Effect of miR-1297 on Kidney Injury in Rats with Diabetic Nephropathy through the PTEN/PI3K/AKT Pathway

PURPOSE

This study aimed to determine the influence of miR-1297 on kidney injury in rats with diabetic nephropathy (DN) and its causal role.

METHODS

A DN rat model was established through right kidney resection and intraperitoneal injection of streptozotocin (STZ). Sham rats did not undergo right kidney resection or STZ injection. The DN rats were divided into the DN model and antagomiR-1297 treatment groups. Kidney morphology was observed using hematoxylin and eosin staining. Renal function indices, including blood urea nitrogen (BUN), serum creatinine (SCr), and urinary protein, were measured using kits. Levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were determined through enzyme-linked immunosorbent assay (ELISA). Fibrin (FN), collagen type I (Col I), and α-smooth muscle actin (α-SMA) were assessed through western blotting and real-time reverse transcription-polymerase chain reaction. Apoptosis was detected using terminal deoxynucleotidyl transferase dUTP nick end labeling staining. miR-1297 targets were predicted using bioinformatic software and verified through luciferase reporter assay. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN)/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway expression was analyzed through western blotting.

RESULTS

AntagomiR-1297 reduced BUN (p = 0.005), SCr (p = 0.012), and urine protein (p < 0.001) levels and improved kidney tissue morphology. It prevented renal interstitial fibrosis by decreasing FN, Col I, and α-SMA protein levels (all p < 0.001). AntagomiR-1297 increased SOD (p = 0.001) and GSH-Px (p = 0.002) levels. Additionally, it reduced levels of cell inflammatory factors, including TNF-α, IL-6, and IL-1β (all p < 0.001), and alleviated apoptosis (p < 0.001) in rat kidney tissue with DN. miR-1297 was pinpointed as a target for PTEN. AntagomiR-1297 increased PTEN expression and suppressed PI3K and AKT phosphorylation (all p < 0.001).

CONCLUSIONS

AntagomiR-1297 can mitigate renal fibrosis, renal inflammation, apoptosis, and oxidative stress levels through the PTEN/PI3K/AKT pathway.

IRS1 promotes thyroid cancer metastasis through EMT and PI3K/AKT pathways

OBJECTIVE

Insulin receptor substract 1 (IRS1) protein is an important signal transduction adapter for extracellular signal transduction from insulin-like growth factor-1 receptor and its family members to IRS1 downstream proteins. IRS1 has been reported to be involved in tumourigenesis and metastasis in some of solid tumors. Investigating the role of IRS1 in thyroid cancer can help to screen high risk patients at the initial diagnosis.

DESIGN, PATIENTS AND MEASUREMENTS

Immunohistochemical assay was used to detect the expression levels of IRS1 in 131 metastatic thyroid cancer tissues. Wound healing, cell invasion and colony formation assays were used to study the functions of IRS1 in vitro. RNA sequencing (RNA-seq) and Western blot analysis analyses were performed to examine the underlying regulation mechanisms of IRS1 in thyroid cancer cells.

RESULTS

IRS1 was highly expressed in thyroid cancers and its expression was positively associated with distant metastasis and advanced clinical stages. In vitro studies demonstrated that IRS1 is an important mediator of migration, invasion and colony formation of thyroid cancer cells. RNA-seq showed that IRS1 promoted the metastasis of thyroid cancer by regulating epithelial-mesenchymal transition and phosphoinositide 3-kinase (PI3K)/AKT pathway.

CONCLUSIONS

IRS1 overexpression contributes to the aggressiveness of thyroid cancer and is expected to be a stratified marker and a potential therapeutic target for thyroid cancer.

Kinetochore scaffold 1 downregulation suppressed the development of non-small cell lung cancer by inactivating the phosphatidylinositol 3 kinase/protein kinase B (AKT)/nuclear factor-kappa B pathway

Kinetochore scaffold 1 (KNL1) is indispensable for generating motile micro-tubule attachments and isolating chromosomes. KNL1 is highly expressed in multiple middle-route tissues and promotes tumor development. However, how it functions in non-small cell lung cancer (NSCLC) is unclear. Real-time quantitative PCR (RT-qPCR) and Western blotting (WB) were used to determine KNL1 expression in NSCLC tissues and cells. The sh-KNL1 or oe-KNL1 was transfected into NSCLC cells. The colony formation assay, cell counting kit-8 (CCK-8) assay, and flow cytometry were used to evaluate cell proliferation and apoptosis. A transwell assay was used to monitor invasion and migration. The CCK-8 assay was used to measure NSCLC cell sensitivity to chemotherapy drugs. WB confirmed the protein levels of apoptosis-related proteins, cell cycle-associated proteins, and the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/nuclear factor kappaB (NF-κB) pathway. A PI3K/AKT/NF-κB pathway inhibitor was used to intervene in NSCLC cell transfection along with oe-KNL1, thus revealing the function of the pathway in carcinogenicity mediated by KNL1. In result KNL1 expression was substantially increased in NSCLC tissues and cells. High-level KNL1 expression is related to the poor prognosis of NSCLC patients. KNL1 silencing bolstered promoted NSCLC cell apoptosis and inhibited proliferation, cell cycle progression, invasion, and EMT, whereas KNL1 silencing had the opposite effect. KNL1 knockdown increased NSCLC cell sensitivity to chemical drugs. KNL1 promoted PI3K/AKT/NF-κB pathway activation, while PI3K/AKT/NF-κB pathway inhibition weakened the procancer effect mediated by KNL1 overexpression but had little influence on KNL1 levels. We conclude that KNL1 activates the PI3K/AKT/NF-κB pathway to increase NSCLC progression and attenuate NSCLC sensitivity to chemotherapy drugs.

Activated phosphoinositide 3-kinase δ syndrome caused by PIK3CD mutations: expanding the phenotype

BACKGROUND

Germline heterozygous gain-of-function (GOF) mutations in the PIK3CD gene lead to a rare primary immunodeficiency disease known as activated phosphoinositide 3-kinase (PI3K) δ syndrome type 1(APDS1). Affected patients present a spectrum of clinical manifestations, particularly recurrent respiratory infections and lymphoproliferation, increased levels of serum immunoglobulin (Ig) M, Epstein-Barr virus (EBV) and cytomegalovirus (CMV) viremia. Due to highly heterogeneous phenotypes of APDS1, it is very likely that suspected cases may be misdiagnosed.

METHODS

Herein we reported three patients with different clinical presentations but harboring pathogenic variants in PIK3CD gene detected by trio whole-exome sequencing (trio-WES) and confirmed by subsequent Sanger sequencing.

RESULTS

Two heterozygous mutations (c.3061G > A, p.E1021K and c.1574 A > G, p.E525G) in PIK3CD (NM_005026.3) were identified by whole exome sequencing (WES) in the three patients. One of two patients with the mutation (c.3061G > A) presented with abdominal pain and diarrhea as the first symptoms, which was due to intussusception caused by multiple polyps of colon. The patient with mutation (c.1574 A > G) had an anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)-like clinical manifestations, including multisystemic inflammation, acute nephritic syndrome, and positive perinuclear ANCA (p-ANCA), thus the diagnosis of ANCA-AAV was considered.

CONCLUSIONS

Our study expands the spectrums of clinical phenotype and genotype of APDS, and demonstrates that WES has a high molecular diagnostic yield for patients with immunodeficiency related symptoms, such as respiratory infections, multiple ecchymosis, ANCA-associated vasculitis, multiple ileocecal polyps, hepatosplenomegaly, and lymphoid hyperplasia.

TRIAL REGISTRATION

Retrospectively registered.

Systematic review of mortality and survival rates for APDS

Activated phosphoinositide 3-kinase delta syndrome (APDS) is a rare genetic disorder that presents clinically as a primary immunodeficiency. Clinical presentation of APDS includes severe, recurrent infections, lymphoproliferation, lymphoma, and other cancers, autoimmunity and enteropathy. Autosomal dominant variants in two independent genes have been demonstrated to cause APDS. Pathogenic variants in PIK3CD and PIK3R1, both of which encode components of the PI3-kinase, have been identified in subjects with APDS. APDS1 is caused by gain of function variants in the PIK3CD gene, while loss of function variants in PIK3R1 have been reported to cause APDS2. We conducted a review of the medical literature and identified 256 individuals who had a molecular diagnosis for APDS as well as age at last report; 193 individuals with APDS1 and 63 with APDS2. Despite available treatments, survival for individuals with APDS appears to be shortened from the average lifespan. A Kaplan-Meier survival analysis for APDS showed the conditional survival rate at the age of 20 years was 87%, age of 30 years was 74%, and ages of 40 and 50 years were 68%. Review of causes of death showed that the most common cause of death was lymphoma, followed by complications from HSCT. The overall mortality rate for HSCT in APDS1 and APDS2 cases was 15.6%, while the mortality rate for lymphoma was 47.6%. This survival and mortality data illustrate that new treatments are needed to mitigate the risk of death from lymphoma and other cancers as well as infection. These analyses based on real-world evidence gathered from the medical literature comprise the largest study of survival and mortality for APDS to date.

Facial infiltrating lipomatosis with hemimegalencephaly and lymphatic malformations caused by nonhotspot phosphatidylinositol 3-kinase catalytic subunit alpha mutation

We report an unusual case of facial infiltrating lipomatosis with hemimegalencephaly and lymphatic malformations. In addition to the clinical data and imaging findings, detection of a heterozygous PIK3CA nonhotspot known pathogenic variant C420R in a facial epidermal nevus provided novel insight into the pathogenic effect of somatic PIK3CA mutations.

Activated phosphoinositide 3-kinase δ syndrome: Update from the ESID Registry and comparison with other autoimmune-lymphoproliferative inborn errors of immunity

BACKGROUND

Activated phosphoinositide-3-kinase δ syndrome (APDS) is an inborn error of immunity (IEI) with infection susceptibility and immune dysregulation, clinically overlapping with other conditions. Management depends on disease evolution, but predictors of severe disease are lacking.

