Bax Signaling Pathways Research Articles

Novel Advances in Cell-Free Therapy for Premature Ovarian Failure (POF): A Comprehensive Review.

Premature ovarian failure (POF), is a condition characterized by the early decline of ovulation function. POF is a complex disorder that can be caused by various factors, and the idiopathic form represents a significant proportion of POF patients. Hormone replacement therapy (HRT) is currently considered the first-line treatment for POF. This review aims to provide a comprehensive overview of recent advancements in platelet-rich plasma (PRP), in vitro activation (IVA), stem cell therapy, exosome therapy, microRNAs, and mitochondrial targeting therapies as a promising cell-free therapeutic approach in reproductive medicine. PLT-Exos, a new generation of cells, has been used to treat POF for more than a decade and has been shown to attenuate oocyte morphology and promote the differentiation of theca cells through the upregulation of PI3K/Akt and Bcl2, as well as the downregulation of the Smad and Bax signaling pathways. This review summarizes the current state of the art in the field of PLT-Exos and discusses the advantages and limitations of their potential clinical applications.

Procyanidin C1 inhibits bleomycin-induced pulmonary fibrosis in mice by selective clearance of senescent myofibroblasts.

Pulmonary fibrosis is a formidable challenge in chronic and age-related lung diseases. Myofibroblasts secrete large amounts of extracellular matrix and induce pro-repair responses during normal wound healing. Successful tissue repair results in termination of myofibroblast activity via apoptosis; however, some myofibroblasts exhibit a senescent phenotype and escape apoptosis, causing over-repair that is characterized by pathological fibrotic scarring. Therefore, the removal of senescent myofibroblasts using senolytics is an important method for the treatment of pulmonary fibrosis. Procyanidin C1 (PCC1) has recently been discovered as a senolytic compound with very low toxicity and few side effects. This study aimed to determine whether PCC1 could improve lung fibrosis by promoting apoptosis in senescent myofibroblasts and to investigate the mechanisms involved. The results showed that PCC1 attenuates bleomycin (BLM)-induced pulmonary fibrosis in mice. In addition, we found that PCC1 inhibited extracellular matrix deposition and promoted the apoptosis of senescent myofibroblasts by increasing PUMA expression and activating the BAX signaling pathway. Our findings represent a new method of pulmonary fibrosis management and emphasize the potential of PCC1 as a senotherapeutic agent for the treatment of pulmonary fibrosis, providing hope for patients with pulmonary fibrosis worldwide. Our results advance our understanding of age-related diseases and highlight the importance of addressing cellular senescence in treatment.

Ursodeoxycholic acid loaded dual-modified graphene oxide nanocomposite alleviates cholestatic liver injury through inhibiting hepatocyte apoptosis

Ursodeoxycholic acid (UDCA) is the preferred treatment for various types of cholestasis, however, its effectiveness is limited because of its insolubility in water. We used polyethylene glycol (PEG) and cationic polymer polyethylenimine (PEI) to double-modify graphite oxide (PPG) as a drug delivery system. UDCA was successfully loaded onto PPG through intermolecular interactions to form UDCA-PPG nanoparticles. UDCA-PPG nanoparticles not only improve the solubility and dispersibility of UDCA, but also have good biocompatibility and stability, which significantly improve the delivery rate of UDCA. The results indicated that UDCA-PPG significantly reduced ROS levels, promoted cell proliferation, protected mitochondrial membrane potential, reduced DNA damage and reduced apoptosis in the DCA-induced cell model. In a mouse cholestasis model established by bile duct ligation (BDL), UDCA-PPG improved liver necrosis, fibrosis, and mitochondrial damage and reduced serum ALT and AST levels, which were superior to those in the UDCA-treated group. UDCA-PPG reduced the expression of the apoptosis-related proteins, Caspase-3 and Bax, increased the expression of Bcl-2, and reduced the expression of the oxidative stress-related proteins, NQO and HO-1, as well as the autophagy-related proteins LC3, p62 and p-p62. Therefore, UDCA-PPG can enhance the therapeutic effect of UDCA in cholestasis, by significantly improving drug dispersibility and stability, extending circulation time in vivo, promoting absorption, decreasing ROS levels, enhancing autophagy flow and inhibiting apoptosis via the Bcl-2/Bax signaling pathway.

