Concurrent induction of apoptosis and necroptosis in apigenin‑treated malignant mesothelioma cells: Reversal of Warburg effect through Akt inhibition and p53 upregulation

A high dependence on aerobic glycolysis, known as the Warburg effect, is one of the metabolic features exhibited by tumor cells. Therefore, targeting glycolysis is becoming a very promising strategy for the development of anticancer drugs. In the present study, it was investigated whether pre‑adaptation of malignant mesothelioma (MM) cells to an acidic environment was associated with a metabolic shift to the Warburg phenotype in energy production, and whether apigenin targets acidosis‑driven metabolic reprogramming. Cell viability, glycolytic activity, Annexin V‑PE binding activity, reactive oxygen species (ROS) levels, mitochondrial membrane potential, ATP content, western blot analysis and spheroid viability were assessed in the present study. MM cells pre‑adapted to lactic acid were resistant to the anticancer drug gemcitabine, increased Akt activation, downregulated p53 expression, and upregulated rate‑limiting enzymes in glucose metabolism compared with their parental cells. Apigenin treatment increased cytotoxicity, Akt inactivation and p53 upregulation. Apigenin also reduced glucose uptake along with downregulation of key regulatory enzymes in glycolysis, increased ROS levels with loss of mitochondrial membrane potential, and downregulated the levels of complexes I, III and IV in the mitochondrial electron transport chain with intracellular ATP depletion, resulting in upregulation of molecules mediating apoptosis and necroptosis. Apigenin‑induced alterations of cellular responses were similar to those of Akt inactivation by Ly294002. Overall, the present results provide mechanistic evidence supporting the anti‑glycolytic and cytotoxic role of apigenin via inhibition of the PI3K/Akt signaling pathway and p53 upregulation.

Transcriptome profiling of cisplatin resistance in triple-negative breast cancer: New insight into the role of PI3k/Akt pathway

BACKGROUND

Aggressive nature of triple negative breast cancer (TNBC) is associated with poor prognosis compared with other breast cancer types. Current guidelines recommend the use of Cisplatin for the management of TNBC. However, the development of resistance to cisplatin is the primary cause of chemotherapy failure.

OBJECTIVE

In the present study, we aimed to develop a stable cisplatin-resistant TNBC cell line to investigate the key pathways and genes involved in cisplatin-resistant TNBC.

METHODS

The MDA-MB-231 cell was exposed to different concentrations of cisplatin. After 33 generations, cells showed a resistant phenotype. Then, RNA-sequencing analysis was performed in cisplatin-resistant and parent cell lines. The RNA-sequencing data was verified by quantitative PCR (qPCR).

RESULTS

The IC50 of the resistant cell increased to 10-fold of parental cell (p<0.001). Also, cisplatin-resistant cells show cross-resistance to other drugs, including 5-fluorouracil, paclitaxel, and doxorubicin. Resistant cells demonstrated reduced drug accumulation compared to the parental cells. Results showed there were 116 differentially expression genes (DEGs) (p<0.01). Gene ontology analysis revealed that the DEGs have several molecular functions, including binding and transporter activity. Functional annotation showed that the DEGs were enriched in the drug resistance-related pathways, especially the PI3K-Akt signaling pathway. The most important genes identified in the protein-protein interaction network were heme oxygenase 1 (HMOX1) and TIMP metallopeptidase inhibitor 3 (TIMP3).

CONCLUSION

We have identified several pathways and DEGs associated with the PI3K-Akt pathway, which provides new insights into the mechanism of cisplatin resistance, and potential drug targets in TNBC.

Are TRPA1 and TRPV1 channel-mediated signalling cascades involved in UVB radiation-induced sunburn?

Burn injuries are underappreciated injuries associated with substantial morbidity and mortality. Overexposure to ultraviolet (UV) radiation has dramatic clinical effects in humans and is a significant public health concern. Although the mechanisms underlying UVB exposure are not fully understood, many studies have made substantial progress in the pathophysiology of sunburn in terms of its molecular aspects in the last few years. It is well established that the transient receptor potential ankyrin 1 (TRPA1), and vanilloid 1 (TRPV1) channels modulate the inflammatory, oxidative, and proliferative processes underlying UVB radiation exposure. However, it is still unknown which mechanisms underlying TRPV1/A1 channel activation are elicited in sunburn induced by UVB radiation. Therefore, in this review, we give an overview of the TRPV1/A1 channel-mediated signalling cascades that may be involved in the pathophysiology of sunburn induced by UVB radiation. These data will undoubtedly help to explain the various features of sunburn and contribute to the development of novel therapeutic approaches to better treat it.