OBJECTIVES

This study sought to report the extended spectrum of disease manifestations in APDS1 versus APDS2; compare these to CTLA4 deficiency, NFKB1 deficiency, and STAT3 gain-of-function (GOF) disease; and identify predictors of severity in APDS.

METHODS

Data was collected from the ESID (European Society for Immunodeficiencies)-APDS registry and was compared with published cohorts of the other IEIs.

RESULTS

The analysis of 170 patients with APDS outlines high penetrance and early onset of APDS compared to the other IEIs. The large clinical heterogeneity even in individuals with the same PIK3CD variant E1021K illustrates how poorly the genotype predicts the disease phenotype and course. The high clinical overlap between APDS and the other investigated IEIs suggests relevant pathophysiological convergence of the affected pathways. Preferentially affected organ systems indicate specific pathophysiology: bronchiectasis is typical of APDS1; interstitial lung disease and enteropathy are more common in STAT3 GOF and CTLA4 deficiency. Endocrinopathies are most frequent in STAT3 GOF, but growth impairment is also common, particularly in APDS2. Early clinical presentation is a risk factor for severe disease in APDS.

CONCLUSIONS

APDS illustrates how a single genetic variant can result in a diverse autoimmune-lymphoproliferative phenotype. Overlap with other IEIs is substantial. Some specific features distinguish APDS1 from APDS2. Early onset is a risk factor for severe disease course calling for specific treatment studies in younger patients.

SPAG5 promotes the proliferation, migration, invasion, and epithelial-mesenchymal transformation of colorectal cancer cells by activating the PI3K/AKT signaling pathway

Colorectal cancer (CRC) is a cancer that occurs in the rectum or colon with a high incidence. Sperm-associated antigen 5 (SPAG5), a gene that regulates cell division, has been observed highly expressed in a variety of cancers, but its role in CRC is unclear. This study aimed to investigate the regulatory role of SPAG5 in CRC. The expression of SPAG5 in multiple cancers and normal tissues was predicted by The Cancer Genome Atlas and Tumor Immune Estimation Resource, and the expression of SPAG5 in human normal intestinal epithelial cells NCM460 and human CRC cell lines Caco2, HT29, SW480, and LOVO was verified by western blotting (WB). The effects of silencing SPAG5 on cell viability, proliferation, and apoptosis were then investigated by cell counting kit-8, WB, and flow cytometry. The effects of silencing SPAG5 on cell migration and invasion were investigated by scratch assay and transwell assay. Finally, the phosphorylation levels of phosphoinositide 3-kinase (PI3K) and AKT in cells were detected by WB. The results showed that SPAG5 was highly expressed in CRC and was verified by WB. Silencing of SPAG5 inhibited cell viability and proliferation and increased the cell apoptosis rate. Furthermore, both cell invasion and migration abilities were suppressed by the low expression of SPAG5. Finally, WB results found that the phosphorylation levels of PI3K and AKT were reduced after SPAG5 silencing. In summary, the results showed that SPAG5 can promote the proliferation and invasion of CRC cells by targeting the PI3K/AKT signaling pathway.

BYL719 reverses gefitinib-resistance induced by PI3K/AKT activation in non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation often obtain de novo resistance or develop secondary resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs), which restricts the clinical benefit for the patients. The activation of phosphatidylinositol 3-kinase (PI3K)/AKT signal pathway is one of the most important mechanisms for the EGFR-TKIs resistance beyond T790M mutation. There are currently no drugs simultaneously targeting EGFR and PI3K signal pathways, and combination of these two pathway inhibitors may be a possible strategy to reverse theses resistances. To test whether this combinational strategy works, we investigated the therapeutic effects and mechanisms of combining BYL719, a PI3Kα inhibitor, with gefitinib, an EGFR-TKI inhibitor in EGFR-TKIs resistance NSCLC models induced by PI3K/AKT activation. Our results demonstrated that PIK3CA mutated cells showed increased growth rate and less sensitive or even resistant to gefitinib, associated with increased PI3K/AKT expression. The combination of BYL719 and gefitinib resulted in synergistic effect compared with the single agents alone in EGFR-mutated NSCLC cells with PI3K/AKT activation. The inhibition of AKT phosphorylation by BYL719 increased the antitumor efficacy of gefitinib in these cell lines. Moreover, the combined effect and mechanism of gefitinib and BYL719 were also confirmed in the NSCLC cells and patient-derived organoids under 3D culture condition, as well as in vivo. Taken together, the data indicate that PIK3CA mutation induces more aggressive growth and gefitinib resistance in NSCLC cells, and the combination treatment with gefitinib and BYL719 is a promising therapeutic approach to overcoming EGFR-TKIs resistance induced by PI3K/AKT activation.

Immunodeficiency due to a novel variant in PIK3CD: a case report

BACKGROUND

Primary immunodeficiencies are immunological disorders caused by gene mutations involved in immune system development and activation. Recently, activated phosphoinositide 3-kinase delta syndrome (APDS) due to mutations in the phosphoinositide 3-kinase (PI3K), phosphatidylinositol-4, 5-bisphosphate 3-kinase, catalytic subunit delta gene (PIK3CD), and phosphoinositide 3-kinase regulatory subunit 1 (PIK3R1) genes have been reported to induce a combined immunodeficiency syndrome leading to senescent T cells, lymphadenopathy, and immunodeficiency. The exact diagnosis of these deficiencies is essential for treatment and prognosis. In recent years, targeted treatment with selective PI3Kd inhibitors has had a significant effect on controlling the symptoms of these patients.

CASE PRESENTATION

In this case report, we represent a 27-month-old girl with recurrent fever, an increased level of inflammatory markers, and erythema nodosum, who was referred to the rheumatology clinic. In the course of evaluations, because of the lack of clinical improvement with usual treatments, and a history of frequent respiratory infections, combined immunodeficiency was diagnosed in the immunological investigations. Moreover, whole-exome sequencing was performed for her.

CONCLUSION

The genetic analysis found a novel variant of PIK3CD (c.1429 G > A) in the patient. Following daily antibiotic prophylaxis and monthly IV therapy, the patient's frequent infections and fevers were controlled.

Molecular mechanism analysis of m6A modification-related lncRNA-miRNA-mRNA network in regulating autophagy in acute pancreatitis

This study aims to explore the molecular mechanism of N6-methyladenosine (m6A) modification-related long noncoding RNA (lncRNA)-microRNA (miRNA)-messenger RNA (mRNA) network in regulating autophagy and affecting the occurrence and development of acute pancreatitis (AP). RNA-seq datasets related to AP were obtained from Gene Expression Omnibus (GEO) database and merged after batch effect removal. lncRNAs significantly related to m6A in AP, namely candidate lncRNA, were screened by correlation analysis and differential expression analysis. In addition, candidate autophagy genes were screened through the multiple databases. Furthermore, the key pathways for autophagy to play a role in AP were determined by functional enrichment analysis. Finally, we predicted the miRNAs binding to genes and lncRNAs through TargetScan, miRDB and DIANA TOOLS databases and constructed two types of lncRNA-miRNA-mRNA regulatory networks mediated by upregulated and downregulated lncRNAs in AP. Nine lncRNAs related to m6A were differentially expressed in AP, and 21 candidate autophagy genes were obtained. Phosphoinositide 3-kinase (PI3K)-Akt signaling pathway and Forkhead box O (FoxO) signaling pathway might be the key pathways for autophagy to play a role in AP. Finally, we constructed a lncRNA-miRNA-mRNA regulatory network. An upregulated lncRNA competitively binds to 13 miRNAs to regulate 6 autophagy genes, and a lncRNA-miRNA-mRNA regulatory network in which 2 downregulated lncRNAs competitively bind to 7 miRNAs to regulate 2 autophagy genes. m6A modification-related lncRNA Pvt1, lncRNA Meg3 and lncRNA AW112010 may mediate the lncRNA-miRNA-mRNA network, thereby regulating autophagy to affect the development of AP.

Chronic lithium treatment ameliorates ketamine-induced mania-like behavior via the PI3K-AKT signaling pathway

Ketamine, a rapid-acting antidepressant drug, has been used to treat major depressive disorder and bipolar disorder (BD). Recent studies have shown that ketamine may increase the potential risk of treatment-induced mania in patients. Ketamine has also been applied to establish animal models of mania. At present, however, the underlying mechanism is still unclear. In the current study, we found that chronic lithium exposure attenuated ketamine-induced mania-like behavior and c-Fos expression in the medial prefrontal cortex (mPFC) of adult male mice. Transcriptome sequencing was performed to determine the effect of lithium administration on the transcriptome of the PFC in ketamine-treated mice, showing inactivation of the phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway. Pharmacological inhibition of AKT signaling by MK2206 (40 mg/kg), a selective AKT inhibitor, reversed ketamine-induced mania. Furthermore, selective knockdown of AKT via AAV-AKT-shRNA-EGFP in the mPFC also reversed ketamine-induced mania-like behavior. Importantly, pharmacological activation of AKT signaling by SC79 (40 mg/kg), an AKT activator, contributed to mania in low-dose ketamine-treated mice. Inhibition of PI3K signaling by LY294002 (25 mg/kg), a specific PI3K inhibitor, reversed the mania-like behavior in ketamine-treated mice. However, pharmacological inhibition of mammalian target of rapamycin (mTOR) signaling with rapamycin (10 mg/kg), a specific mTOR inhibitor, had no effect on ketamine-induced mania-like behavior. These results suggest that chronic lithium treatment ameliorates ketamine-induced mania-like behavior via the PI3K-AKT signaling pathway, which may be a novel target for the development of BD treatment.