PHGDH is Key to a Prognostic Multigene Signature and a Potential Therapeutic Target in Acute Myeloid Leukemia.

As a rate-limiting enzyme for the serine biosynthesis pathway (SSP) in the initial step, phosphoglycerate dehydrogenase (PHGDH) is overexpressed in many different tumors, and pharmacological or genetic inhibition of PHGDH promotes antitumor effects. In the present research, by analyzing several acute myeloid leukemia (AML) datasets in the Gene Expression Omnibus (GEO), we identified prognosis-related genes and constructed a multigene signature by univariate, multivariate Cox regression and LASSO regression. Subsequently, the multigene signature was confirmed through Cox, Kaplan-Meier, and ROC analyses in the validation cohort. Moreover, PHGDH acted as a risk factor and was correlated with inferior overall survival. We further analysed other datasets and found that PHGDH was overexpressed in AML. Importantly, the expression of PHGDH was higher in drug-resistant AML compared to drug-sensitive ones. In vitro experiments showed that inhibition of PHGDH induced apoptosis and reduced proliferation in AML cells, and these antitumor effects could be related to the Bcl-2/Bax signaling pathway by the noncanonical or nonmetabolic functions of PHGDH. In summary, we constructed a twenty-gene signature that could predicate prognosis of AML patients and found that PHGDH may be a potential target for AML treatment.

Cissus antractica-ZnO NPs Induce Apoptosis in A549 Cells through ROS-Generated p53/Bcl-2/Bax Signaling Pathways and Inhibition of Inflammatory Cytokines

Biogenic synthesis using medicinal plants has less harmful effects as compared to the chemical synthesis of nanoparticles. Here, for the first time, we successfully demonstrated the eco-friendly synthesis of zinc oxide nanoparticles (ZnO NPs) using an aqueous extract of Cissus antractica. The green synthesis method offers great potential for developing new medications that enhance drug bioavailability. The current work highlighted the cytotoxicity, cell death, and routes of apoptosis in lung cancer cells (A549) and inflammatory effects through synthesizing zinc oxide nanoparticles (ZnO NPs) from the Cissus antractica plant using an eco-friendly methodology. UV–visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS) were also used to characterize the synthesized ZnO nanoparticles. The average size of the NPs was 100 nm, and the NPs were crystalline in nature, as confirmed by FE-TEM and XRD analysis, respectively. In addition, the morphology of the nanoparticles analyzed by FE-TEM showed a spherical shape. The cell viability assay indicated that CA-ZnO NPs are non-toxic to normal cell lines at concentrations up to 20 µg/mL but showed significant toxicity in the A549 cell line. The nanoformulation also increased the ROS generation level in A549 lung cancer cells, and cellular apoptosis was confirmed via Hoechst and PI staining. The CA-ZnO NPs showed significant colony inhibition as well as cell migration ability that highlighted the CA-ZnO NPs as an anticancer agent. Additionally, this study demonstrated that NPs reduced the production of reactive oxygen species (ROS) and enhanced the expression of genes for BAX accumulation by releasing Cyto-c, but decreased Bcl-2 gene expression via the mitochondrial-mediated apoptosis pathway. In addition, the anti-inflammatory effect was also investigated; the CA-ZnO NPs showed significant NO inhibition ability with suppression of pro-inflammatory cytokines (TNF-α, iNOS, COX-2, IL-6, IL-8). In conclusion, Cissus antractica can be a source of significant Nano drugs with more advanced research in order to develop future anti-inflammatory and anticancer medications.