Exosomal microRNA-23b-3p from bone marrow mesenchymal stem cells maintains T helper/Treg balance by downregulating the PI3k/Akt/NF-κB signaling pathway in intracranial aneurysm

Bone marrow mesenchymal stem cells (BMSCs) are involved in cancer initiation and metastasis, and sometimes mediate cell communication by releasing exosomes and delivering microRNAs (miRNAs). The study aims to investigate the effects of exosomal hsa-miR-23b-3p derived from human BMSCs on intracranial aneurysm (IA). Firstly, human BMSCs-derived exosomes were extracted by ultra-high speed centrifugation. After clinical specimen collection, imbalance of T helper (Th) 17/Treg was found in patients with IA. Then, basilar artery aneurysm models were established and BMSCs-derived exosomes were isolated and identified. The results showed that BMSCs-derived exosomes improved pathological remodeling of IA wall, upregulated the contractile phenotype and inhibited the secretory phenotype of smooth muscle cells and reduced the number of Th17 cells to maintain the balance of Th17/Treg. In addition, human BMSCs-derived exosomes inhibited the activation of the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt)/nuclear factor-kappa B (NF-κB) signaling pathway and maintained Th17/Treg balance, which in turn interfered with aneurysm formation. Finally, the targeting relationship between hsa-miR-23b-3p and KLF5 was confirmed. We further noted that BMSCs-derived exosomal hsa-miR-23b-3p inhibited IA formation by targeting KLF5 through suppression of the PI3k/Akt/NF-κB signaling pathway. All in all, our study concluded that BMSCs-derived exosomal hsa-miR-23b-3p could maintain Th17/Treg balance by targeting KLF5 through suppression of the PI3k/Akt/NF-κB signaling pathway, thus inhibit IA formation.

Pyrazinamide enhances lipid peroxidation and antioxidant levels to induce liver injury in rat models through PI3k/Akt inhibition

Pyrazinamide (PZA) is an anti-tuberculosis drug known to causes liver injury. phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) signaling protects against liver injury by promoting cellular antioxidant defenses and reducing intracellular reactive oxygen species (ROS) and lipid peroxidation. The regulatory mechanisms and functions of PI3K/Akt signaling during the hepatotoxicity of PZA are however not fully understood. Rats were administered PZA or/and the PI3K activator (740Y-P) for 7 days. The levels of serum parameters were examined via standard enzymatic techniques and the pathological status of the liver was confirmed by H & E staining. The levels of lipid peroxidation and antioxidant production were determined using commercial kits. Liver apoptosis was assessed by TUNEL staining. The expression of apoptosis-related proteins and PI3K/Akt signaling were assessed by western blot analysis. PZA treatment significantly increased serum alanine transaminase, aspartate transaminase, gamma-glutamyl transpeptidase and tall bilirubin leading to liver damage in rats. PZA also facilitated lipid peroxidation and suppressed antioxidant defenses. PZA led to apoptotic induction in rat liver cells through the downregulation of Bcl-2 and the upregulation of Bax and caspase-3. PZA also dramatically inhibited PI3K/Akt signaling in rat liver cells. We further verified that PI3K/Akt signaling in response to 740Y-P could attenuate hepatic injury, lipid peroxidation and apoptosis in rat liver cells in response to PZA. We reveal that PZA-induced liver injury in rats occurs through PI3k/Akt signaling, the recovery of which prevents liver injury in rat models.

bFGF overexpression adipose derived mesenchymal stem cells improved the survival of pulmonary arterial endothelial cells via PI3k/Akt signaling pathway

Pulmonary arterial hypertension (PAH) is characterized as pulmonary arterial endothelial dysfunction and endothelial cells over proliferation, therefore, the repair of pulmonary arterial endothelial cells has been a common goal in treating PAH. In the present study, human adipose derived mesenchymal stem cells (ASCs) were transfected with bFGF lentiviral vector and co-cultured with monocrotaline pyrrole treated human pulmonary arterial endothelial cells (HPAECs). The results showed that bFGF-ASCs improved the proliferation, viability and decreased the apoptosis of HPAECs, besides, improved PAH was observed in PAH rat models. Western blot analysis showed that the PI3k and p-Akt protein expression level increased in HPAECs, suggesting the activation of the PI3k/Akt signaling pathway. With the administration of LY294002, the bFGF induced HPAECs survival and PI3k/Akt signaling activation were successfully blocked. The present study demonstrated that bFGF transfected ASCs improved the survival of HPAECs by activating the PI3k/Akt pathway.

