Apoptosis: why and how does it occur in biology?

Hijacking the autophagy-apoptosis crosstalk: African swine fever virus orchestrates immune evasion via host remodeling for viral pathogenesis

African swine fever (ASF) is an acute, highly fatal hemorrhagic disease of domestic and wild pigs caused by African swine fever virus (ASFV). ASFV, a large double-stranded DNA virus of the Asfarviridae family, is highly infectious and pathogenic. Through modulation of host apoptosis and autophagy pathways, the virus subverts innate immune surveillance to promote its replication and dissemination. Following ASFV infection, domestic pigs may exhibit 100 % morbidity and mortality rates with highly virulent strains, constituting a major threat to the global pork industry. Nowadays, ASF is listed as a notifiable terrestrial animal disease by the World Organisation for Animal Health (WOAH). Therefore, elucidating ASFV's pathogenic mechanisms, particularly its molecular regulation of apoptosis and autophagy, is crucial for developing effective ASF control and prevention strategies. This review comprehensively summarizes the pathogenic mechanisms of ASFV, with particular focus on the autophagy-apoptosis crosstalk and viral manipulation of these cellular processes. These insights not only improve our understanding of ASFV-mediated immune evasion mechanisms but also provide valuable references for developing ASF control strategies targeting apoptosis and autophagy pathways.

Structural characterization and functional analysis of human αB-crystallin with the p.R11G mutation: Insights into cataractogenesis and cardiomyopathy

αB-crystallin, a member of the small heat-shock protein family, functions as a molecular chaperone and plays a critical role in maintaining cellular homeostasis by preventing the aggregation of misfolded proteins in various tissues. This research investigates the structural and functional consequences of the p.R11G mutation in human αB-crystallin, which is associated with serious health issues, including cataracts, myofibrillar myopathy, and dilated cardiomyopathy. Following the introduction of this mutation through site-directed mutagenesis, the mutant protein was expressed in a prokaryotic host system and purified using ion-exchange chromatography. The structure and stability of the mutant protein were assessed using various spectroscopic techniques. Moreover, the oligomeric structure of the mutant protein was examined using dynamic light scattering and atomic force microscopy. To evaluate the chaperone activity and cytoprotective effects of the protein, UV-Vis spectroscopy and the 2,5-diphenyl-2H-tetrazolium bromide (MTT) assay were utilized. The results demonstrated that the p.R11G mutation significantly alters the protein's structure, leading to enhanced thermal and chemical stability, and formation of the larger oligomers compared to the wild-type protein. Additionally, the mutation was found to increase the protein's chaperone activity and its capacity to inhibit cancer cell death under oxidative stress conditions. Based on the results of our study, the significant changes observed in the structure and activity of human αB-crystallin due to this mutation elucidate the potential role of the mutated chaperone in cataract formation and myopathy. Further research is necessary to fully elucidate the underlying mechanisms and translate these findings into effective therapeutic interventions.

Therapeutic Potential of Clove Oil in Mitigating Cadmium-Induced Hepatorenal Toxicity Through Antioxidant, Anti-Inflammatory, and Antiapoptotic Mechanisms

Hazardous heavy metals, particularly cadmium (Cd), are widely distributed in the environment and cause oxidative stress in various animal and human organs. Clove oil (CLO), a common aromatic spice, has been used as a traditional medication as it has potent anti-inflammatory, antioxidant, and hepatoprotective properties.

BACKGROUND/OBJECTIVES

This study aimed to investigate the antioxidant, antiapoptotic, and anti-inflammatory effects of clove oil (CLO) against hepatorenal toxicity induced by cadmium (Cd).

METHODS

Twenty rats were equally divided into four groups: a control group, a Cd group treated with 15 mg/kg b.wt CdCl2, a CLO group administered 200 mg/kg b.wt CLO, and a Cd+CLO group. All groups were orally treated for 4 weeks.