PDCD4 deficiency improved 4-vinylcyclohexene dioxide-induced mouse premature ovarian insufficiency

Research questionWhat role does programmed cell death 4 (PDCD4) play in premature ovarian insufficiency (POI)? DesignA PDCD4 gene knockout (PDCD4–/–) mouse model was constructed, a POI mouse model was established similar to human POI with 4-vinylcyclohexene dioxide (VCD), a PDCD4-overexpressed adenovirus was designed and the regulatory role in POI in vitro and in vivo was investigated. ResultsPDCD4 expression was significantly increased in the ovarian granulosa cells of patients with POI (P ≤ 0.002 protein and mRNA) and mice with VCD-induced POI (P < 0.001 protein expression in both mouse ovaries and granulosa cells). In POI-induced mice model, PDCD4 knockouts significantly increased anti-Müllerian hormone, oestrodiol and numbers of developing follicles, and the PI3K-AKT-Bcl2/Bax signalling pathway is involved in it. ConclusionThe expression and regulation of PDCD4 significantly affects the POI pathology in a mouse model. This effect is closely related to the regulation of Bcl2/Bax and the activation of the PI3K-AKT signalling pathway.

A Chinese Medicine, Huajie Xiaoliu Formula, Enhances the Anti-Colon Cancer Effect of Tegafur, Gimeracil, and Oteracil Potassium Capsules Through Bcl-2/Bax Signaling Pathway

Research Objective This study was aimed to determine the main ingredients of Huajie Xiaoliu Formula (HJF) and investigate the anti-colon cancer effect of its combination with Tegafur, Gimeracil, and Oteracil Potassium Capsules (S-1) in vivo as well as to preliminarily explore its possible mechanism. Materials and Methods The chemical composition of HJF was determined by ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). The murine colon carcinoma cell (CT 26.WT) subcutaneous xenograft model of colon cancer mice was established to evaluate the in vivo anti-colon cancer effect of HJF. Evaluation of pathological changes in tumor tissue was evaluated by hematoxylin–eosin staining. Enzyme-linked immunosorbent assay (ELISA) was used to measure the expressions of interleukin-1β (IL-1β), inflammatory cytokines interleukin (IL-6), and tumor necrosis factor-α (TNF-α) in mice serum. Immunohistochemistry was used to evaluate B cell lymphoma-2 (Bcl-2), Bax, and Ki67 protein expression in tumor tissue. Results Twenty chemicals in HJF were identified by UPLC-QTOF-MS. In vivo experiments showed that HJF has obvious inhibitory effects on the subcutaneous xenograft model of colon cancer mice. Results of ELISA showed HJF is able to increase mice body weight, inhibit tumor growth, and reduce the serum levels of IL-1β and IL-6 along with TNF-α. Immunohistochemistry results demonstrated that HJF can significantly inhibit the levels of Bax, Bcl-2, and Ki67 in mice with colon cancer transplant tumors. Furthermore, the combination of HJF and S-1 demonstrated a more significant antitumor effect than any other group in vivo. Conclusions Huajie Xiaoliu Formula is effective in CT 26.WT subcutaneous xenograft model of colon cancer mice by inhibiting tumorigenesis, metastasis, and angiogenesis through the Bcl-2/Bax signaling pathway, resulting in anti-colorectal tumor effects. Huajie Xiaoliu Formula provides a strong theoretical basis for its clinical use and also provides a basis for further research.

Effects of Manganese and Iron, Alone or in Combination, on Apoptosis in BV2 Cells.

The aim of study was to address the effects of manganese and iron, alone and in combination, on apoptosis of BV2 microglia cells, and to determine if combined exposure to these metals augments their individual toxicity. We used a murine microglial BV2 cell line. Cell cytotoxicity was analyzed by propidium iodide (PI) exclusion assay. Cell ROS production was analyzed by 2', 7'-dichlorofluorescin diacetate (DCFH-DA) probe staining. Pro-inflammatory cytokine production was monitored by ELISA. Cell apoptosis was analyzed by PE Annexin V/7-AAD staining. Mitochondrial membrane integrity was analyzed by flow cytometry. We used immunoblotting to analyze the effect of manganese, iron alone, or their combined exposure on the activation of caspase9, P53, Bax, and Bcl2 apoptosis signaling pathways. Caspase3 activity was determined using a Colorimetric. Manganese, iron, and their combined exposure for 24h induced the activation of BV2 microglia cells and increased ROS production and the expression of the inflammatory cytokines, IL-1β and TNF-α. And we also found that the apoptosis rate increased, mitochondrial membrane potential decreased, apoptosis-related proteins caspase9, P53, Bax, and Bcl2 expression increased, and caspase3 activity increased. Furthermore, we found that combined manganese-iron cytotoxicity was lower than that induced by manganese exposure alone. Manganese, iron alone, or their combination exposure can induce apoptosis in glial cells. Iron can reduce the toxicity of manganese, and there is an antagonistic effect between manganese and iron.