Antitumor effects of duvelisib on Epstein-Barr virus-associated lymphoma cells

Epstein–Barr virus (EBV) is a ubiquitous oncogenic virus that is associated with B cell lymphomas, including Burkitt lymphoma and Hodgkin lymphoma. Previous studies have shown that the phosphatidylinositol 3‐kinase (PI3K)/Akt pathway is activated in EBV‐associated lymphomas and can be a novel therapeutic target. An oral dual inhibitor of PI3Kγ and PI3Kδ, duvelisib, is in clinical trials for the treatment of lymphoid malignancies. In this study, we evaluated how duvelisib affects the activity of the PI3K/Akt signaling pathway and if it has antitumor effects in EBV‐associated lymphoma cell lines. We found that the PI3K/Akt signaling pathway was activated in most of the B and T cell lymphoma cell lines tested. Additionally, duvelisib treatment inhibited cellular growth in the tested cell lines. Overall, B cell lines were more susceptible to duvelisib than T and NK cell lines in vitro regardless of EBV infection. However, the additional influence of duvelisib on the tumor microenvironment was not assessed. Duvelisib treatment induced both apoptosis and cell cycle arrest in EBV‐positive and ‐negative B cell lines, but not in T cell lines. Furthermore, duvelisib treatment reduced the expression of EBV lytic genes (BZLF1 and gp350/220) in EBV‐positive B cell lines, suggesting that duvelisib suppresses the lytic cycle of EBV induced by B cell receptor signaling. However, duvelisib did not induce a remarkable change in the expression of EBV latent genes. These results may indicate that there is therapeutic potential for duvelisib administration in the treatment of EBV‐associated B cell lymphomas and other B cell malignancies.

Effects of connective tissue growth factor (CTGF/CCN2) on condylar chondrocyte proliferation, migration, maturation, differentiation and signalling pathway

CCN2, also known as connective tissue growth factor (CTGF), is a 38 kDa cysteine-rich extracellular matrix protein that regulates a sequence of cellular functions and participates in multiple complex biological processes, such as chondrogenesis and osteogenesis. In the present study, we provided the first evidence describing the physiological role of CCN2 in condylar chondrocyte proliferation, migration, maturation and differentiation. CCN2 was widely expressed throughout the whole layers of condylar cartilage and predominantly distributed in the proliferative zone. Recombinant CCN2 promoted the proliferation, migration, proteoglycan synthesis and differentiation capacity of isolated condylar chondrocytes. The stimulatory effect of CCN2 on chondrocyte proliferation was associated with the activation of phosphatidylinositol 3-kinase/Akt signalling pathway. The blocking of this pathway by its inhibitor LY294002 impaired the proliferative effect of CCN2 on chondrocytes. These results suggested a novel physiological role of CCN2 in the development of condylar cartilage.

Association of rs1801157 single nucleotide polymorphism of CXCL12 gene in breast cancer in Pakistan and in-silico expression analysis of CXCL12-CXCR4 associated biological regulatory network

Background

C-X-C chemokine ligand 12 (CXCL12) has important implications in breast cancer (BC) pathogenesis. It is selectively expressed on B and T lymphocytes and is involved in hematopoiesis, thymocyte trafficking, stem cell motility, neovascularization, and tumorigenesis. The single nucleotide polymorphism (SNP) rs1801157 of CXCL12 gene has been found to be associated with higher risk of BC.

Methods

Our study focuses on the genotypic and allelic distribution of SNP (rs1801157; G/A) in Pakistani population as well as its association with the clinico-pathological features. The association between rs1801157 genotypes (G/A) and BC risks was assessed by a multivariate logistic regression (MLR) analysis. Genotyping was performed in both healthy individuals and patients of BC using PCR-restriction fragment length polymorphism (PCR-RFLP) method. Furthermore, in-silico approaches were adapted to investigate the association of CXCL12 and its receptor CXCR4 with genes/proteins involved in BC signalling.

