliferative disorder and the difficulties in the proper definition of malignancy on histological examination represents the main challenge in the clinical management of APDS patients, since a prompt and correct diagnosis is needed to avoid major complications. Targeted therapies with PI3Kδ-Akt-mTOR pathway pharmacologic inhibitors (i.e., Rapamycin, Theophylline, PI3K inhibitors) represent a good therapeutic strategy. They can also be used as bridge therapies when HSCT is required in order to control refractory symptoms. Indeed, treated patients showed a good tolerance, improved immunologic phenotype and reduced incidence/severity of immune dysregulation manifestations. Here, we describe our experience in the management of four patients, one male affected with APDS1 (P1) and the other three, a male and two females, with APDS2 (P2, P3, P4) presenting with chronic EBV replication, recurrent episodes of immune dysregulation manifestations and lymphomas. These cases highlighted the importance of a tailored and close follow-up, including serial endoscopic and lymph nodes biopsies control to detect a prompt and correct diagnosis and offer the best therapeutic strategy.

Regulatory effect of Zuojin Pill on correlation with gut microbiota and Treg cells in DSS-induced colitis

ETHNOPHARMACOLOGICAL RELEVANCE

As a classic prescription and commercial Chinese patent medicine, Zuojin Pill (ZJP) has been used to treat ulcerative colitis (UC) effectively for many years. However, its mechanism of action remains unclear.

AIM OF THE STUDY

METHODS: Mice with dextran-sulfate-sodium-induced colitis were treated with ZJP for 7 d. In the present study, the therapeutic effect of ZJP was evaluated by macroscopic and microscopic observation; regulatory T (Treg) cells and their subsets were analyzed by flow cytometry; and the composition of gut microbiota was tested by 16S rRNA analysis. Activation of the phosphoinostide 3-kinase (PI3K)/Akt signaling pathway was observed by western blotting.

RESULTS

The pathological damage was attenuated and expression of proinflammatory cytokines was decreased. While the diversity of intestinal microflora was regulated, the relative abundance of Actinobacteria, and Sphingobacteriia was modified. Meanwhile, the level of CD4⁺CD25⁺Foxp3⁺ and PD-L1⁺ Treg cells improved. These changes maintained a positive correlation which was analyzed statistically. Our results also showed that ZJP inhibited activation of the PI3K/Akt signaling pathway.

CONCLUSIONS

ZJP regulates crosstalk between intestinal microflora and Treg cells to attenuate experimental colitis via the PI3K/Akt signaling pathway.

Chlorpyrifos induces the apoptosis and necroptosis of L8824 cells through the ROS/PTEN/PI3K/AKT axis

Excessive chlorpyrifos (CPF) in the environment causes toxicity to nontarget organisms by triggering oxidative stress. Phosphatase and tensin homolog deleted on chromosome ten (PTEN) plays an important role in controlling apoptosis and necrosis by negatively regulating the phosphatidylinositol 3-kinase/threonine kinase (PI3K/AKT) pathway. However, the effects of different concentrations of CPF on grass fish liver cell injury and the role of the ROS/PTEN/PI3K/AKT axis remain poorly understood. In this study, L8824 cells treated with different concentrations of CPF (0, 40, 60, or 80 μM) were used as the research object. The results showed that the median inhibitory concentration (IC50) was 112.226 μM. As the CPF concentrations increased, the ROS and MDA levels increased, and the T-AOC levels and SOD/GPx/GST activities decreased. As PTEN expression increased, PI3K/AKT, BCL-2, and Caspase-8 expression dramatically decreased. Conversely, RIPK1/RIPK3/MLKL and Bax/Cyt-c/Caspase-3 expression increased. Additionally, necroptosis increased in a dose-dependent manner, while apoptosis first increased and then decreased. In conclusion, our study showed that CPF could trigger oxidative stress and induce apoptosis and necroptosis in fish liver cells by regulating the ROS/PTEN/PI3K/AKT axis, and the type of damage induced was dose-dependent. These results are meaningful for toxicological studies of CPF and efforts to protect the ecosystem.