RESULTS

Cadmium (Cd) exposure caused anemia and hepatorenal damage, as evidenced by increased serum levels of urea, creatinine, uric acid, total bilirubin (including its direct and indirect fractions), and elevated activities of liver enzymes such as alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP). However, total protein and albumin levels decreased. Furthermore, there was a decrease in the levels of glutathione, glutathione transferase, and catalase in the liver antioxidant profiles. Meanwhile, malondialdehyde levels increased. Cadmium toxicity caused elevated expression of liver apoptosis markers, such as tumor necrosis factor-alpha (TNF-α) and caspase-3, and inflammation. CLO ameliorated the oxidative effects of Cd through decreasing urea (27.4%), creatinine (41.6%), liver enzymes, and hepatic apoptotic markers while increasing levels of total protein, albumin, and hepatic values of SOD (60.37%), CAT (64.49%), GSH (50.41%), and GST (9.16%).

CONCLUSIONS

Hematological and biochemical parameters, as well as the antioxidant system, improved following clove oil treatment, leading to a reduction in hepatorenal damage. Therefore, it is possible to conclude that CLO protects rats from inflammation, apoptosis, and hepatorenal oxidative damage caused by Cd poisoning. Comprehensive translational research is required to validate CLO's efficacy and safety of use in humans. Future studies should focus on elucidating the precise molecular mechanisms, optimal dosing strategies, and potential synergistic effects of CLO with other therapeutic agents.

Bifidobacterium longum JBLC-141 alleviates hypobaric hypoxia-induced intestinal barrier damage by attenuating inflammatory responses and oxidative stress

Hypobaric hypoxia exposure occurs at high altitudes, including plateaus, and affects normal intestinal function and microbiota composition. Exposure induces an intestinal inflammatory response and oxidative stress injury, ultimately disrupting intestinal homeostasis and causing barrier damage. Thus, due to its anti-inflammatory, antioxidative, and intestinal microbiota-regulating properties, Bifidobacterium longum is a potentially effective probiotic intervention to protect the intestinal barrier during low-pressure hypoxia on plateaus. However, its mechanism of action is not fully defined. In this study, we investigate the mechanism by which B. longum intervenes in intestinal barrier damage caused by plateau low-pressure hypoxia. To this end, an in vivo model is established by exposing rats to a simulated low-pressure hypoxic plateau environment. The experimental rats were subsequently supplemented with a B. longum strain (JBLC-141) extracted from the feces of healthy adults in Bama, Guangxi. B. longum JBLC-141 mitigates the effects of plateau low-pressure hypoxia on the rat intestinal barrier. This is achieved by activating the intestinal Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2-related factor 2 (NRF2) pathway, alleviating plateau hypoxia-induced intestinal oxidative stress injury. B. longum JBLC-141 also attenuates the inflammatory response and upregulates the expression of the tight junction proteins claudin-1, occludin, and zonula occludens-1. Furthermore, it reduces intestinal permeability, effectively ameliorating and repairing the barrier histological damage induced by the plateau low-pressure hypoxic environment. In addition, B. longum JBLC-141 positively regulates the intestinal microbiota, increasing the relative abundance of beneficial bacteria while reducing that of pathogenic bacteria and maintaining intestinal flora homeostasis in rats.

mTOR potentiates senescent phenotypes and primary cilia formation after cisplatin-induced G2 arrest in retinal pigment epithelial cells

Cisplatin, a platinum-based anticancer drug, is used to treat several types of cancer. Despite its effectiveness, cisplatin-induced side effects have often been reported. Although cisplatin-induced toxicities, such as apoptosis and/or necrosis, have been well studied, the fate of cells after exposure to sublethal doses of cisplatin needs further elucidation. Treatment with a sublethal dose of cisplatin induced cell cycle arrest at the G2 phase in retinal pigment epithelial cells. Following cisplatin withdrawal, the cells irreversibly exited the cell cycle and became senescent. Notably, the progression from the G2 to the G1 phase occurred without mitotic entry, a phenomenon referred to as mitotic bypass, resulting in the accumulation of cells containing 4N DNA content. Cisplatin-exposed cells exhibited morphological changes associated with senescence, including an enlarged size of cell and nucleus and increased granularity. In addition, the senescent cells possessed primary cilia and persistent DNA lesions. Senescence induced by transient exposure to cisplatin involves mTOR activation. Although transient co-exposure with an mTORC1 inhibitor rapamycin did not prevent mitotic bypass and entry into senescence, it delayed the progression of senescence and attenuated senescent phenotypes, resulting in shorter primary cilia formation. Conclusively, cisplatin induces senescence in retinal pigment epithelial cells by promoting mTOR activation.