Up-regulation of the PI3K/AKT and RHO/RAC/PAK signalling pathways in CHK1 inhibitor resistant Eµ-Myc lymphoma cells

The development of resistance and the activation of bypass pathway signalling represents a major problem for the clinical application of protein kinase inhibitors. While investigating the effect of either a c-Rel deletion or RelAT505A phosphosite knockin on the Eµ-Myc mouse model of B-cell lymphoma, we discovered that both NF-κB subunit mutations resulted in CHK1 inhibitor resistance, arising from either loss or alteration of CHK1 activity, respectively. However, since Eµ-Myc lymphomas depend on CHK1 activity to cope with high levels of DNA replication stress and consequent genomic instability, it was not clear how these mutant NF-κB subunit lymphomas were able to survive. To understand these survival mechanisms and to identify potential compensatory bypass signalling pathways in these lymphomas, we applied a multi-omics strategy. With c-Rel-/- Eµ-Myc lymphomas we observed high levels of Phosphatidyl-inositol 3-kinase (PI3K) and AKT pathway activation. Moreover, treatment with the PI3K inhibitor Pictilisib (GDC-0941) selectively inhibited the growth of reimplanted c-Rel-/- and RelAT505A, but not wild type (WT) Eµ-Myc lymphomas. We also observed up-regulation of a RHO/RAC pathway gene expression signature in both Eµ-Myc NF-κB subunit mutation models. Further investigation demonstrated activation of the RHO/RAC effector p21-activated kinase (PAK) 2. Here, the PAK inhibitor, PF-3758309 successfully overcame resistance of RelAT505A but not WT lymphomas. These findings demonstrate that up-regulation of multiple bypass pathways occurs in CHK1 inhibitor resistant Eµ-Myc lymphomas. Consequently, drugs targeting these pathways could potentially be used as either second line or combinatorial therapies to aid the successful clinical application of CHK1 inhibitors.

Double Deletion of PI3K and PTEN Modifies Lens Postnatal Growth and Homeostasis

We have previously shown that the conditional deletion of either the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K), or its opposing phosphatase, phosphatase and tensin homolog (PTEN), had distinct effects on lens growth and homeostasis. The deletion of p110α reduced the levels of phosphorylated Akt and equatorial epithelial cell proliferation, and resulted in smaller transparent lenses in adult mice. The deletion of PTEN increased levels of phosphorylated Akt, altered lens sodium transport, and caused lens rupture and cataract. Here, we have generated conditional p110α/PTEN double-knockout mice, and evaluated epithelial cell proliferation and lens homeostasis. The double deletion of p110α and PTEN rescued the defect in lens size seen after the single knockout of p110α, but accelerated the lens rupture phenotype seen in PTEN single-knockout mice. Levels of phosphorylated Akt in double-knockout lenses were significantly higher than in wild-type lenses, but not as elevated as those reported for PTEN single-knockout lenses. These results showed that the double deletion of the p110α catalytic subunit of PI3K and its opposing phosphatase, PTEN, exacerbated the rupture defect seen in the single PTEN knockout and alleviated the growth defect observed in the single p110α knockout. Thus, the integrity of the PI3K signaling pathway was absolutely essential for proper lens homeostasis, but not for lens growth.

miR-579-3p Controls Hepatocellular Carcinoma Formation by Regulating the Phosphoinositide 3-Kinase-Protein Kinase B Pathway in Chronically Inflamed Liver

Chronic liver inflammation causes continuous liver damage with progressive liver fibrosis and cirrhosis, which may eventually lead to hepatocellular carcinoma (HCC). Whereas the 10-year incidence for HCC in patients with cirrhosis is approximately 20%, many of these patients remain tumor free for their entire lives. Clarifying the mechanisms that define the various outcomes of chronic liver inflammation is a key aspect in HCC research. In addition to a wide variety of contributing factors, microRNAs (miRNAs) have also been shown to be engaged in promoting liver cancer. Therefore, we wanted to characterize miRNAs that are involved in the development of HCC, and we designed a longitudinal study with formalin-fixed and paraffin-embedded liver biopsy samples from several pathology institutes from Switzerland. We examined the miRNA expression by nCounterNanostring technology in matched nontumoral liver tissue from patients developing HCC (n = 23) before and after HCC formation in the same patient. Patients with cirrhosis (n = 26) remaining tumor free within a similar time frame served as a control cohort. Comparison of the two cohorts revealed that liver tissue from patients developing HCC displayed a down-regulation of miR-579-3p as an early step in HCC development, which was further confirmed in a validation cohort. Correlation with messenger RNA expression profiles further revealed that miR-579-3p directly attenuated phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) expression and consequently protein kinase B (AKT) and phosphorylated AKT. In vitro experiments and the use of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology confirmed that miR-579-3p controlled cell proliferation and cell migration of liver cancer cell lines. Conclusion: Liver tissues from patients developing HCC revealed changes in miRNA expression. miR-579-3p was identified as a novel tumor suppressor regulating phosphoinositide 3-kinase-AKT signaling at the early stages of HCC development.

Spheroidization of ultrasonic degraded corn silk polysaccharide to enhance bioactivity by the anti-solvent precipitation method

BACKGROUND

Corn silk is a very important by-product of corn production with medicinal value. Corn silk polysaccharide (CSP) is the main active ingredient. In the present study, ultrasound and spheroidization by anti-solvent were applied to improve the biological activity of CSP.

RESULTS

The results showed that ultrasonic degradation improved the α-glucosidase inhibitory activity of CSP by changing its physicochemical characteristics. As the anti-solvent ratio increased, the particle size of the nanoparticles (NPs) from the spheroidization of ultrasonic-degraded corn silk polysaccharide (UCSP) gradually increased, and NP-1 exhibited the highest inhibitory effect of α-glucosidase. Isothermal titration calorimetry (ITC) results indicated that the enhanced activity might be due to more α-glucosidase binding sites with NP-1 compared with no spheroidization. Western blotting results showed that NP-1 could improve the 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) uptake in the L6 cells by regulating the phosphatidylinositol 3-kinase (PI3K)/Akt signal pathway and the translocation of glucose transporter 4 (GLUT4). NP-1 also exhibited excellent stability in different environments.

CONCLUSION

The study revealed that ultrasonic treatment and spheroidization processing showed potential applications for improving the biological activity of polysaccharides. © 2021 Society of Chemical Industry.

The effect of aerobic exercise on the expression of mir-126 and related target genes in the endothelial tissue of the cardiac muscle of diabetic rats

BACKGROUND

The aim of this study was to investigate the effect of 8 weeks of aerobic exercise on the expression of mir-126 and some angiogenesis factors in the endothelial tissue of the cardiac muscle of type 2 diabetic rats.

METHODS

Sixteen male Wistar rats were divided into two groups: diabetic control and diabetic training. Nicotinamide and streptozotocin injections were used to induce type 2 diabetes. After familiarization, the training group participated in an 8-week exercise protocol on a treadmill with an intensity of 25 m per minute, a slope of 5% and 30 min per session. RT-PCR was used to evaluate the expression of mir-126 and PI3K genes. Expression of raf1, VEGF, blood glucose and insulin was determined by ELISA and insulin resistance was assessed by HOMA-IR homeostasis model. Immunohistochemistry was used to measure the capillary density of the cardiac muscle. Data were analyzed by t-test for independent groups with a significance level of p < 0.05.

RESULTS

Diabetes reduces angiogenesis in cardiac tissue, which is associated with a significant reduction in the expression of mir-126, raf1, VEGF and PI3K; while aerobic exercise increased the expression of mir-126, raf1, PI3K, VEGF. Exercise also decreased blood glucose levels and insulin resistance.

CONCLUSION

It seems that aerobic exercise can prevent the destructive effects of diabetes by activating the angiogenic pathway of cardiac tissue. Therefore, regulatory processes through mir-126, which are influenced by aerobic exercise, can be a valuable strategy in developing new treatments for diabetes.

Seasonal expressions of ERα, ERβ, EGF, EGFR, PI3K and Akt in the scent glands of the muskrats (Ondatra zibethicus)

Epidermal growth factor (EGF) is an important autocrine and/or paracrine mediator of steroid hormones to stimulate growth and differentiation in mammals. The aim of this study is to investigate seasonal expressions of estrogen receptor α (ERα), estrogen receptor β (ERβ), EGF, epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) in the scent glands of the muskrats during the breeding and non-breeding seasons. Histologically, three types of cells including the glandular cells, interstitial cells and epithelial cells were identified in the scent glands in both seasons. Immunohistochemical results showed that ERα, ERβ, EGF, EGFR, PI3K and Akt were presented in the different types of cells of the scent glands during the breeding and non-breeding seasons. Transcriptome data of the scent glandular tissues from muskrats in the breeding and non-breeding seasons showed that differential seasonal changes might be related to the estrogen-EGFR signaling pathway. The gene expression levels of ERα, ERβ, EGF, EGFR, PI3K were increased, while the gene expression level of Akt were decreased in the breeding season than those in the non-breeding season. Besides, the concentrations of 17β-estradiol (E₂) in the serum and the scent glandular tissues were remarkably higher in the breeding season than those of the non-breeding season. Taken together, our results suggested that EGFR signaling pathway may coordinate with ERs signaling to regulate the seasonal changes of the scent glandular functions.

CYRI-A limits invasive migration through macropinosome formation and integrin uptake regulation

The Scar/WAVE complex drives actin nucleation during cell migration. Interestingly, the same complex is important in forming membrane ruffles during macropinocytosis, a process mediating nutrient uptake and membrane receptor trafficking. Mammalian CYRI-B is a recently described negative regulator of the Scar/WAVE complex by RAC1 sequestration, but its other paralogue, CYRI-A, has not been characterized. Here, we implicate CYRI-A as a key regulator of macropinosome formation and integrin internalization. We find that CYRI-A is transiently recruited to nascent macropinosomes, dependent on PI3K and RAC1 activity. CYRI-A recruitment precedes RAB5A recruitment but follows sharply after RAC1 and actin signaling, consistent with it being a local inhibitor of actin polymerization. Depletion of both CYRI-A and -B results in enhanced surface expression of the α5β1 integrin via reduced internalization. CYRI depletion enhanced migration, invasion, and anchorage-independent growth in 3D. Thus, CYRI-A is a dynamic regulator of macropinocytosis, functioning together with CYRI-B to regulate integrin trafficking.