Role of apoptosis and autophagy in mediating tramadol-induced neurodegeneration in the rat hippocampus.

Tramadol (TRA) is an analgesic prescribed for treating mild to moderate pains, the abuse of which has increased in recent years. Chronic tramadol consumption produces neurotoxicity, although the mechanisms are unclear. The present study investigated the involvement of apoptosis and autophagy signaling pathways and the mitochondrial system in TRA-induced neurotoxicity. Sixty adult male Wistar rats were divided into five groups that received standard saline or TRA in doses of 25, 50, 75, 100, or 150mg/kg intraperitoneally for 21 days. On the 22nd day, the Open Field Test (OFT) was conducted. Jun N-Terminal Kinase (JNK), B-cell lymphoma-2 (Bcl-2), Beclin1, and Bcl-2-like protein 4 (Bax) proteins and tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were measured in rat hippocampal tissue. TRA at doses 75, 100, and 150mg/kg caused locomotor dysfunction in rats and increased total and phosphorylated forms of JNK and Beclin-1, Bax, and Caspase-3. TRA at the three higher doses also increased the phosphorylated (inactive) form of Bcl-2 level while decreasing the unphosphorylated (active) form of Bcl-2. Similarly, the protein levels of TNF-α and IL-1β were increased dose-dependently. The mitochondrial respiratory chain enzymes were reduced at the three higher doses of TRA. TRA activated apoptosis and autophagy via modulation of TNF-α or IL-1β/JNK/Bcl-2/Beclin1 and Bcl-2/Bax signaling pathways and dysfunction of mitochondrial respiratory chain enzymes.

Porcine cardiac blood - Salvia miltiorrhiza root alleviates cerebral ischemia reperfusion injury by inhibiting oxidative stress induced apoptosis through PI3K/AKT/Bcl-2/Bax signaling pathway

Ethnopharmacological relevanceSalvia miltiorrhiza Bge. mixed with porcine cardiac blood (PCB-DS) is mainly employed for the treatment of brain ischemia-induced mental disturbances, palpitations and phlegm confusion based on the traditional principle of Menghe medical sect. PCB is the guide to DS and enhances the effect of DS. However, the potential mechanism of PCB-DS preventing cerebral ischemia/reperfusion injury (CIRI) from the perspective of oxidative stress induced cell apoptosis remains unknown. Aim of the studyTo investigate the pharmacological activity and molecular mechanism of PCB-DS against CIRI. Materials and methodsDS samples processed with different methods were prepared and UPLC-Q-TOF-MS/MS was employed for qualitative analysis of the respective processing product. The middle cerebral artery occlusion reperfusion model was then established to investigate the pharmacological activities of PCB-DS. Pathological changes in the rat brain were observed by triphenyl tetrazolium chloride (TTC), hematoxylin-eosin, and TUNEL staining. The levels of IL-6, IL-1β, and TNF-α were detected by ELISA to evaluate the inflammatory damage. Metabolomics of cerebrospinal fluid was further used to explore the potential mechanism of PCB-DS in preventing CIRI. Based on this, the levels of oxidative stress-related lactate dehydrogenase (LDH), reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) were determined. The protein levels of PI3K, AKT, Bcl-2, Bax, cleaved-caspase-3, and cleaved-caspase-9 proteins of the cerebral infarct zone were finally measured by western blotting. ResultsForty-seven components were identified in four processing products. Compared to DS, the content of total aqueous components in PCB-DS was significantly increased including salvianolic acid B isomer, salvianolic acid D, salvianolic acid F, and salvianolic acid H/I/J. Among the DS, DS processed with wine, DS processed with pig blood, and DS processed with porcine cardiac blood, PCB-DS best alleviated the CIRI through the neurological score, brain infarct volume, brain histopathology and the levels of inflammatory factors in the brain. Twenty-five significant metabolites in the cerebrospinal fluid were screened out between the sham and I/R groups. They were mainly involved in the beta-alanine metabolism, histidine metabolism, and lysine degradation, which indicated that PCB-DS may inhibit oxidative stress-induced apoptosis to achieve treating ischemic stroke. The results of biomedical examination showed that PCB-DS could alleviate oxidative damage, significantly downregulate the expression of Bax, cleaved caspase-3 and cleaved caspase-9, and upregulate the expression of p-PI3K, p-AKT, and Bcl-2. ConclusionIn summary, this study demonstrated that PCB-DS alleviated CIRI and the molecular mechanism may be related to inhibiting the oxidative stress induced apoptosis through PI3K/AKT/Bcl-2/Bax signaling pathway.