Design and Synthesis of New Dihydropyrimidine Derivatives with a Cytotoxic Effect as Dual EGFR/VEGFR-2 Inhibitors

We developed and synthesized tetrahydropyrimidine derivatives as possible cytotoxic agents to inhibit EGFR and VEGFR-2 in the present study. Our study completely assesses the cytotoxic efficiency of pyrimidine-based derivatives 4-15 against various cancer cell lines, revealing derivatives 12 and 15 for their remarkable activity with GI50 values of 37 and 35 nM, respectively, when compared to the reference erlotinib (33 nM). In vitro enzyme assays showed that target compounds, particularly 12, 14, and 15, effectively inhibited EGFR and VEGFR-2. In vitro enzyme testing revealed that compound 15 was the most promising, with IC50 values of 84 and 3.50 nM for EGFR and VEGFR-2, respectively. Additionally, an in vitro assessment of the novel targets' apoptotic potential revealed that both pro-apoptotic and antiapoptotic behaviors were promising, indicating that the apoptotic induction pathway is a strongly proposed action method for the newly developed targets. Finally, molecular docking experiments are elaborately discussed to corroborate the exact binding interactions of the most active hybrids 12 and 15 with the EGFR and VEGFR-2 active sites.

pH-responsive size-adjustable liposomes induce apoptosis of fibroblasts and macrophages for rheumatoid arthritis treatment

In rheumatoid arthritis (RA), macrophages infiltrate joints, while fibroblast-like synovial cells proliferate abnormally, forming a barrier against drug delivery, which hinders effective drug delivery to joint focus. Here we firstly designed a pH-responsive size-adjustable nanoparticle, composed by methotrexate (MTX)-human serum albumin (HSA) complex coating with pH-responsive liposome (Lipo/MTX-HSA) for delivering drugs specifically to inflamed joints in acidic environments. We showed in vitro that the nanoparticles can induce mitochondrial dysfunction, promote apoptosis of fibroblast-like synoviocytes and macrophages, further reduce the secretion of inflammatory factors (TNF-α, IL-1β, MMP-9), and regulate the inflammatory microenvironment. We also demonstrated similar effects in a rat model of arthritis, in which Lipo/MTX-HSA accumulated in arthritic joints, and at low pH, liposome phospholipid bilayer cleavage released small-sized MTX-HSA, which effectively reduced the number of fibroblast-synoviocytes and macrophages in joints, alleviated joint inflammation, and repaired bone erosion. These findings suggest that microenvironment-responsive size-adjustable nanoparticles show promise as a treatment against rheumatoid arthritis. STATEMENT OF SIGNIFICANCE: Abnormal proliferation of fibroblast synoviocytes poses a physical barrier to effective nanoparticle delivery. We designed size-adjustable nano-delivery systems by preparing liposomes with cholesterol hemisuccinate (CHEM), which were subsequently loaded with small-sized albumin nanoparticles encapsulating the cytotoxic drug MTX (MTX-HSA), termed Lipo/MTX-HSA. Upon tail vein injection, Lipo/MTX-HSA could be aggregated at the site of inflammation via the ELVIS effect in the inflamed joint microenvironment. Specifically, intracellular acidic pH-triggered dissociation of liposomes promoted the release of MTX-HSA, which was further targeted to fibroblasts or across fibroblasts to macrophages to exert anti-inflammatory effects. The results showed that liposomes with adjustable particle size achieved efficient drug delivery, penetration and retention in joint sites; the strategy exerted significant anti-inflammatory effects in the treatment of rheumatoid arthritis by inducing mitochondrial dysfunction to promote apoptosis in fibrosynoviocytes and macrophages.