'Nur'turing tumor T cell tolerance and exhaustion: novel function for Nuclear Receptor Nur77 in immunity

The nuclear receptor Nur77 is expressed in a multitude of tissues, regulating cell differentiation and homeostasis. Dysregulation of Nur77 signaling is associated with cancer, cardiovascular disease, and disorders of the CNS. The role of Nur77 in T cells has been studied for almost 30 years now. There is a clear appreciation that Nur77 is crucial for apoptosis of self‐reactive T cells. However, the regulation and function of Nur77 in mature T cells remains largely unclear. In an exciting development, Nur77 has been recently demonstrated to impinge on cancer immunotherapy involving chimeric antigen receptor (CAR) T cells and tumor infiltrating lymphocytes (TILs). These studies indicated that Nur77 deficiency reduced T cell tolerance and exhaustion, thus raising the effectiveness of immune therapy in mice. Based on these novel insights, it may be proposed that regulation of Nur77 activity holds promise for innovative drug development in the field of cellular immunotherapy in cancer. In this review, we therefore summarize the role of Nur77 in T cell selection and maturation; and further develop the idea of targeting its activity in these cells as a potential strategy to augment current cancer immunotherapy treatments.

CD226 Attenuates Treg Proliferation via Akt and Erk Signaling in an EAE Model

Cluster of differentiation 226 (CD226) molecules play a crucial role in the activation of effector CD4⁺ T cells during the immune response process, but a cell-intrinsic function of CD226 in CD4⁺ T subsets is not clear. In this study, we showed that Cd226^−/− mice were resistant to myelin oligodendrocyte glycoprotein peptide 35-55 (MOG₃₅₋₅₅)-induced experimental autoimmune encephalomyelitis (EAE) with highly expressed IL-10⁺CD4⁺ T cells and downregulated IL-17A⁺CD4⁺ T cells when compared with wild-type (WT) mice. Th17 cell infiltration into the central nervous system (CNS) was largely decreased in the absence of CD226 during EAE. CD226 deficiency facilitated the proliferation of regulatory T cells (Tregs), with increased numbers of Tregs observed in EAE mice, and supported the elevated induced regulatory T cell (iTregs) proliferation in vitro. The Akt and Erk signaling pathways were shown to be involved in Cd226^−/− Treg proliferation and function in vivo and in vitro. These findings collectively indicate that CD226 is a key molecule regulating the Treg-mediated suppression of autoimmune responses by inhibiting Treg proliferation. Thus, the results of this study identify additional mechanisms by which CD226 regulates Treg functions in EAE and supports the potential therapeutic effects of anti-CD226 molecules on autoimmune diseases.

Sustaining Circulating Regulatory T Cell Subset Contributes to the Therapeutic Effect of Paroxetine on Mice With Diabetic Cardiomyopathy

BACKGROUND

G protein coupled receptor kinase 2 (GRK2) inhibitor, paroxetine, has been approved to ameliorate diabetic cardiomyopathy (DCM). GRK2 is also involved in regulating T cell functions; the potential modifications of paroxetine on the immune response to DCM is unclear.Methods and Results:DCM mouse was induced by high-fat diet (HFD) feeding. A remarkable reduction in the regulatory T (Treg) cell subset in DCM mouse was found by flow cytometry, with impaired cardiac function evaluated by echocardiography. The inhibited Treg differentiation was attributable to insulin chronic stimulation in a GRK2-PI3K-Akt signaling-dependent manner. The selective GRK2 inhibitor, paroxetine, rescued Treg differentiation in vitro and in vivo. Furthermore, heart function, as well as the activation of excitation-contraction coupling proteins such as phospholamban (PLB) and troponin I (TnI) was effectively promoted in paroxetine-treated DCM mice compared with vehicle-treated DCM mice. Blockade of FoxP3 expression sufficiently inhibited the proportion of Treg cells, abolished the protective effect of paroxetine on heart function as well as PLB and TnI activation in HFD-fed mice. Neither paroxetine nor carvedilol could effectively ameliorate the metabolic disorder of HFD mice.

CONCLUSIONS

The impaired systolic heart function of DCM mice was effectively improved by paroxetine therapy, partially through restoring the population of circulating Treg cells by targeting the GRK2-PI3K-Akt pathway.