Resistance Mutations to BTK Inhibitors Originate From the NF-κB but Not From the PI3K-RAS-MAPK Arm of the B Cell Receptor Signaling Pathway

Since the first clinical report in 2013, inhibitors of the intracellular kinase BTK (BTKi) have profoundly altered the treatment paradigm of B cell malignancies, replacing chemotherapy with targeted agents in patients with chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), and Waldenström's macroglobulinemia. There are over 20 BTKi, both irreversible and reversible, in clinical development. While loss-of-function (LoF) mutations in the BTK gene cause the immunodeficiency X-linked agammaglobulinemia, neither inherited, nor somatic BTK driver mutations are known. Instead, BTKi-sensitive malignancies are addicted to BTK. BTK is activated by upstream surface receptors, especially the B cell receptor (BCR) but also by chemokine receptors, and adhesion molecules regulating B cell homing. Consequently, BTKi therapy abrogates BCR-driven proliferation and the tissue homing capacity of the malignant cells, which are being redistributed into peripheral blood. BTKi resistance can develop over time, especially in MCL and high-risk CLL patients. Frequently, resistance mutations affect the BTKi binding-site, cysteine 481, thereby reducing drug binding. Less common are gain-of-function (GoF) mutations in downstream signaling components, including phospholipase Cγ2 (PLCγ2). In a subset of patients, mechanisms outside of the BCR pathway, related e.g. to resistance to apoptosis were described. BCR signaling depends on many proteins including SYK, BTK, PI3K; still based on the resistance pattern, BTKi therapy only selects GoF alterations in the NF-κB arm, whereas an inhibitor of the p110δ subunit of PI3K instead selects resistance mutations in the RAS-MAP kinase pathway. BTK and PLCγ2 resistance mutations highlight BTK's non-redundant role in BCR-mediated NF-κB activation. Of note, mutations affecting BTK tend to generate clone sizes larger than alterations in PLCγ2. This infers that BTK signaling may go beyond the PLCγ2-regulated NF-κB and NFAT arms. Collectively, when comparing the primary and acquired mutation spectrum in BTKi-sensitive malignancies with the phenotype of the corresponding germline alterations, we find that certain observations do not readily fit with the existing models of BCR signaling.

Multi-omics approach identifies germline regulatory variants associated with hematopoietic malignancies in retriever dog breeds

Histiocytic sarcoma is an aggressive hematopoietic malignancy of mature tissue histiocytes with a poorly understood etiology in humans. A histologically and clinically similar counterpart affects flat-coated retrievers (FCRs) at unusually high frequency, with 20% developing the lethal disease. The similar clinical presentation combined with the closed population structure of dogs, leading to high genetic homogeneity, makes dogs an excellent model for genetic studies of cancer susceptibility. To determine the genetic risk factors underlying histiocytic sarcoma in FCRs, we conducted multiple genome-wide association studies (GWASs), identifying two loci that confer significant risk on canine chromosomes (CFA) 5 (P_wald = 4.83x10^-9) and 19 (P_wald = 2.25x10^-7). We subsequently undertook a multi-omics approach that has been largely unexplored in the canine model to interrogate these regions, generating whole genome, transcriptome, and chromatin immunoprecipitation sequencing. These data highlight the PI3K pathway gene PIK3R6 on CFA5, and proximal candidate regulatory variants that are strongly associated with histiocytic sarcoma and predicted to impact transcription factor binding. The CFA5 association colocalizes with susceptibility loci for two hematopoietic malignancies, hemangiosarcoma and B-cell lymphoma, in the closely related golden retriever breed, revealing the risk contribution this single locus makes to multiple hematological cancers. By comparison, the CFA19 locus is unique to the FCR and harbors risk alleles associated with upregulation of TNFAIP6, which itself affects cell migration and metastasis. Together, these loci explain ~35% of disease risk, an exceptionally high value that demonstrates the advantages of domestic dogs for complex trait mapping and genetic studies of cancer susceptibility.

We have identified two regions of the canine genome that explain a striking 35% of risk for developing histiocytic sarcoma in FCRs. The disease is uniformly lethal, affects 20% of FCRs, and parallels a cancer of the same name in humans. Both regions harbor genes involved in cell migration and cancer-related pathways. The first includes variants in regulatory regions at the tumor suppressor PIK3R6 locus that are strongly associated with histiocytic sarcoma and likely confer risk for other hematopoietic cancers. FCRs with risk alleles at the second locus demonstrate increased expression of TNFAIP6, which correlates with poor prognosis in multiple human cancers. In identifying genomic differences between affected and unaffected dogs, we advance our understanding of both canine and human health biology and set the stage for the development of diagnostic and therapeutic strategies.

Phyllanthin prevents diethylnitrosamine (DEN) induced liver carcinogenesis in rats and induces apoptotic cell death in HepG2 cells

Liver cancer is a critical clinical condition with augmented malignancy, rapid progression, and poor prognosis. Liver cancer often initiates as fibrosis, develops as cirrhosis, and results in cancer. For centuries, medicinal plants have been incorporated in various liver-associated complications, and recently, research has recognized that many bioactive compounds from medicinal plants may interact with targets related to liver disorders. Phyllanthin from the Phyllanthus species is one such compound extensively used by folklore practitioners for various health benefits. However, most practices continue to be unrecognized scientifically. Hence, in this work, we investigated the protective role of phyllanthin on diethylnitrosamine (DEN) induced liver carcinoma in Wistar Albino rats and the anti-tumor potential on human hepatocellular carcinoma (HCC) HepG2 cells. The DEN-challenged liver cancer in experimental rats caused increased liver weight, 8-OHD, hepatic tissue injury marker, lipid peroxidation, and tumor markers levels. Remarkably, phyllanthin counteracted the DEN effect by ameliorating all the liver function enzymes, oxidative DNA damage, and tumor-specific markers by enhanced anti-oxidant capacity and induced caspase-dependent apoptosis through the mTOR/ PI3K signaling pathway. MTT assay demonstrated that phyllanthin inhibited the HepG2 cell growth in a dose-dependent manner. Fascinatingly, phyllanthin did not demonstrate any substantial effect on the normal cell line, HL7702. In addition, HepG2 cells were found in the late apoptotic stage upon treatment with phyllanthin as depicted by acridine orange/ethidium bromide staining. Overall, this work offers scientific justification that phyllanthin can be claimed to be a safe candidate with potential chemotherapeutic activity against HCC.

To study the mechanism of Cuscuta chinensis Lam. And Lycium barbarum L. in the treatment of asthenospermia based on network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Cuscuta chinensis Lam. and Lycium barbarum L. (SC-FL) is a commonly used kidney tonic Chinese medicine combination that is widely used in the clinical treatment of oligoasthenospermia.However, its specific mechanism remains unclear and requires in-depth study.

AIM OF THE STUDY

To explore the potential targets of SC-FL in the treatment of oligoasthenospermia using network pharmacology, and to verify the results with in vivo and in vitro experiments.

MATERIALS AND METHODS

A herb-compound-target-disease network and PPI network were constructed with Cytoscape software. The targets of SC-FL for the treatment of male sterility were introduced into a bioinformatics annotation database, and the GO and KEGG databases were used for pathway enrichment analysis. Subsequently, Tripterygium wilfordii Hook. f. (GTW) polyglycoside was used to induce a spermatogenic dysfunction model in GC-1 spg cells and SD male rats in in vitro and in vivo experiments, respectively. The SC-FL and PI3K pathway inhibitor LY294002 was used to intervene in the spermatogenic dysfunction model to detect the expression of proteins and mRNA related to the PI3K pathway and to detect the indicators related to proliferation and apoptosis.

RESULTS

In in vitro experiments, the percentage of spermatogenic cells and the proportion of GC-1 spg cells at G0/G1 and G2/M stages in the model group (GTW group) and the inhibitor group (LY group) were significantly decreased (P < 0.01) compared with the blank control group (NC group). The apoptosis rate of the GTW group was significantly increased (P < 0.01). The ultrastructures of GC-1 spg cells in the GTW group and LY group were obviously destroyed. Compared with the GTW group, the SC-FL group had a significantly reduced apoptosis rate of GC-1 spg cells, reduced percentage of cells in S phase, and a significantly improved mitochondrial membrane potential. SC-FL can repair the ultrastructure of GC-1 spg cells damaged by GTW. The above effects of SC-FL are closely related to up-regulation of GFRa1, RET, PI3K, p-AKT, and Bcl-2 and down-regulation of BAD and BAX proteins and mRNA expression. In vivo, compared with the GTW group, the body mass, testicular mass, and epididymal weight of the GTW + SC-FL group were significantly increased (P < 0.01). Sperm concentrations and the PR + NP of GTW + SC-FL were significantly higher than in the GTW group (P < 0.01 or P < 0.05). FSH, LH, and T levels in the GTW + SC-FL and LY + SC-FL groups were significantly higher than those in the GTW and LY group (P < 0.01 or P < 0.05). HE staining results showed that the morphology of testicular tissue in the GTW + SC-FL and LY + SC-FL groups was superior to that in the GTW and LY group. The above effects of SC-FL are closely related to the up-regulation of proteins and mRNA expression of PI3K, p-AKT, and Bcl-2.

CONCLUSION

Through the PI3K/Akt signaling pathway, SC-FL up-regulates GFRa1, RET, PI3K, p-AKT, and Bcl-2, and down-regulates the expression of BAD and BAX proteins and mRNA, thus reducing the percentage of GC-1 spg cells in S-phase, significantly increasing the mitochondrial membrane potential, significantly reducing cell apoptosis, and improving sperm counts and viability.

New Therapeutic Opportunities for the Treatment of Squamous Cell Carcinomas: A Focus on Novel Driver Kinases

Squamous cell carcinomas of the lung, head and neck, esophagus, and cervix account for more than two million cases of cancer per year worldwide with very few targetable therapies available and minimal clinical improvement in the past three decades. Although these carcinomas are differentiated anatomically, their genetic landscape shares numerous common genetic alterations. Amplification of the third chromosome's distal portion (3q) is a distinguishing genetic alteration in most of these carcinomas and leads to copy-number gain and amplification of numerous oncogenic proteins. This area of the chromosome harbors known oncogenes involved in squamous cell fate decisions and differentiation, including TP63, SOX2, ECT2, and PIK3CA. Furthermore, novel targetable oncogenic kinases within this amplicon include PRKCI, PAK2, MAP3K13, and TNIK. TCGA analysis of these genes identified amplification in more than 20% of clinical squamous cell carcinoma samples, correlating with a significant decrease in overall patient survival. Alteration of these genes frequently co-occurs and is dependent on 3q-chromosome amplification. The dependency of cancer cells on these amplified kinases provides a route toward personalized medicine in squamous cell carcinoma patients through development of small-molecules targeting these kinases.