The mechanisms behind the dual role of long non-coding RNA (lncRNA) metastasis suppressor-1 in human tumors: Shedding light on the molecular mechanisms

When the expression levels of metastasis suppressor-1 (MTSS1) were discovered to be downregulated in a metastatic cancer cell line in 2002, it was proposed that MTSS1 functioned as a suppressor of metastasis. The 755 amino acid long protein MTSS1 connects to actin and organizes the cytoskeleton. Its gene is located on human chromosome 8q24. The suppressor of metastasis in metastatic cancer was first found to be MTSS1. Subsequent reports revealed that MTSS1 is linked to the prevention of metastasis in a variety of cancer types, including hematopoietic cancers like diffuse large B cell lymphoma and esophageal, pancreatic, and stomach cancers. Remarkably, conflicting results have also been documented. For instance, it has been reported that MTSS1 expression levels are elevated in a subset of melanomas, hepatocellular carcinoma associated with hepatitis B, head and neck squamous cell carcinoma, and lung squamous cell carcinoma. This article provides an overview of the pathological effects of lncRNA MTSS1 dysregulation in cancer. In order to facilitate the development of MTSS1-based therapeutic targeting, we also shed light on the current understanding of MTS1.

Design and synthesis of novel chloropyridazine hybrids as promising anticancer agents acting by apoptosis induction and PARP-1 inhibition through a molecular hybridization strategy

Guided by the molecular hybridization principle, a novel series of 4-chloropyridazinoxyphenyl conjugates (3a-h, 4a-e, and 5) was designed and synthesized as proposed apoptotic inducers and PARP-1 inhibitors. The growth inhibition % of the designed hybrids was investigated in eleven cancer cell lines, where the anticancer activities were found to be in the following order: 4-chloropyridazinoxyphenyl-aromatic ketones hybrids (3a-h) > 4-chloropyridazinoxyphenyl-benzyloxyphenylethan-1-one hybrids (4a-e) > 4-chloropyridazinoxyphenyl-thiazolidine-2,4-dione hybrid (5). Further, the most sensitive three cancer cell lines (HNO97, FaDu, and MDA-MB-468) were selected to measure the IC50 values of the new hybrids. Moreover, the frontier three members (3c, 3e, and 4b) were selected for the measurements of apoptotic protein markers (p53, BAX, caspase 3, caspase 6, BCL-2, and CK 18). Besides, the impact of compounds 3a-e and 4b on the activity of PARP-1 was investigated, where 3c, 3d, and 3e demonstrated comparable efficiencies to olaparib. Furthermore, γ-H2Ax, a well-established marker for double-strand DNA breaks, was examined and the occurrence of DNA damage was observed. In addition, a significant inhibition of cell proliferation and a remarkable 15 to 50-fold reduction in the number of colonies compared to the control group were recorded. Finally, the PARP-1 inhibitory potential of the novel hybrids was compared to the co-crystal of the target receptor (PDB ID: 6NTU) using molecular docking.

Mechanism of the adverse outcome of Chlorella vulgaris exposure to diethyl phthalate: Water environmental health reflected by primary producer toxicity

As a ubiquitous contaminant in aquatic environments, diethyl phthalate (DEP) is a major threat to ecosystems because of its increasing utilization. However, the ecological responses to and toxicity mechanisms of DEP in aquatic organisms remain poorly understood. To address this environmental concern, we selected Chlorella vulgaris (C. vulgaris) as a model organism and investigated the toxicological effects of environmentally relevant DEP concentrations at the individual, physiological, biochemical, and molecular levels. Results showed that the incorporation of DEP significantly inhibited the growth of C. vulgaris, with inhibition rates ranging from 10.3 % to 83.47 %, and disrupted intracellular chloroplast structure at the individual level, while the decrease in photosynthetic pigments, with inhibition rates ranging from 8.95 % to 73.27 %, and the imbalance of redox homeostasis implied an adverse effect of DEP at the physio-biochemical level. Furthermore, DEP significantly reduced the metabolic activity of algal cells and negatively altered the cell membrane integrity and mitochondrial membrane potential. In addition, the apoptosis rate of algal cells presented a significant dose-effect relationship, which was mainly attributed to the fact that DEP pollutants regulated Ca2+ homeostasis and further increased the expression of Caspase-8, Caspase-9, and Caspase-3, which are associated with internal and external pathways. The gene transcriptional expression profile further revealed that DEP-mediated toxicity in C. vulgaris was mainly related to the destruction of the photosynthetic system, terpenoid backbone biosynthesis, and DNA replication. Overall, this study offers constructive understandings for a comprehensive assessment of the toxicity risks posed by DEP to C. vulgaris.