Mechanism of the anti-liver fibrosis effect of Periplaneta americana extracts that promote apoptosis of HSC-T6 cells through the Bcl-2/Bax signaling pathway

Periplaneta americana L. (Blattidae) extract (PA-B) possesses anti-oxidant, anti-inflammatory, and hepatoprotective properties; however, its mechanism of action in liver fibrosis remains unclear. Herein, we investigated the hepatoprotective effect and mechanism of action of PA-B. HSC-T6 cells treated with PA-B were stimulated with TGF-β1, and immunofluorescence, western blotting, Hoechst 33342 staining, confocal laser scanning microscopy, and flow cytometry were performed. Furthermore, the effects of PA-B were verified in a rat model of hepatic fibrosis established using 40% carbon tetrachloride (CCl4). PA-B induced apoptosis of HSC-T6 cells by inhibiting proliferation (maximum inhibition ratio 99.08%), reducing mitochondrial membrane potential, and ameliorating apoptosis-related proteins (P < 0.01). PA-B (120 mg/kg) significantly alleviated CCl4-induced hepatic histopathological fibrosis and reduced the levels of aspartate aminotransferase (from 27.68 to 20.58 U/L) and alanine aminotransferase (from 16.88 to 5.93 U/L; P < 0.05 or P < 0.01). Immunohistochemistry and western blotting showed that α-SMA levels were reduced (from 0.49 to 0.23) and that the Bcl/Bax signaling pathway was significantly inhibited by PA-B (120 mg/kg; P < 0.05 or P < 0.01). PA-B exhibits anti-fibrotic effects by mediating the Bcl-2/Bax pathway and promoting HSC-T6 cell apoptosis, providing a basis for its development as a drug to treat liver fibrosis.

Ribosome Biogenesis Regulator 1 Homolog (RRS1) Promotes Cisplatin Resistance by Regulating AEG-1 Abundance in Breast Cancer Cells

Many ribosomal proteins are highly expressed in tumors and are closely related to their diagnosis, prognosis and pathological characteristics. However, few studies are available on the correlation between ribosomal proteins and chemoresistance. RRS1 (human regulator of ribosome synthesis 1), a critical nuclear protein involved in ribosome biogenesis, also plays a key role in the genesis and development of breast cancer by protecting cancer cells from apoptosis. Given that apoptosis resistance is one of the causes of the cisplatin resistance of tumor cells, our aim was to determine the relationship between RRS1 and cisplatin resistance in breast cancer cells. Here, we report that RRS1 is associated with cisplatin resistance in breast cancer cells. RRS1 silencing increased the sensitivity of MCF-7/DDP cells to cisplatin and inhibited cancer cell proliferation by blocking cell cycle distribution and enhancing apoptosis. AEG-1 (astrocyte elevated gene-1) promotes drug resistance by interfering with the ubiquitination and proteasomal degradation of MDR1 (multidrug resistance gene 1), thereby enhancing drug efflux. We found that RRS1 binds to and stabilizes AEG-1 by inhibiting ubiquitination and subsequent proteasomal degradation, which then promotes drug efflux by upregulating MDR1. Furthermore, RRS1 also induces apoptosis resistance in breast cancer cells through the ERK/Bcl-2/BAX signaling pathway. Our study is the first to show that RRS1 sensitizes breast cancer cells to cisplatin by binding to AEG-1, and it provides a theoretical basis to improve the efficacy of cisplatin-based chemotherapy.