Effect of Sishen Pill on Memory T Cells From Experimental Colitis Induced by Dextran Sulfate Sodium

Immune memory has a protective effect on the human body, but abnormal immune memory is closely related to the occurrence and development of autoimmune diseases including inflammatory bowel disease (IBD). Sishen Pill (SSP) is a classic prescription of traditional Chinese medicine, which is often used to treat chronic colitis, but it is not clear whether SSP can alleviate experimental colitis by remodeling immune memory. In the present study, the therapeutic effect of SSP on chronic colitis induced by dextran sulfate sodium (DSS) was evaluated by colonic length, colonic weight index, macroscopic and microscopic scores, and pathological observation. The cytokine levels were tested by enzyme-linked immunosorbent assay (ELISA); the percentages of central memory T (Tcm) and effector memory T (Tem) cells were analyze\d by flow cytometry; and activation of phosphoinositide 3-kinase (PI3K)/Akt signaling proteins was measured by western blotting. After 7-days' treatment, SSP alleviated DSS-induced colitis, which was demonstrated by decreased colonic weight index, colonic weight, histopathological injury scores, restored colonic length, gradual recovery of colonic mucosa, and lower levels of interleukin (IL)-2, IL-7, IL-12, and IL-15, while SSP increased IL-10 expression. SSP obviously regulated the quantity and subpopulation of Tcm and Tem cells. Furthermore, SSP markedly inhibited activation of PI3K, Akt, phospho-Akt, Id2, T-bet, forkhead box O3a, Noxa, and C-myc proteins in the PI3K/Akt signaling pathway and activated Rictor, Raptor, tuberous sclerosis complex (TSC)1, TSC2, phospho-AMP-activated kinase (AMPK)-α, AMPK-α, eukaryotic translation initiation factor 4E-binding protein 2, kinesin family member 2a, and 70-kDa ribosomal protein S6 kinase. These results indicate that SSP effectively controls Tem cells in the peripheral blood to relieve experimental colitis induced by DSS, which were potentially related with inhibiting the PI3K/Akt signaling pathway.

Loss of Phosphatidylinositol 3-Kinase Activity in Regulatory T Cells Leads to Neuronal Inflammation

Class I PI3K enzymes are critical for the maintenance of effective immunity. In T cells, PI3Kα and PI3Kδ are activated by the TCR and costimulatory receptors, whereas PI3Kγ is activated by G protein-coupled chemokine receptors. PI3Kδ is a key regulator of regulatory T (Treg) cell function. PI3K isoform-selective inhibitors are in development for the treatment of diseases associated with immune dysregulation, including chronic inflammatory conditions, cancer, and autoimmune diseases. Idelalisib (PI3Kδ), alpelisib (PI3Kα), duvelisib (PI3Kδ/γ), and copanlisib (pan-PI3K) have recently been approved for use in cancer treatment. Although effective, these therapies often have severe side effects associated with immune dysregulation and, in particular, loss of Treg cells. Therefore, it is important to gain a better understanding of the relative contribution of different PI3K isoforms under homeostatic and inflammatory conditions. Experimental autoimmune encephalitis is a mouse model of T cell-driven CNS inflammation, in which Treg cells play a key protective role. In this study, we show that PI3Kδ is required to maintain normal Treg cell development and phenotype under homeostatic conditions but that loss of PI3Kδ alone in Treg cells does not lead to autoimmunity. However, combined loss of PI3Kα and PI3Kδ signaling resulted in increased experimental autoimmune encephalitis disease severity. Moreover, mice lacking PI3Kα and PI3Kδ in Treg cells developed spontaneous peripheral nerve inflammation. These results show a key role for PI3K signaling in Treg cell-mediated protection against CNS inflammation.

Recombinant Human Brain Natriuretic Peptide Attenuates Myocardial Ischemia-Reperfusion Injury by Inhibiting CD4+ T Cell Proliferation via PI3K/AKT/mTOR Pathway Activation

Inflammation plays a major role in the development of myocardial ischemia-reperfusion (IR) injury. Recombinant human brain natriuretic peptide (rhBNP), a man-made version of a peptide that is elevated in heart failure, exhibits anti-inflammatory effects in various tissues. However, its role in myocardial IR injury remains unclear. In this study, we demonstrate that treatment with rhBNP provided protection for mice against myocardial IR injury as manifested by reduced infarct size and well-preserved myocardial, attenuated inflammatory infiltration and CD4⁺ T cell proliferation function, and inhibited expression of proinflammatory related genes. Furthermore, mechanistic studies revealed that rhBNP inhibited Jurkat T proliferation by promoting PI3K/AKT/mTOR phosphorylation. Collectively, our data suggest that the administration of rhBNP during IR injury could expand our understanding of the cardioprotective effects of rhBNP.