ABT-751 Induces Multiple Anticancer Effects in Urinary Bladder Urothelial Carcinoma-Derived Cells: Highlighting the Induction of Cytostasis through the Inhibition of SKP2 at Both Transcriptional and Post-Translational Levels

The objective was to investigate the anti-cancer effects and underlying molecular mechanisms of cytostasis which were activated by an anti-microtubule drug, ABT-751, in two urinary bladder urothelial carcinoma (UBUC)-derived cell lines, BFTC905 and J82, with distinct genetic backgrounds. A series of in vitro assays demonstrated that ABT-751 induced G₂/M cell cycle arrest, decreased cell number in the S phase of the cell cycle and suppressed colony formation/independent cell growth, accompanied with alterations of the protein levels of several cell cycle regulators. In addition, ABT-751 treatment significantly hurdled cell migration and invasion along with the regulation of epithelial–mesenchymal transition-related proteins. ABT-751 triggered autophagy and apoptosis, downregulated the mechanistic target of rapamycin kinase (MTOR) and upregulated several pro-apoptotic proteins that are involved in extrinsic and intrinsic apoptotic pathways. Inhibition of autophagosome and autolysosome enhanced apoptosis was also observed. Through the inhibition of the NFκB signaling pathway, ABT-751 suppressed S-phase kinase associated protein 2 (SKP2) transcription and subsequent translation by downregulation of active/phospho-AKT serine/threonine kinase 1 (AKT1), component of inhibitor of nuclear factor kappa B kinase complex (CHUK), NFKB inhibitor alpha (NFKBIA), nuclear RELA proto-oncogene, NFκB subunit (RELA) and maintained a strong interaction between NFKBIA and RELA to prevent RELA nuclear translocation for SKP2 transcription. ABT-751 downregulated stable/phospho-SKP2 including pSKP2(S64) and pSKP2(S72), which targeted cyclin-dependent kinase inhibitors for degradation through the inactivation of AKT. Our results suggested that ABT-751 may act as an anti-cancer drug by inhibiting cell migration, invasion yet inducing cell cycle arrest, autophagy and apoptosis in distinct UBUC-derived cells. Particularly, the upstream molecular mechanism of its anticancer effects was identified as ABT-751-induced cytostasis through the inhibition of SKP2 at both transcriptional and post-translational levels to stabilize cyclin dependent kinase inhibitor 1A (CDKN1A) and CDKN1B proteins.

Mechanisms of Insulin Resistance at the Crossroad of Obesity with Associated Metabolic Abnormalities and Cognitive Dysfunction

Obesity mediates most of its direct medical sequelae through the development of insulin resistance (IR). The cellular effects of insulin occur through two main postreceptor pathways that are the phosphatidylinositol 3-kinase (PI3-K) and the mitogen-activated protein kinase (MAP-K) pathways. Obesity-related IR implicates the PI3-K pathway that confers the metabolic effects of insulin. Numerous and complex pathogenic pathways link obesity with the development of IR, including chronic inflammation, mitochondrial dysfunction (with the associated production of reactive oxygen species and endoplasmic reticulum stress), gut microbiota dysbiosis and adipose extracellular matrix remodelling. IR itself plays a key role in the development of metabolic dysfunction, including hypertension, dyslipidaemia and dysglycaemia. Furthermore, IR promotes weight gain related to secondary hyperinsulinaemia, with a resulting vicious cycle of worsening IR and its metabolic sequelae. Ultimately, IR underlies obesity-related conditions such as type 2 diabetes mellitus (T2D) and polycystic ovary syndrome (PCOS). IR also underlies many obesity-related malignancies, through the effects of compensatory hyperinsulinaemia on the relatively intact MAP-K insulin pathway, which controls cellular growth processes and mitoses. Furthermore, the emergent data over recent decades support an important role of obesity- and T2D-related central IR in the development of cognitive dysfunction, including effects on hippocampal synaptic plasticity. Importantly, IR is largely reversible through the optimisation of lifestyle factors that include regular engagement in physical activity with the avoidance of sedentariness, improved diet including increased fibre intake and sleep sufficiency. IR lies at the key crossroad between obesity and both metabolic and cognitive dysfunction. Given the importance of IR in the pathogenesis of many 21st century chronic diseases and its eminent reversibility, it is important that we all embrace and facilitate optimised lifestyles to improve the future health and wellbeing of the populace.

Postnatal overfeeding induces hepatic microRNA-221 expression and impairs the PI3K/AKT pathway in adult male rats

BACKGROUND

Increasing evidence suggests that postnatal overfeeding induces childhood obesity, which is strongly associated with metabolic syndrome. Insulin resistance is a risk factor for metabolic syndrome. MicroRNA-221 (miR-221) is involved in the development of obesity and has been reported to negatively regulate insulin sensitivity. However, the underlying mechanism remains unclear.

METHODS

Rats raised in small litters (SLs, three pups/dam, n = 10) and normal litters (NLs, 10 pups/dam, n = 10) were used to model early postnatal overfeeding and act as controls, respectively. miR-221 and proteins related to the phosphoinositide 3-kinases (PI3K)/protein kinase B (AKT) pathway were assessed in the liver.

RESULTS

Early postnatal overfeeding significantly increased body weight, visceral fat index, blood glucose, serum triglycerides, and the homeostasis model assessment of insulin resistance at 9 weeks. Real-time polymerase chain reaction (PCR) and western blot analysis revealed that postnatal overfeeding induced insulin receptor and insulin receptor substrate 2 expression, but decreased PI3K and AKT phosphorylation in the liver. Quantitative real-time PCR showed that hepatic miR-221 was significantly overexpressed in the SL group.

CONCLUSIONS

These results indicate that postnatal overfeeding induces hepatic miR-221 overexpression and impairs the PI3K/AKT signal pathway, which may cause insulin resistance.

IMPACT

We first report postnatal overfeeding induces hepatic miR-221 expression. Postnatal overfeeding impairs PI3K/AKT pathway in the liver of adult rats. Postnatal overfeeding induces obesity and high blood glucose. Avoidance of overfeeding during early postnatal life may prevent obesity and T2DM.

Growth Factor Receptor Signaling Inhibition Prevents SARS-CoV-2 Replication

SARS-CoV-2 infections are rapidly spreading around the globe. The rapid development of therapies is of major importance. However, our lack of understanding of the molecular processes and host cell signaling events underlying SARS-CoV-2 infection hinders therapy development. We use a SARS-CoV-2 infection system in permissible human cells to study signaling changes by phosphoproteomics. We identify viral protein phosphorylation and define phosphorylation-driven host cell signaling changes upon infection. Growth factor receptor (GFR) signaling and downstream pathways are activated. Drug-protein network analyses revealed GFR signaling as key pathways targetable by approved drugs. The inhibition of GFR downstream signaling by five compounds prevents SARS-CoV-2 replication in cells, assessed by cytopathic effect, viral dsRNA production, and viral RNA release into the supernatant. This study describes host cell signaling events upon SARS-CoV-2 infection and reveals GFR signaling as a central pathway essential for SARS-CoV-2 replication. It provides novel strategies for COVID-19 treatment.

Peroxisome Proliferator-Activated Receptor γ Coactivator 1α Activates Vascular Endothelial Growth Factor That Protects Against Neuronal Cell Death Following Status Epilepticus through PI3K/AKT and MEK/ERK Signaling

Status epilepticus may cause molecular and cellular events, leading to hippocampal neuronal cell death. Peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) is an important regulator of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2), also known as fetal liver kinase receptor 1 (Flk-1). Resveratrol is an activator of PGC-1α. It has been suggested to provide neuroprotective effects in epilepsy, stroke, and neurodegenerative diseases. In the present study, we used microinjection of kainic acid into the left hippocampal CA3 region in Sprague Dawley rats to induce bilateral prolonged seizure activity. Upregulating the PGC-1α pathway will increase VEGF/VEGFR2 (Flk-1) signaling and further activate some survival signaling that includes the mitogen activated protein kinase kinase (MEK)/mitogen activated protein kinase (ERK) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathways and offer neuroprotection as a consequence of apoptosis in the hippocampal neurons following status epilepticus. Otherwise, downregulation of PGC-1α by siRNA against pgc-1α will inhibit VEGF/VEGFR2 (Flk-1) signaling and suppress pro-survival PI3K/AKT and MEK/ERK pathways that are also accompanied by hippocampal CA3 neuronal cell apoptosis. These results may indicate that the PGC-1α induced VEGF/VEGFR2 pathway may trigger the neuronal survival signaling, and the PI3K/AKT and MEK/ERK signaling pathways. Thus, the axis of PGC-1α/VEGF/VEGFR2 (Flk-1) and the triggering of downstream PI3K/AKT and MEK/ERK signaling could be considered an endogenous neuroprotective effect against apoptosis in the hippocampus following status epilepticus.

Inositol Polyphosphate-Based Compounds as Inhibitors of Phosphoinositide 3-Kinase-Dependent Signaling

Signaling pathways regulated by the phosphoinositide 3-kinase (PI3K) enzymes have a well-established role in cancer development and progression. Over the past 30 years, the therapeutic potential of targeting this pathway has been well recognized, and this has led to the development of a multitude of drugs, some of which have progressed into clinical trials, with few of them currently approved for use in specific cancer settings. While many inhibitors compete with ATP, hence preventing the catalytic activity of the kinases directly, a deep understanding of the mechanisms of PI3K-dependent activation of its downstream effectors led to the development of additional strategies to prevent the initiation of this signaling pathway. This review summarizes previously published studies that led to the identification of inositol polyphosphates as promising parent molecules to design novel inhibitors of PI3K-dependent signals. We focus our attention on the inhibition of protein-membrane interactions mediated by binding of pleckstrin homology domains and phosphoinositides that we proposed 20 years ago as a novel therapeutic strategy.