Results

Significant differences in allelic and genotypic distribution between BC patients and healthy individuals of genotype (G/G) and (A/G) (p < 0.05) were observed. The frequency of the allele G in the BC group (77%) was significantly higher as compared to control group (61%) (p = 0.01). The association of genotype GG with clinico-pathological features including age, stages of cancer and organ (lung, liver, bones and brain) metastasis (p > 0.05) was assessed. In a MLR analysis, a number of variables including age, weight of an individual, affected lymph nodes, hormonal status (estrogen and progesterone receptor), alcohol consumption and family history associated with the GG genotype (GG:AA, odds ratio (OR) = 1.30, 95% CI [1.06–1.60]) were found to be independent risk factors for BC. Our in-vitro results suggest that genotype GG is possibly increasing the risk of BC in Pakistani cohorts. in-silico analysis finds that CXCL12–CXCR4 is associated with an increased expression of PDZK1, PI3k and Akt which lead the breast tumor towards metastasis.

Conclusion

Multiple targets such as CXCL12, CXCR4, PDZK1, PI3k and Akt can be inhibited in combined strategies to treat BC metastasis.

[Effect of platycodin D on radiosensitivity of human hepatoma cell line and related mechanisms of action]

Objective: To investigate the effect of platycodin D on the radiosensitivity of human hepatoma cell lines HepG2 and SMMC-7721 and related mechanisms of action. Methods: MTT assay was used to analyze the effect of different concentrations of platycodin D with different treatment times on cell viability. The cells were pretreated with 5 μg/ml platycodin D for 24 hours followed by X-ray irradiation at different radiation doses. Colony-forming assay was used to measure the radiosensitizing effect of platycodin D on cells. The quasi-threshold dose (Dq), mean lethal dose (Do), extrapolation number (N), sensitizer enhancement ratio (SER), and survival fraction (SF) at different radiation doses were calculated, and the multi-target single-hit model was used to fit the cell survival curve according to the formula SF = l-(l-e(-D/D0))N. Flow cytometry was used to investigate the distribution of cell cycle, and Western blotting was used to measure the changes in the protein expression of phosphorylated phosphatidylinositol 3'-kinase (pPI3K), phosphorylated protein kinase (pAkt), nuclear factor-κB (NF-κB), and phosphorylated nuclear factor inhibiting protein (pIκBα). A one-way analysis of variance, the t-test, or the least significant difference test was used for statistical analysis based on the type of data. Results: Platycodin D reduced the viability of HepG2 and SMMC-7721 cells in a dose-dependent manner; the IC50 value for HepG2 cells was 24.2 ± 0.61 μg/ml at 24 hours and 7.68 ± 0.46 μg/ml at 48 hours, and that for SMMC-7721 cells was 23.8 ± 0.57 μg/ml at 24 hours and 8.63 ± 0.86 μg/mL at 48 hours. After the combined treatment with platycodin D and irradiation, there were significant reductions in Dq (P = 0.002), Do (P = 0.002), and N value (P = 0.003), the survival curve markedly shifted to the left, and SER was 1.347 ± 0.04 in HepG2 cells and 1.418 ± 0.05 in SMMC-7721 cells. In addition, platycodin D significantly inhibited the increase in the proportion of cells in G2/M phase, the increases in the protein expression of pPI3k (P = 0.002), pAkt (P = 0.003), and NF-κB (P = 0.002), and the reduction in the protein expression of pIκBα (P = 0.003). Conclusion: Platycodin D can increase the radiosensitivity of HepG2 or SMMC-7721 cells, possibly by enhancing the growth inhibition effect of irradiation and inhibiting the activation of the PI3k/Akt and NF-κB pathways.

Interleukin-3 Prevents Cellular Death Induced by Oxidative Stress in HEK293 Cells

Interleukin-3 (IL-3) is a well-characterized growth factor in hematopoietic cells, but it is also expressed in other cell types with poorly described functions. Many studies have provided evidence that IL-3 plays an important role in cell survival. We have previously shown that IL-3 is able to increase glucose uptake in HEK293 cells, suggesting that this factor requires sustained glucose metabolism to promote cell survival. In this study, we demonstrate that IL-3 contributes to cell survival under oxidative stress, a prominent feature in the pathophysiology of cancer, diabetes, and neurodegenerative diseases, as well as in the aging process. Our results suggest a molecular mechanism that involves signaling pathways mediated by PI-3k/Akt and Erk. Altogether, these findings show an important role for IL-3 in supporting the viability of non-hematopoietic systems. J. Cell. Biochem. 118: 1330-1340, 2017. © 2016 Wiley Periodicals, Inc.