Development of PLGA-PEG-PLGA Hydrogel Delivery System for Enhanced Immunoreaction and Efficacy of Newcastle Disease Virus DNA Vaccine

The highly contagious Newcastle disease virus (NDV) continues to threaten poultry all over the world. The NDV DNA vaccine is a promising solution to the current Newcastle disease (ND) challenges, and thus an efficient delivery system should be developed to facilitate the efficacy of DNA vaccines. In this study, we developed a DNA vaccine delivery system consisting of a triblock copolymer of poly(lactide co-glycolide acid) and polyethylene glycol (PLGA-PEG-PLGA) hydrogel in which the recombinant NDV hemagglutinin-neuraminidase (HN) plasmid was encapsulated. Its characteristics, security, immune responses, and efficacy against highly virulent NDV were detected. The results showed that the plasmids were gradually released in a sustained manner from the hydrogel, which improved the biological stability of the plasmids and demonstrated a high biocompatibility. The plasmids, when they were incorporated into the hydrogel delivery system, enhanced immune activation and provided 100% protection against the highly virulent NDV strain. Furthermore, we proved that this NDV DNA hydrogel vaccine could improve the lymphocyte proliferation and increase the immunological cytokine production via the PI3K/Akt pathway. These results indicate that the PLGA-PEG-PLGA thermosensitive hydrogel could be a promising delivery system for the NDV DNA vaccine in order to achieve a sustained supply of plasmids and induce potent immune responses.

Exploring the controversial role of PI3K signalling in CD4+ regulatory T (T-Reg) cells

The immune system is a complex network that acts to protect vertebrates from foreign microorganisms and carries out immunosurveillance to combat cancer. In order to avoid hyper-activation of the immune system leading to collateral damage tissues and organs and to prevent self-attack, the network has the intrinsic control mechanisms that negatively regulate immune responses. Central to this negative regulation are regulatory T (T-Reg) cells, which through cytokine secretion and cell interaction limit uncontrolled clonal expansion and functions of activated immune cells. Given that positive or negative manipulation of T-Regs activity could be utilised to therapeutically treat host versus graft rejection or cancer respectively, understanding how signaling pathways impact on T-Regs function should reveal potential targets with which to intervene. The phosphatidylinositol-3-kinase (PI3K) pathway controls a vast array of cellular processes and is critical in T cell activation. Here we focus on phosphoinositide 3-kinases (PI3Ks) and their ability to regulate T-Regs cell differentiation and function.

Modulation of regulatory T cell function and stability by co-inhibitory receptors

Regulatory T (T_reg) cells constitute a dynamic population that is essential for controlling immune responses in health and disease. Defects in T_reg cell function and decreases in T_reg cell numbers have been observed in patients with autoimmunity and the opposite effects on T_reg cells occur in cancer settings. Current research on new therapies for these diseases is focused on modulating T_reg cell function to increase or decrease suppressive activity in autoimmunity and cancer, respectively. In this regard, several co-inhibitory receptors that are preferentially expressed by T_reg cells under homeostatic conditions have recently been shown to control T_reg cell function and stability in different disease settings. These receptors could be amenable to therapeutic targeting aimed at modulating T_reg cell function and plasticity. This Review summarizes recent data regarding the role of co-inhibitory molecules in the control of T_reg cell function and stability, with a focus on their roles and potential therapeutic use in autoimmunity and cancer.

Ex vivo expansion of regulatory T cells from long-term Belatacept-treated kidney transplant patients restores their phenotype and suppressive function but not their FOXP3 TSDR demethylation status

We recently reported that Tregs from long-term Belatacept-treated kidney transplant patients displayed an altered phenotype and impaired suppressive function compared to Tregs from healthy controls. However, it remains unknown whether ex vivo expansion of Tregs from patients who underwent long-term immunosuppression may be feasible to be used in their treatment. In this work, Tregs from Belatacept-treated patients were polyclonally expanded in vitro in the presence of rapamycin and IL-2. After four weeks of expansion, Tregs from patients expressed high levels of FOXP3, CD25, CTLA-4, Helios and CCR7, and showed strong suppressive activity, even in the presence of pro-inflammatory cytokines. However, FOXP3 TSDR demethylation remained lower in expanded Tregs from Belatacept-treated patients compared to healthy control Tregs. These data suggest that ex vivo expansion of Tregs from patients undergoing long-term immunosuppression may require the use of epigenetic modifying agents to stabilize FOXP3 expression to be considered as treatment in kidney transplant patients.