Reconstitution of an RNA Virus Replicase in Artificial Giant Unilamellar Vesicles Supports Full Replication and Provides Protection for the Double-Stranded RNA Replication Intermediate

Positive-strand RNA [(+)RNA] viruses are important pathogens of humans, animals, and plants and replicate inside host cells by coopting numerous host factors and subcellular membranes. To gain insights into the assembly of viral replicase complexes (VRCs) and dissect the roles of various lipids and coopted host factors, we have reconstituted Tomato bushy stunt virus (TBSV) replicase using artificial giant unilamellar vesicles (GUVs). We demonstrate that reconstitution of VRCs on GUVs with endoplasmic reticulum (ER)-like phospholipid composition results in a complete cycle of replication and asymmetrical RNA synthesis, which is a hallmark of (+)RNA viruses. TBSV VRCs assembled on GUVs provide significant protection of the double-stranded RNA (dsRNA) replication intermediate against the dsRNA-specific RNase III. The lipid compositions of GUVs have pronounced effects on in vitro TBSV replication, including (-) and (+)RNA synthesis. The GUV-based assay has led to the discovery of the critical role of phosphatidylserine in TBSV replication and a novel role for phosphatidylethanolamine in asymmetrical (+)RNA synthesis. The GUV-based assay also showed stimulatory effects by phosphatidylinositol-3-phosphate [PI(3)P] and ergosterol on TBSV replication. We demonstrate that eEF1A and Hsp70 coopted replicase assembly factors, Vps34 phosphatidylinositol 3-kinase (PI3K) and the membrane-bending ESCRT factors, are required for reconstitution of the active TBSV VRCs in GUVs, further supporting that the novel GUV-based in vitro approach recapitulates critical steps and involves essential coopted cellular factors of the TBSV replication process. Taken together, this novel GUV assay will be highly suitable to dissect the functions of viral and cellular factors in TBSV replication.IMPORTANCE Understanding the mechanism of replication of positive-strand RNA viruses, which are major pathogens of plants, animals, and humans, can lead to new targets for antiviral interventions. These viruses subvert intracellular membranes for virus replication and coopt numerous host proteins, whose functions during virus replication are not yet completely defined. To dissect the roles of various host factors in Tomato bushy stunt virus (TBSV) replication, we have developed an artificial giant unilamellar vesicle (GUV)-based replication assay. The GUV-based in vitro approach recapitulates critical steps of the TBSV replication process. GUV-based reconstitution of the TBSV replicase revealed the need for a complex mixture of phospholipids, especially phosphatidylserine and phosphatidylethanolamine, in TBSV replication. The GUV-based approach will be useful to dissect the functions of essential coopted cellular factors.

Discovery of the PTEN Tumor Suppressor and Its Connection to the PI3K and AKT Oncogenes

PTEN (phosphatase and tensin homolog on chromosome 10) was discovered over 20 years ago in 1997 and linked to the phosphatidylinositol 3-kinase (PI3K) and AKT oncogenes the following year. The discovery of PTEN emerged from the linked concepts of oncogenes and tumor suppressor genes that cause and prevent cancer and the fields of tumor viruses and human cancer genetics from which these two concepts arose. While much has been learned since, the initial discovery and characterization, including the discovery that PTEN is a regulator of PI3K and AKT, provide the foundation on which we continue to build our knowledge. To provide the context in which these cancer genes were discovered, background information that led to their discovery will also be discussed, which will hopefully be a useful guide for readers seeking to build on the work of others.

Agriophyllum oligosaccharides ameliorate hepatic injury in type 2 diabetic db/db mice targeting INS-R/IRS-2/PI3K/AKT/PPAR-γ/Glut4 signal pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Agriophyllum squarrosum (L.) Moq. is a traditional Mongol medicine generally used to treat diabetes.

OBJECTIVE

To investigate the protective effects and potential mechanisms of Agriophyllum oligosaccharides (AOS) on liver injury in type 2 diabetic db/db mice.

MATERIALS AND METHODS

The db/db mice were divided into the model group (Model), metformin group (MET), high-dose AOS group (HAOS), and low-dose AOS group (LAOS). Nondiabetic littermate control db/m mice were used as the normal control group (Control). Mice in AOS groups were treated with AOS (380 or 750 mg/kg) daily, for 8 weeks. At 8 weeks, blood samples were collected to detect lipid and enzyme parameters concerning hepatic function, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein (TP), albumin (ALB), globulin (GLB), triglyceride (TG), total cholesterol (TC), and high-density lipoprotein cholesterol (HDL-C). Random blood glucose (RBG) test, oral glucose tolerance test (OGTT), and oral maltose tolerance test (OMTT) were also conducted. Microscopy was used to observe morphological changes in the liver of AOS-treated groups. Real-time PCR was used to detect the mRNA expression, including insulin receptor substrate 2 (IRS-2), phosphatidylinositol 3 kinase (PI3K), protein kinase B (AKT), peroxisome proliferator-activated receptor (PPAR)-γ, insulin receptor (INS-R), and Glut4. Furthermore, western blotting was performed to identify proteins, including phosphorylation of IRS-2 (p-IRS-2), PI3K, p-AKT, PPAR-γ, INS-R, and Glut4. Hepatic protein expression of p-IRS-2, PI3K, p-AKT, PPAR-γ, INS-R, and Glut4 was observed using immunohistochemical staining.

RESULTS

AOS treatment significantly decreased RBG, OGTT, and OMTT in mice, as well as serum ALT and AST activities. AOS groups demonstrated significantly higher expressions of p-IRS-2, PI3K, PPAR-γ, p-AKT, INS-R, and Glut4 protein and IRS-2, PI3K, AKT, PPAR-γ, INS-R, and Glut4 mRNA in the liver tissue of db/db mice; the degeneration and necrosis of hepatocytes and formation of collagen fibres markedly reduced, improving the structural disorder in the liver.

CONCLUSION

The results suggest that AOS could protect the liver in type 2 diabetes, in part by activating insulin in the INS-R/IRS2/PI3K/AKT/Glut4/PPAR-γ signal pathway, facilitating hepatocyte proliferation, and further reducing the blood glucose levels.

Hydrazinocurcumin and 5-fluorouracil enhance apoptosis and restrain tumorigenicity of HepG2 cells via disrupting the PTEN-mediated PI3K/Akt signaling pathway

Hydrazinocurcumin (HZC), a curcumin analogue, serves as a tumor suppressor in breast cancer and lung cancer. In this study, we investigate the role and mechanism of HZC in regulating HepG2 cell apoptosis and tumorigenicity, and its synergistic effects with 5-fluorouracil (5-Fu). HepG2 cells were treated with HZC and/or 5-Fu to analyze the possible synergistic effects on cell proliferation, apoptosis and cell cycle distribution in vitro using EdU staining, Hoechst staining and flow cytometry, respectively. For mechanistic investigation we used pic, a phosphatase and tensin homolog (PTEN) inhibitor, and in other studies assessed the expression pattern of PTEN and PI3K/Akt signaling pathway-related genes. Additionally, we tested in vivo effects of HZC and 5-Fu treatment on growth of HepG2 cell tumors in nude mice. We found that HZC or 5-Fu induced apoptosis and repressed proliferation of HepG2 cells by upregulating the expression of PTEN and disrupting the PI3K/Akt signaling pathway activation. Moreover, HZC had a higher pro-apoptotic effect than 5-Fu. HZC and 5-Fu induced HepG2 cell apoptosis and inhibited their tumorigenicity in vivo. Inhibition of PTEN expression activated the PI3K/Akt signaling pathway and reversed the protective effects of HZC or 5-Fu. Thus, HZC and 5-Fu increase PTEN, which blocks the PI3K/Akt signaling pathway, ultimately inducing HepG2 cell apoptosis. Importantly, the synergistic combination of HZC and 5-Fu may present promising strategy for the treatment of HCC.

Sodium Propionate Attenuates the Lipopolysaccharide-Induced Epithelial-Mesenchymal Transition via the PI3K/Akt/mTOR Signaling Pathway

Short-chain fatty acids (SCFAs), especially propionate, originate from the fermentation of dietary fiber in the gut and play a key role in inhibiting pulmonary inflammation. Chronic inflammation may induce an epithelial-mesenchymal transition (EMT) in alveolar epithelial cells and result in fibrotic disorders. This study was designed to investigate the beneficial effect of sodium propionate (SP) on lipopolysaccharide (LPS)-induced EMT. In cultured BEAS-2B cells, the protein expression levels of E-cadherin, α-smooth muscle actin (SMA), and vimentin were 0.66 ± 0.20, 1.44 ± 0.23, and 1.32 ± 0.21 in the LPS group vs 1.11 ± 0.36 (P < 0.05), 1.04 ± 0.30 (P < 0.05), and 0.96 ± 0.13 (P < 0.01) in the LPS + SP group (mean ± standard deviation), respectively. Meanwhile, LPS-triggered inflammatory cytokines and extracellular proteins were also reduced by SP administration in BEAS-2B cells. Moreover, SP treatment attenuated inflammation, EMT, extracellular matrix (ECM) deposition, and even fibrosis in a mouse EMT model. In terms of mechanism, LPS-treated BEAS-2B cells exhibited a higher level of phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) phosphorylation, which was interrupted by SP treatment. It is worth noting that the blockade of the PI3K/Akt/mTOR signaling cascade reduced the LPS-evoked EMT process in BEAS-2B cells. These results suggest that SP can block LPS-induced EMT via inhibition of the PI3K/Akt/mTOR signaling cascade, which provides a basis for possible clinical use of SP in airway and lung diseases.