Silymarin Protects Mouse Liver and Kidney from Thioacetamide Induced Toxicity by Scavenging Reactive Oxygen Species and Activating PI3K-Akt Pathway

Silymarin (SMN) has been shown to possess a wide range of biological and pharmacological effects. Besides, SMN has antioxidant and free radical scavenging activities. Thioacetamide (TAA) is a well-documented liver toxin that requires oxidative bioactivation to elicit its hepatotoxic effect which ultimately modifies amine-lipids and proteins. Our study has been designed in a TAA exposed mouse model to investigate whether SMN could protect TAA-induced oxidative stress mediated hepatic and renal damage. Results suggest that TAA generated reactive oxygen species (ROS), caused oxidative stress and induced apoptosis in the liver and kidney cells via JNK as well as PKC and MAPKs signaling. All these detrimental effects of TAA could, however, be suppressed by SMN which not only scavenged ROS but also induced PI3K-Akt cell survival pathway in the liver and prevented apoptotic pathways in both the organs. Histological studies, collagen staining and DNA fragmentation analysis also supported our results. Combining, we say that SMN possess beneficial role against TAA mediated hepatic and renal pathophysiology.

Early single Aspirin-triggered Lipoxin blocked morphine anti-nociception tolerance through inhibiting NALP1 inflammasome: Involvement of PI3k/Akt signaling pathway

Clinical usage of opioids in pain relief is dampened by analgesic tolerance after chronic exposure, which is related to opioid-associated neuroinflammation. In the current study, which is based on a chronic morphine tolerance rat model and sustained morphine treatment on primary neuron culture, it was observed that Akt phosphorylation, cleaved-Caspase-1-dependent NALP1 inflammasome activation and IL-1β maturation in spinal cord neurons were significantly enhanced by morphine. Moreover, treatment with LY294002, a specific inhibitor of PI3k/Akt signaling, significantly reduced Caspase-1 cleavage, NALP1 inflammasome activation and attenuated morphine tolerance. Tail-flick tests demonstrated that pharmacological inhibition on Caspase-1 activation or antagonizing IL-1β dramatically blocked the development of morphine tolerance. The administration of an exogenous analogue of lipoxin, Aspirin-triggered Lipoxin (ATL), caused a decline in Caspase-1 cleavage, inflammasome activation and mature IL-1β production and thus attenuated the development of morphine tolerance by inhibiting upstream Akt phosphorylation. Additionally, treatment with DAMGO, a selective μ-opioid receptor peptide, significantly induced Akt phosphorylation, Caspase-1 cleavage and anti-nociception tolerance, all of which were attenuated by ATL treatment. Taken together, the present study revealed the involvement of spinal NALP1 inflammasome activation in the development of morphine tolerance and the role of the μ-receptor/PI3k-Akt signaling/NALP1 inflammasome cascade in this process. By inhibiting this signaling cascade, ATL blocked the development of morphine tolerance.

Neuroprotective effects of treadmill exercise on BDNF and PI3-K/Akt signaling pathway in the cortex of transgenic mice model of Alzheimer's disease

(AD). Although physical exercise and AD have received attention in the scientific literature, the mechanism through which treadmill exercise may impact the brain insulin signaling of AD has not been elucidated. This study aimed to evaluate the neuroprotective effects of treadmill exercise on apoptotic factors (Bcl-2/Bax ratio, caspase-3), HSP70, COX-2, BDNF and PI3-K/Akt signaling pathway in the cortex of NSE/hPS2m transgenic mice model of AD. Treadmill exercise ameliorated cognitive function in water maze test and significantly increased the level of Bcl-2/Bax ratio and HSP-70 in Tg-exe group compared to Tg-con group; on the other hand, it significantly decreased the expression of caspase-3 and COX-2 in Tg-exe group compared to Tg-con group. In addition, treadmill exercise significantly increased the expression of BDNF and PI3K/Akt in Tg-exe group compared to Tg-con group. Consequently, treadmill exercise improves cognitive function possibly via activating neurotrophic factor, BDNF and PI3k/Akt signaling pathway, and Aβ-induced neuronal cell death in the cortex of Tg mice was markedly suppressed following treadmill exercise. These results suggest that treadmill exercise may be beneficial in preventing or treating Alzheimer's disease.