Withania somnifera Alter BCL2/Bax signaling and trigger apoptosis of MCF-7 and MDA-MB231 breast cancer cells exposed to γ-radiation.

Treatment strategies encompass synchronization of more than one therapy with specific dependence on zeroing side effects of natural products that might represent a niche in the continuous struggle against cancer. Thus, this study aimed at assessing the role of Withania somnifera; WS (Ashwagandha) in forcing MCF7 or MDA-MB 231 irradiated breast cancer cells to outweigh the route of programmed cell death. We check to what extent SIRT1-BCL2/Bax signaling pathway was interrelated to form apoptotic cancer cells. MDA or MCF7 cells are categorized into four groups: gp1, Control (C): MDA-MB-231 or MCF7 cells not treated with WS or exposed to γ-rays, gp2 (WS): cells challenged with WS for MDA-MB-231 or MCF7 cells respectively, gp3: irradiated (R) MDA-MB-231 or MCF7 cells exposed to γ-rays (4Gy; one shot) and gp4 WS and irradiated (WS + R): cells challenged with WS as in gp2 and exposed to gamma rays as in gp3. The results revealed that, WS established IC50 equivalent to 4897.8μg/ml in MDA-MB-231 cells or equivalent to 3801.9μg/ml in MCF7 cells. The flowcytometric analysis (Annexin V and cell cycle) showed that WS induces apoptosis at pre-G phase and induces cell arrest at G2/M and preG1 phases for MDA-MB-231 and at the preG1 for MCF7 cells. Furthermore, the WS + R group of cells (MDA-MB-231 and MCF7) showed significant increases in the expression of SIRT1, and BCL2 and a decrease in BAX compared with WS or R group. It could be concluded that WS has an anti-proliferative action on MDA-MB-231 and MCF7 cells because of its capability to enhance apoptosis.

Royal jelly protects brain tissue against fluoride-induced damage by activating Bcl-2/NF-κB/caspase-3/caspase-6/Bax and Erk signaling pathways in rats.

This study is aimed at determining whether royal jelly (RJ) which has a powerful antioxidant property prevents fluoride-induced brain tissue damage and exploring whether Bcl-2/NF-κB/ and caspase-3/caspase-6/Bax/Erk pathways play a critical role in the neuroprotective effect of RJ. Wistar albino rats were chosen for the study, and they were randomly distributed into six groups: (i) control; (ii) royal jelly; (iii) fluoride-50; (iv) fluoride-100; (v) fluoride-50 + royal jelly; (vi) fluoride-100 + royal jelly. We established fluoride-induced brain tissue damage with 8-week-old male Wistar albino rats by administration of fluoride exposure (either 50mg/kg or 100mg/kg bw) through drinking water for 8weeks. Then, the study duration is for 56days where the rats were treated with or without RJ (100mg/kg bw) through oral gavage. The effects of RJ on glutathione (GSH), catalaseactivity (CAT), and malondialdehyde (MDA) levels were determined via spectrophotometer. Western blot analysis was performed to investigate the effectsof royal jelly on the protein expression levels of Bax, caspase-3, caspase-6, Bcl-2, NF-κB, COX-2, and Erk. It was also studied the effects of RJ on histopathological alterations in fluoride-induced damage to the rat brain. As a result,the Bcl-2, NF-κB, and COX-2 protein expression levels were increased in the fluoride-treated (50 and 100mg/kg) groups but theywere decreased significantly by RJ treatment in the brain tissue. Additionally, the protein expression of caspase-3, caspase-6, Bax, and Erk were decreased in fluoride-treated groups and theywere significantly increased by RJ treatment compared to theun-treated rats. Our results suggested that RJ prevented fluoride-induced brain tissue damage through anti-antioxidant activities.