Mutation-Associated Phenotypic Heterogeneity in Novel and Canonical PIK3CA Helical and Kinase Domain Mutants

Phosphatidylinositol 3-kinase, catalytic subunit alpha (PIK3CA) is an oncogene often mutated in colorectal cancer (CRC). The contribution of PIK3CA mutations in acquired resistance to anti-epidermal growth factor receptor (EGFR) therapy is well documented, but their prognostic and predictive value remain unclear. Domain- and exon-specific mutations are implicated in either favorable or poor prognoses, but there is paucity in the number of mutations characterized outside of the mutational hotspots. Here, two novel non-hotspot mutants-Q661K in exon 13 and C901R in exon 19-were characterized alongside the canonical exon 9 E545K and exon 20 H1047R mutants in NIH3T3 and HCT116 cells. Q661K and E545K both map to the helical domain, whereas C901R and H1047R map to the kinase domain. Results showed variable effects of Q661K and C901R on morphology, cellular proliferation, apoptosis resistance, and cytoskeletal reorganization, with both not having any effect on cellular migration. In comparison, E545K markedly promoted proliferation, survival, cytoskeletal reorganization, migration, and spheroid formation, whereas H1047R only enhanced the first three. In silico docking suggested these mutations negatively affect binding of the p85 alpha regulatory subunit to PIK3CA, thereby relieving PIK3CA inhibition. Altogether, these findings support intra-domain and mutation-specific variability in oncogenic readouts, with implications in degree of aggressiveness.

Structural and functional characterization of Solanum lycopersicum phosphatidylinositol 3-kinase C2 domain

Phosphatidylinositol 3-kinases (PI3Ks) are characterized by the presence of a C2 domain at the N-terminal end (class I, III); or at both the N-terminal and C-terminal ends (class II), sometimes including a Plextrin homology domain and/or a Ras domain. Plant PI3Ks are analogous to the class III mammalian PI3K. An N-terminal fragment (~170 aa) of the tomato PI3K regulatory domain including the C2 domain, was cloned and expressed in a bacterial system. This protein was purified to homogeneity and its physicochemical properties analyzed. The purified protein showed strong binding with monophosphorylated phosphatidylinositols, and the binding was dependent on calcium ion concentration and pH. In the overall tertiary structure of PI3K, C2 domain showed unique characteristics, having three antiparallel beta-sheets, hydrophobic regions, acidic as well as alkaline motifs, that can enable its membrane binding upon activation. To elucidate the functional significance of C2 domain, transgenic tobacco plants expressing the C2 domain of PI3K were generated. Transgenic plants showed defective pollen development and disrupted seed set. Flowers from the PI3K-C2 transgenic plants showed delayed wilting, and a decrease in ethylene production. It is likely that introduction of the PI3K-C2 segment may have interfered with the normal binding of PI3K to the membrane, delaying the onset of membrane lipid catabolism that lead to senescence.

Cracking the context-specific PI3K signaling code

Specificity in signal transduction is determined by the ability of cells to "encode" and subsequently "decode" different environmental signals. Akin to computer software, this "signaling code" governs context-dependent execution of cellular programs through modulation of signaling dynamics and can be corrupted by disease-causing mutations. Class IA phosphoinositide 3-kinase (PI3K) signaling is critical for normal growth and development and is dysregulated in human disorders such as benign overgrowth syndromes, cancer, primary immune deficiency, and metabolic syndrome. Despite decades of PI3K research, understanding of context-dependent regulation of the PI3K pathway and of the underlying signaling code remains rudimentary. Here, we review current knowledge on context-specific PI3K signaling and how technological advances now make it possible to move from a qualitative to quantitative understanding of this pathway. Insight into how cellular PI3K signaling is encoded or decoded may open new avenues for rational pharmacological targeting of PI3K-associated diseases. The principles of PI3K context-dependent signal encoding and decoding described here are likely applicable to most, if not all, major cell signaling pathways.

Molecular biology of oral cavity squamous cell carcinoma

Oral cavity squamous cell carcinoma (OCSCC) is a heterogeneous and complex disease that arises due to dysfunction of multiple molecular signaling pathways. Recent advances in high-throughput genetic sequencing technologies coupled with innovative analytical techniques have begun to characterize the molecular determinants driving OCSCC. An understanding of the key molecular signaling networks underlying the initiation and progression of is essential for informing treatment of the disease. In this chapter, we discuss recent findings of key genes altered in OCSCC and potential treatments targeting these genes.

Gymnemic Acid Ameliorates Hyperglycemia through PI3K/AKT- and AMPK-Mediated Signaling Pathways in Type 2 Diabetes Mellitus Rats

Gymnemic acid (GA) isolated from Gymnema sylvestre (Retz.) Schult. has been shown to have antihyperglycemic activity; however, the molecular mechanisms governing these effects are unclear. In this study, GA (40 and 80 mg kg^-1 day^-1) was evaluated by type 2 diabetes mellitus (T2DM) rats to explore its hypoglycemic activity and underlying mechanisms of action. The results indicated that GA decreased fasting blood glucose (FBG) concentrations by 26.7% and lowered insulin concentrations by 16.1% after oral administration of GA at a dose of 80 mg kg^-1 day^-1 for 6 weeks in T2DM rats. Our data showed that real-time polymerase chain reaction and western blot indicated that GA upregulated the level of phosphatidylinositol-3-kinase (PI3K) and glycogen synthesis (GS) and promoted the phosphorylation of protein kinase B (Akt) while downregulated the expression of glycogen synthesis kinase-3β (GSK-3β) in T2DM rats. In addition, key proteins involved in adenosine monophosphate (AMP)-activated protein kinase (AMPK)-mediated gluconeogenesis [such as phosphoenolpyruvate carboxy kinase (PEPCK) and glucose-6-phosphatase (G6Pase)] were downregulated in GA-treated T2DM rats. In summary, the hypoglycemic mechanisms of GA may be related to promoting insulin signal transduction and activating PI3K/Akt- and AMPK-mediated signaling pathways in T2DM rats.

Whole Grain Brown Rice Extrudate Ameliorates the Symptoms of Diabetes by Activating the IRS1/PI3K/AKT Insulin Pathway in db/db Mice

The therapeutic benefits of whole grains on diabetes mellitus have been continuously confirmed by in-depth research. To date, limited studies have investigated the effect of extruded products of whole grains on the insulin signaling pathway in vivo. This study investigated the effects of oral consumption of whole grain extrudate, including 97% brown rice and 3% defatted rice bran (w/w, BRD), on glucose metabolism and the hepatic insulin signaling pathway in C57BL/KsJ-db/db mice. BRD treatment induced a remarkable reduction in blood glucose. Moreover, glucose intolerance and insulin resistance were ameliorated in the BRD-treated group compared with those in the db/db control group. BRD also increased the hepatic glycogen content by reducing the expression and increasing the phosphorylation of glycogen synthase kinase 3β (GSK3β). The activities of glucose-6-phosphatase and phosphoenolpyruvate carboxylase and their respective mRNA expression levels in the liver were simultaneously decreased in the BRD-treated group. BRD also significantly upregulated the expression of phosphatidylinositol 3-kinase (PI3K) and increased the phosphorylation of insulin receptor substrate 1 (IRS1) and protein kinase B (AKT). These results indicate that BRD exhibits antidiabetic potential by activating the IRS1/PI3K/AKT signaling pathway, further regulating the expression of the FOXO1 gene and p-GSK3β protein, thus inhibiting hepatic gluconeogenesis, increasing hepatic glycogen storage, and improving insulin resistance. Therefore, BRD could be used as a functional ingredient to alleviate the symptoms of hyperglycemia.

The Hippo pathway integrates PI3K-Akt signals with mechanical and polarity cues to control tissue growth

The Hippo signalling pathway restricts cell proliferation in animal tissues by inhibiting Yes-associated protein (YAP or YAP1) and Transcriptional Activator with a PDZ domain (TAZ or WW-domain-containing transcriptional activator [WWTR1]), coactivators of the Scalloped (Sd or TEAD) DNA-binding transcription factor. Drosophila has a single YAP/TAZ homolog named Yorkie (Yki) that is regulated by Hippo pathway signalling in response to epithelial polarity and tissue mechanics during development. Here, we show that Yki translocates to the nucleus to drive Sd-mediated cell proliferation in the ovarian follicle cell epithelium in response to mechanical stretching caused by the growth of the germline. Importantly, mechanically induced Yki nuclear localisation also requires nutritionally induced insulin/insulin-like growth factor 1 (IGF-1) signalling (IIS) via phosphatidyl inositol-3-kinase (PI3K), phosphoinositide-dependent kinase 1 (PDK1 or PDPK1), and protein kinase B (Akt or PKB) in the follicular epithelium. We find similar results in the developing Drosophila wing, where Yki becomes nuclear in the mechanically stretched cells of the wing pouch during larval feeding, which induces IIS, but translocates to the cytoplasm upon cessation of feeding in the third instar stage. Inactivating Akt prevents nuclear Yki localisation in the wing disc, while ectopic activation of the insulin receptor, PI3K, or Akt/PKB is sufficient to maintain nuclear Yki in mechanically stimulated cells of the wing pouch even after feeding ceases. Finally, IIS also promotes YAP nuclear localisation in response to mechanical cues in mammalian skin epithelia. Thus, the Hippo pathway has a physiological function as an integrator of epithelial cell polarity, tissue mechanics, and nutritional cues to control cell proliferation and tissue growth in both Drosophila and mammals.

16α-Hydroxytrametenolic Acid from Poria cocos Improves Intestinal Barrier Function Through the Glucocorticoid Receptor-Mediated PI3K/Akt/NF-κB Pathway

This study evaluated the effect of triterpenoids from edible mushroom Poria cocos on intestinal epithelium integrity and revealed the transcriptional regulatory pathways that underpin restorative mechanisms in the gut. Based on computational docking studies, transcriptional activation experiments and glucocorticoid receptor (GR) protein immunofluorescence localization assays in cultured cells, 16α-hydroxytrametenolic acid (HTA) was discovered as a novel GR agonist in this study. HTA ameliorates TNF-α-induced Caco-2 monolayer intestinal epithelial barrier damage and suppressed activation of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt), which attenuated downstream IκB and nuclear factor kappa-B (NF-κB) phosphorylation through GR activation. Moreover, HTA prevented NF-κB translocation into the nucleus and binding to its cis-element and suppressed lipopolysaccharide-induced downstream NO production and pro-inflammatory cytokines at both protein and mRNA expression levels. In conclusion, HTA from P. cocos improves intestinal barrier function through a GR-mediated PI3K/Akt/NF-κB signaling pathway and may be potentially exploited as a supportive dietary therapeutic strategy for restoring gut health.