Epigenetic mechanisms of particulate matter exposure: air pollution and hazards on human health

Environmental pollution nowadays has not only a direct correlation with human health changes but a direct social impact. Epidemiological studies have evidenced the increased damage to human health on a daily basis because of damage to the ecological niche. Rapid urban growth and industrialized societies importantly compromise air quality, which can be assessed by a notable accumulation of air pollutants in both the gas and the particle phases. Of them, particulate matter (PM) represents a highly complex mixture of organic and inorganic compounds of the most variable size, composition, and origin. PM being one of the most complex environmental pollutants, its accumulation also varies in a temporal and spatial manner, which challenges current analytical techniques used to investigate PM interactions. Nevertheless, the characterization of the chemical composition of PM is a reliable indicator of the composition of the atmosphere, the quality of breathed air in urbanized societies, industrial zones and consequently gives support for pertinent measures to avoid serious health damage. Epigenomic damage is one of the most promising biological mechanisms of air pollution-derived carcinogenesis. Therefore, this review aims to highlight the implication of PM exposure in diverse molecular mechanisms driving human diseases by altered epigenetic regulation. The presented findings in the context of pan-organic cancer, fibrosis, neurodegeneration and metabolic diseases may provide valuable insights into the toxicity effects of PM components at the epigenomic level and may serve as biomarkers of early detection for novel targeted therapies.

Rational design and eco-friendly one-pot multicomponent synthesis of novel ethylidenehydrazineylthiazol-4(5H)-ones as potential apoptotic inducers targeting wild and mutant EGFR-TK in triple negative breast cancer

A novel series of ethylidenehydrazineylthiazol-4(5H)-ones were synthesized using various eco-friendly one-pot multicomponent synthetic techniques. The anticancer activity of compounds (4a-m) was tested against 11 cancer cell lines. While the IC50 of all compounds was evaluated against the most sensitive cell lines (MDA-MB-468 and FaDu). Our SAR study pinpointed that compound 4a, having a phenyl substituent, exhibited a significant growth inhibition % against all cancer cell lines. The frontier anticancer candidates against the MDA-MB-468 were also examined against the wild EGFR (EGFR-WT) and mutant EGFR (EGFR-T790M) receptors. Most of the synthesized compounds exhibited a higher inhibitory potential against EGFR-T790M than the wild type of EGFR. Remarkably, compound 4k exhibited the highest inhibitory activity against both EGFR-WT and EGFR-T790M with IC50 values (0.051 and 0.021 µM), respectively. The pro-apoptotic protein markers (p53, BAX, caspase 3, caspase 6, caspase 8, and caspase 9) and the anti-apoptotic key marker (BCL-2) were also measured to propose a mechanism of action for the compound 4k as an apoptotic inducer for MDA-MB-468. Investigation of the cell cycle arrest potential of compound 4k was also conducted on MDA-MB-468 cancer cells. We also evaluated the inhibitory activities of compounds (4a-m) against both EGFR-WT and EGFR-T790M using two different molecular docking processes.

Apoptosis-inducing, anti-angiogenic and anti-migratory effects of a dinuclear Pd(II) complex on breast cancer: A promising novel compound

Because of the high mortality and morbidity rate of breast cancer, successful management of the disease requires synthesis of novel compounds. To this end, ongoing attempts to create new candidates include synthesis of multinuclear metal complexes. The high DNA binding affinity and cytotoxic activity of these complexes makes them promising as breast cancer treatments. This study investigated anti-growth/cytotoxic effect of the dinuclear Pd(II) complex on breast cancer cell lines (MCF-7, MDA-MB-231) using various methods of staining, flow cytometry, and immunoblotting. The study conducted colony formation, invasion, and migration assays were to assess the effect of the complex on metastasis. Increased caspase-3/7 levels and positive annexin V staining were observed in both cell lines, proving apoptosis. Altered TNFR1 and TRADD expression with caspase-8 cleavage followed by BCL-2 inactivation with loss of mitochondrial membrane potential confirmed the presence of apoptosis in MCF-7 and MDA-MB-231, regardless of p53 expression status. The results implied anti-migration properties. Finally, the study used the CAM assay to assess antiangiogenic properties and showed that the complex inhibited angiogenesis. The study concluded the dinuclear Pd(II) complex warrants further in vivo experiments to show its potential in the treatment of breast cancer.