Hesperidin Induced HePG-2 Cell Apoptosis through ROS-Mediated p53/Bcl-2/Bax and p-mTOR Signaling Pathways

Recently, research showed that one of the most common kinds of liver cancer is hepatocellular carcinoma (HCC), which is also the fourth main cause of cancer deaths. In studies regarding chemicals to better treat the disease, hesperidin shows a novel potential in performing anticancer activities, particularly in liver cancer. However, the specific mechanism of hesperidin that causes such activities remains a mystery. Thus, the purpose of this study is to investigate hesperidin’s effect on cell proliferation and activation of ROS-mediated signaling pathways in HePG-2 cells. Hesperidin shows a significant impact on inhibiting HePG-2 cells’ proliferation through induction of cell apoptosis by Bcl-2, Bax, and p53 pathways. Treating cells with hesperidin in a dose-dependent manner shows a significant increase in the apoptotic cell population (sub-G1). Moreover, Hesperidin’s induction of apoptotic activities shows dependence on ROS (reactive oxygen species) overproduction, further affecting the p-mTOR pathways and leading to DNA damage. Hence, the overall data demonstrate that ROS-mediated signaling pathways exhibit mechanisms that may lead to useful information for interpreting hesperidin-induced hepatocarcinoma cell apoptosis.

Quercetin induced HepG2 cells apoptosis through ATM/JNK/STAT3 signaling pathways

Liver cancer is the seventh most common malignant tumor in the world and is the second highest cause of death due to cancer. Quercetin, a flavonoid with low toxicity, widely exists in various fruits and vegetables. It has the potential to be a therapeutic agent against various cancers. This study aimed to demonstrate the anti-tumor effect of quercetin on HepG2 cells. Quercetin suppressed the HepG2 cell proliferation in a dose-dependent manner in cell viability assay. Induction of cell apoptosis was confirmed by apoptotic cells population (sub-G1 peak) detected by flow cytometer. A decrease in mitochondrial membrane potential and caspase-3 activation were also demonstrated in this study. Furthermore, quercetin induced HepG2 cell apoptosis through ROS-mediated phosphorylated ataxia-telangiectasia mutated, c-Jun Nterminal kinases, signal transducer, and activator of transcription 3 (STAT-3), and Bax signaling pathways. These results suggest that quercetin has the potential to become an effective drug against the tumor.

Protective Effect of Flavonoids against Methylglyoxal-Induced Oxidative Stress in PC-12 Neuroblastoma Cells and Its Structure-Activity Relationships.

Methylglyoxal-induced oxidative stress and cytotoxicity are the main factors causing neuronal death-related, diabetically induced memory impairment. Antioxidant and anti-apoptotic therapy are potential intervention strategies. In this study, 25 flavonoids with different substructures were assayed for protecting PC-12 cells from methylglyoxal-induced damage. A structure-activity relationship (SAR) analysis indicated that the absence of the double bond at C-2 and C-3, substitutions of the gallate group at the 3 position, the pyrogallol group at the B-ring, and the R configuration of the 3 position enhanced the protection of flavan-3-ols, and a hydroxyl substitution at the 4' and meta-positions were important for the protection of flavonol. These SARs were further confirmed by molecular docking using the active site of the Keap1-Nrf2 complex as the receptor. The mechanistic study demonstrated that EGCG with the lowest EC50 protected the PC-12 cells from methylglyoxal-induced damage by reducing oxidative stress via the Nrf2/Keap1/HO-1 and Bcl-2/Bax signaling pathways. These results suggested that flavan-3-ols might be a potential dietary supplement for protection against diabetic encephalopathy.

Nicotinamide Mononucleotide Adenylyl Transferase 2 Inhibition Aggravates Neurological Damage after Traumatic Brain Injury in a Rat Model.

Nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2) is a crucial factor for the survival of neuron. The role of NMNAT2 in damage following traumatic brain injury (TBI) remains unknown. This study was designed to investigate the role of NMNAT2 in TBI-induced neuronal degeneration and neurological deficits in rats. The TBI model was established in Sprague-Dawley rats by a weight-dropping method. Real-time polymerase chain reaction, western blot, immunofluorescence, Fluoro-Jade C staining, and neurological score analyses were carried out. NMNAT2 mRNA and protein levels were increased in the injured-side cortex at 6 hours and peaked 12 hours after TBI. Knocking down NMNAT2 with an injection of small interfering RNA in lateral ventricle significantly exacerbated neuronal degeneration and neurological deficits after TBI, which were accompanied by increased expression of BCL-2-associated X protein (Bax). NMNAT2 expression is increased and NMNAT2 exhibits neuroprotective activity in the early stages after TBI, and Bax signaling pathway may be involved in the process. Thus, NMNAT2 is likely to be an important target to prevent secondary damage following TBI.