Functional differentiation of three phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) in response to Vibrio anguillarum infection in turbot (Scophthalmus maximus)

PIK3CA has been extensively investigated from its molecular mechanism perspective and association with its mutations in different types of cancers. However, little has been reported regarding the pathological significance of PIK3CA expression in teleost. Here, in our present study, three PIK3CA genes termed SmPIK3CAa, SmPIK3CAb and SmPIK3CA-like were firstly identified in the genome of turbot S. maximus. Although these three genes located in different chromosomes, all of them share the same five domains. Phylogenetic and synteny analysis indicated that SmPIK3CAa, SmPIK3CAb and SmPIK3CA-like were three paralogs that may originate from duplication of the same ancestral PIK3CA gene. Subcellular localization analysis confirmed the cytoplasm distribution of these three paralogs. All three SmPIK3CA were ubiquitously expressed in examined tissues in turbot, with the higher expression levels in immune-related tissues such as blood, spleen, kidney, gills and intestines. Upon Vibrio anguillarum challenge, SmPIK3CAa and SmPIK3CA-like transcripts were significantly induced in spleen, intestine and blood despite of differential expression levels and responsive time points. Additionally, individuals in resistant group showed significantly higher expression level of both two genes than in the susceptible group. Moreover, four SNPs (102, 2530, 3027 and 3060) and one haplotype (Hap2) located in exon region of SmPIK3CA-like were identified and confirmed to be associated with V. anguillarum resistance in turbot by association analysis in different populations. Taken together, these results suggested that functional differentiation occurred in three SmPIK3CA paralogs with Vibrio anguillarum resistance and SmPIK3CAa and SmPIK3CA-like probable play potential roles in innate immune response to pathogenic invasions in turbot.

Inhibition of Phosphatidylinositol 3-kinase (PI3K) Signaling Synergistically Potentiates Antitumor Efficacy of Paclitaxel and Overcomes Paclitaxel-Mediated Resistance in Cervical Cancer

Acquired paclitaxel (PTX) resistance limits its effectiveness and results in advanced cancer progression. This review investigated whether the inhibition of phosphatidylinositol 3-kinase (PI3K) signaling overcomes paclitaxel resistance in cervical cancer. It was established paclitaxel-resistant cell lines (PTX-R ME180/PTX-R HeLa) and determined the combination index for paclitaxel and PI3K inhibitors (BYL-719/ LY294002) by tetrazolium dye assay. Flow cytometry was used to detect the cell cycle and apoptosis. Migration and invasion were explored by wound healing and transwell assays. Genes related to multiple pathways were assessed by a western blot. It was found that the PI3K pathway was significantly activated in paclitaxel-resistant HeLa and ME180 cells compared to parental cells. PTX + PI3K inhibitor combined therapy showed a synergistic effect by strengthening paclitaxel-induced S and G2M arrest in PTX-R cell sublines by the inactivation of cyclin A1, cyclin B1, cyclin E, and Cdc2 expression. Moreover, combination therapy significantly enhanced drug sensitivity and apoptosis through the activation of Bax, and cleavage of poly-(ADP-ribose) polymerase compared with paclitaxel alone. In addition, PI3K inhibition also suppressed tumor migration and invasion by targeting β-catenin and matrix metalloproteinase-2/9. The authors suggest that the combination of a PI3K inhibitor with paclitaxel may enhance antitumor activity through a cascade of PI3K signaling events.

AIMP1 regulates TCR signaling and induces differentiation of regulatory T cells by interfering with lipid raft association

In addition to a role in translation, AIMP1 is secreted to affect various immune cells, such as macrophages, dendritic cells, B cells, and natural killer cells. However, the direct effects of AIMP1 on T cells have not yet been reported. In this study, we investigated whether AIMP1 could modulate T cell responses directly. Results revealed that AIMP1 significantly inhibited T cell receptor (TCR)-dependent activation and proliferation of CD4 T cells, as well as decreased TCR stimuli-induced Ca²⁺ influx in CD4 T cells. In addition, microscopic analysis revealed that lipid raft association in response to TCR engagement was significantly reduced in the presence of AIMP1, and the phosphorylation of PLCγ and PI3K was also down-regulated in CD4 T cells by AIMP1. Furthermore, AIMP1 specifically enhanced the differentiation of regulatory T (Treg) cells, while it had no effect on T helper type 1 (Th1), type 2 (Th2), and type 17 (Th17) cell differentiation. Collectively, these results indicate that AIMP1 affects T cells directly by down-regulating TCR signaling complex formation and inducing Treg cell differentiation in CD4 T cells.

Arginyl-fructosyl-glucose, a Major Maillard Reaction Product of Red Ginseng, Attenuates Cisplatin-Induced Acute Kidney Injury by Regulating Nuclear Factor κB and Phosphatidylinositol 3-Kinase/Protein Kinase B Signaling Pathways

Recently, although ginseng ( Panax ginseng C. A. Meyer) and its main component saponins (ginsenosides) have been reported to exert protective effects on cisplatin (CDDP)-induced acute kidney injury (AKI), the beneficial activities of non-saponin on CDDP-induced AKI is little known. This research was designed to explore the protective effect and underlying mechanism of arginyl-fructosyl-glucose (AFG), a major and representative non-saponin component generated during the process of red ginseng, on CDDP-caused AKI. AFG at doses of 40 and 80 mg/kg remarkably reversed CDDP-induced renal dysfunction, accompanied by the decreased levels of serum creatinine and blood urea nitrogen. Interestingly, all of oxidative stress indices were ameliorated after pretreatment with AFG continuously for 10 days. Importantly, AFG relieved CDDP-induced inflammation and apoptosis in part by mitigating the cascade initiation steps of nuclear factor κB signals and regulating the participation of the phosphatidylinositol 3-kinase/protein kinase B signal pathway. In conclusion, these results clearly provide strong rationale for the development of AFG to prevent CDDP-induced AKI.

pik3r3b, a novel immune-related gene in Nile tilapia (Oreochromis niloticus): Identification, expression and analysis of antibacterial activity

A full-length cDNA encoding phosphatidylinositol 3-kinase regulatory subunit gamma b gene in Nile tilapia (Oreochromis niloticus), termed as On-pik3r3b, was identified and characterized in this study. The sequence analysis demonstrated that the full-length cDNA of On-pik3r3b was 2018 bp, containing a 5' untranslated region (UTR) of 171 bp, an open reading frame (ORF) of 1422 bp and a 3' UTR of 425 bp. Its protein sequence displayed a high degree of identity with other fish. Using qPCR, the expression patterns of On-pik3r3b were investigated. In healthy Nile tilapia, the transcripts of On-pik3r3b were detected in all examined tissues, except the skin. Upon the stimulation with Streptococcus agalactiae, the On-pik3r3b expression level in liver, spleen, kidney and gill were significantly increased at 12 h after infection. The recombinant On-pik3r3b showed in vitro antibacterial activity, against S. agalactiae and E. coli. Our observation strongly indicates that On-pik3r3b is involved in the innate immune response in Nile tilapia.

Effects of BSF on Podocyte Apoptosis via Regulating the ROS-Mediated PI3K/AKT Pathway in DN

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). The ROS-mediated PI3K/AKT pathway plays a key role in podocyte apoptosis and DN progression. Our previous study demonstrated that Baoshenfang (BSF) can decrease proteinuria and attenuate podocyte injury. However, the effects of BSF on podocyte apoptosis induced by the ROS-mediated PI3K/AKT pathway remain unclear. Herein, in vivo and in vitro studies have been performed. In our in vivo study, BSF significantly decreased 24-h urinary protein, serum creatinine, and blood urea nitrogen levels in DN mice. Meanwhile, BSF significantly inhibited oxidative stress and podocyte apoptosis in our in vivo and in vitro studies. Moreover, BSF significantly decreased the inhibition of the PI3K/AKT pathway induced by HG in DN. More importantly, the effects of BSF on podocyte apoptosis were reversed by PI3K siRNA transfection. In conclusion, BSF can decrease proteinuria and podocyte apoptosis in DN, in part through regulating the ROS-mediated PI3K/AKT pathway.

RNA interference against the putative insulin receptor substrate gene chico affects metamorphosis in Leptinotarsa decemlineata

It is noted that insect insulin/insulin-like growth factor/target of rapamycin signaling is critical for the regulation of metamorphosis in holometabolous insects. However, the molecular mechanism remains undetermined. Our previous findings reveal that RNA interference (RNAi)-mediated knockdown of an insulin gene (LdILP2) in Leptinotarsa decemlineata disturbs both 20-hydroxyecdysone (20E) and juvenile hormone (JH) signaling, and impairs pupation. In the present paper, we further observed that the expression of the insulin receptor substrate gene chico (Ldchico) and the phosphoinositide-3-kinase gene pi3k (Ldpi3k92E) was repressed in LdILP2 depleted larvae. Moreover, RNAi of Ldchico or Ldpi3k92E decreased food consumption, affected absorption and metabolism of amino acids and sugars, and reduced expression of several 20E (LdEcR, LdHR3 and LdE75) and JH (LdJHAMT, LdKr-h1 and LdHairy) signaling genes. As a result, larval development was postponed and larval growth was inhibited. Intriguingly, knockdown of Ldchico, rather than Ldpi3k92E, impaired larval-pupal and pupal-adult ecdysis, and specifically repressed transcription of another 20E signaling gene LdUSP. Ingestion of 20E rescued the expression of LdEcR, LdHR3 and LdE75, whereas 20E feeding restored neither the decreased LdUSP mRNA level, nor the reduced pupation and adult emergence rates in Ldchico RNAi larvae. Therefore, Chico is critical for the regulation of larval-pupal-adult transition by a PI3K-independent pathway, perhaps through activation of USP in L. decemlineata.