Mesoporous tantalum oxide nanomaterials induced cardiovascular endothelial cell apoptosis via mitochondrial-endoplasmic reticulum stress apoptotic pathway

Along with its wide range of potential applications, human exposure to mesoporous tantalum oxide nanomaterials (PEG@mTa₂O₅) has substantially risen. Accumulative toxic investigations have shown the PEG@mTa₂O₅ intake and cardiovascular diseases (CVD). Endothelial cell death is crucial in the onset and development of atherosclerosis. Still, the molecular mechanism connecting PEG@mTa₂O₅ and endothelium apoptosis remains unclear. Herein, we studied the absorption and toxic action of mesoporous tantalum oxide (mTa₂O₅) nanomaterials with polyethylene glycol (PEG) utilizing human cardio microvascular endothelial cells (HCMECs). We also showed that PEG@mTa₂O₅ promoted apoptosis in endothelial cells using flow cytometry and AO-EB staining. In conjunction with the ultrastructure modifications, PEG@mTa₂O₅ prompted mitochondrial ROS production, cytosolic Ca²⁺ overload, ΔΨm collapse, and ER stress verified by elevated ER-Tracker staining, upregulated XBP1 and GRP78/BiP splicing. Remarkably, the systemic toxicity and blood compatibility profile of PEG@mTa₂O₅ can greatly improve successive therapeutic outcomes of NMs while reducing their adverse side effects. Overall, our findings suggested that PEG@mTa₂O₅-induced endothelium apoptosis was partially mediated by the activation of the endoplasmic reticulum stress-mitochondrial cascade.

Mechanisms of UV-induced human lymphocyte apoptosis

The article reviews the results of the studies of marker parameters (indicators) of various pathways and mechanisms of apoptosis of lymphocytes in donor peripheral blood induced by UV light (240-390 nm) in doses of 151, 1510, and 3020 J/m2. The article analyses the processes of DNA fragmentation, distortion of the structural asymmetry of the cell membranes, changes in the degree of DNA damage (single-strand breaks), transcriptional factor р53, cytochrome с, Fas receptors (CD95), caspase-3, caspase-8, and caspase-9, reactive oxygen species, and calcium ions in UV modified cells. The study determined that programmed cell death of lymphocytes after UV irradiation with 1510 J/m2 involves the р53-dependent pathway of the nuclear mechanism, as well as receptor-mediated caspase mechanism, mitochondrial mechanism, and the mechanism associated with the defects in calcium homeostasis. Cell death is mediated by reactive oxygen and calcium ions. The article suggests a scheme of possible intracellular events resulting in the apoptotic death of lymphocytes after UV irradiation.

Series of Organotin(IV) Compounds with Different Dithiocarbamate Ligands Induced Cytotoxicity, Apoptosis and Cell Cycle Arrest on Jurkat E6.1, T Acute Lymphoblastic Leukemia Cells

The discovery of cisplatin has influenced scientists to study the anticancer properties of other metal complexes. Organotin(IV) dithiocarbamate compounds are gaining attention as anticancer agents due to their potent cytotoxic properties on cancer cells. In this study, a series of organotin compounds were assessed for their toxic effects on the Jurkat E6.1 cell line. WST-1 assay was used to determine the cytotoxic effect of the compounds and showed that six out of seven organotin(IV) dithiocarbamate compounds exhibited potent cytotoxic effects toward T-lymphoblastic leukemia cells, Jurkat E6.1 with the concentration of IC₅₀ ranging from 0.67-0.94 µM. The apoptosis assay by Annexin V-FITC/PI staining showed that all tested compounds induced cell death mainly via apoptosis. Cell cycle analysis assessed using RNase/PI staining showed that organotin(IV) dithiocarbamate compounds induced cell cycle arrest at different phases. In conclusion, the tested organotin(IV) dithiocarbamate compounds demonstrated potent cytotoxicity against Jurkat E6.1 cells via apoptosis and cell cycle arrest at low IC₅₀ value. However, further studies on the mechanisms of action are required to probe the possible potential of these compounds on leukemia cells before they can be developed into anti-leukemic agents.