Amygdalin attenuates PM2.5-induced human umbilical vein endothelial cell injury via the TLR4/NF-κB and Bcl-2/Bax signaling pathways.

Mounting evidence supports that long-term exposure to fine particle pollutants (PM2.5) is closely implicated in cardiovascular diseases, especially atherosclerosis. Amygdalin is reported to attenuate external stimuli-induced cardiovascular diseases. However, the underlying mechanisms are still not understood. In this study, we aim to explore the protective effects of amygdalin on PM2.5-induced human umbilical vein endothelial cell (HUVEC) injury and unravel the specific mechanisms by MTT, DCFH-DA, biochemical, immunofluorescence, ELISA, RT-qPCR, flow cytometry, TUNEL and western blot analysis. The results reveal that amygdalin reverses PM2.5-induced cytotoxicity and attenuates intracellular ROS production. Moreover, amygdalin increases the levels of SOD and GSH and alleviates the MDA content. Additionally, amygdalin causes a decline of IL-6, IL-1β, TNF-α and COX-2 levels. Moreover, amygdalin inhibits NF-κB p50 and TLR4 protein expressions and NF-κB p65 nuclear translocation. Concomitantly, a decline of phospho-NF-κB p65/NF-κB p65 and phospho-IκB-α/IκB-α is detected. Meanwhile, amygdalin pretreatment reduces HUVEC apoptosis. In addition, amygdalin triggers an upregulation of Bcl-2 and a downregulation of Bax after stimulation with PM2.5. Collectively, these results suggest that amygdalin suppresses PM2.5-induced HUVEC injury by regulating the TLR4/NF-κB and Bcl-2/Bax signaling pathways, indicating that amygdalin may be a novel target for atherosclerosis treatments.

Immunosuppression and apoptosis activation mediated by p53-Bcl2/Bax signaling pathway -The potential mechanism of goldfish (Carassius auratus Linnaeus) gill disease caused by Myxobolus ampullicapsulatus.

Myxobolus, a major harmful type of myxospora, is one of the main parasitic pathogens of freshwater fish. Once myxoboliosis occurs, treatment can be extremely difficult. Therefore, clear understandings of the etiology of myxoboliosis and its pathological mechanism are keys for prevention and control. Here, histology, transmission electron microscopy, transcriptome study, tunel assay, and immunohistochemistry were carried out, revealing the morphology, pathological effects as well as host response mechanism of goldfish gill to Myxobolus ampullicapsulatus. Histological studies showed that the mature spores of Myxobolus ampullicapsulatus were composed of three parts, the spore shell, sporoplasm and bottle shaped polar capsule containing double S-shaped polar filaments. Transcriptome analysis revealed that Myxobolus ampullicapsulatus -infected (Myx) goldfish gills were characterized by apoptosis activation mediated by “p53 signaling pathway” with significantly up-regulated apoptosis-related differential genes dominated by p53-Bcl2/Bax signaling pathway. In addition, tunel assay revealed severe gill apoptosis in the Myx group. Transcriptome analysis also revealed that Myx group showed changes in immune response and significantly down-regulated immune-related differential genes. Beyond that, immunohistochemistry showed that there was no significant increase in the number of gill lymphocyte after parasite infection. These results suggest that the pathological mechanism of Myxobolus ampullicapsulatus infection on gills of goldfish may be related to apoptosis and immunosuppression. Subsequent qRT-PCR showed that apoptosis-related genes (Caspase3,Bad, Bax) and anti-inflammatory gene IL-10 were significantly increased, while immune-related pro-inflammatory genes (IL-1β, IL-8) were markedly down-regulated, further verifying the transcriptome results. Based on the above results, we concluded that p53-Bcl2/Bax related networks that dominant the expression of apoptosis genes were activated while immunity was suppressed in the gills of Myxobolus ampullicapsulatus infected goldfish. Our study is not only of benefit to enrich the taxonomy of Myxobolus but also clarifies its pathogenic mechanism, thus providing targets for prevention and control of myxoboliosis.