Microcystin-LR-induced autophagy regulates oxidative stress, inflammation, and apoptosis in grass carp ovary cells in vitro

MC-LR is one of the cyanotoxins produced by fresh water cyanobacteria. Previous studies showed that autophagy played an important role in MC-LR-induced reproduction toxicity. However, information on the toxicological mechanism is limited. In this study, MC-LR could induce autophagy and apoptosis in GCO cells in vitro. In GCO cells that had been exposed to MC-LR, the inhibitor of 3-MA effectively decreased cell viability and damaged cell ultrastructure. Oxidative stress was significantly increased in the 3-MA + MC-LR group, accompanied by significantly increased MDA content and decreased CAT activity and GST, SOD1, GPx, and GR expression levels (P < 0.05). Inflammation was more serious in the 3-MA + MC-LR group than that of MC-LR group, which was evidenced by increasing expression levels of TNFα, IL11, MyD88, TNFR1, TRAF2, JNK, CCL4, and CCL20 (P < 0.05). Interestingly, the significant decrease of Caspase-9, Caspase-7, and Bax expression and significant increase of Bcl-2 and Bcl-2/Bax ratio in 3-MA + MC-LR group compared to MC-LR group, suggesting that extent of apoptosis were reduced. Taken together, these results indicated that MC-LR induced autophagy and apoptosis in GCO cells, however, the inhibition of autophagy decreased the extent of apoptosis, induced more serious oxidative stress and inflammation, which eventually induced cell death. Our findings provided some information for exploring the toxicity of MC-LR, however, the role of autophagy require further study in vivo.

Conjugated Linoleic Acid strengthens the apoptotic effect of low-dose cisplatin in A549 cells by inducing Bcl-2 downregulation

One of the chemotherapeutic agents widely used in the treatment of non-small cell lung cancer (NSCLC) is cisplatin. However, the resistance of cancer cells to cisplatin and additionally serious side effects from cisplatin limit its use. Conjugated linoleic acid (CLA) has been shown to suppress the development of carcinogenesis in vitro and in vivo studies and has antitumoral activity in many cancers. The study aimed to investigate the potential effect of using cisplatin, the first-line treatment for NSCLC, in combination with CLA to increase its efficacy in low-dose use. MTT cytotoxicity assay was performed to determine the effects of CLA in combination with cisplatin on cell viability of NSCLC cell lines. The apoptotic effect of this combination on NSCLC cell lines and cell cycle distribution was determined by flow cytometry. At the same time, apoptosis and cell cycle-related gene expression levels were determined by Real-Time PCR. Combination treatment of low-dose cisplatin with CLA resulted in a significant decrease in cell viability compared to cisplatin alone, and an increase in the rate of apoptotic cells was observed. While cisplatin caused G1 phase arrest in cancer cells, there was an increase in cell percentages in S and G2 phases after combined application with CLA. In high-dose cisplatin administration, it was observed that the efficiency of the decrease in anti-apoptotic BCL2 expression related to resistance to chemotherapeutic agents was less than that of low-dose cisplatin administration. Combined administration of high-dose cisplatin with CLA significantly recovered BCL2 downregulation.

Fruit Extract of Sechium chinantlense (Lira & F. Chiang) Induces Apoptosis in the Human Cervical Cancer HeLa Cell Line

Sechium edule (Cucurbitaceae) is a commercial species of chayote and is just one of several species in the genus Sechium, whose extracts inhibit proliferation in tumor cell lines. The capacity of the wild species Sechium chinantlense (SCH) as an antitumor agent is unknown, as is the mechanism of action. In the present study, HeLa cervical cancer and HaCaT normal cell lines were treated with SCH and cell proliferation was inhibited in both cell lines in a dose-dependent manner similar to the effect of the antineoplastic agent cisplatin (Cis). Additionally, SCH arrested cell cycle progression but only in HeLa cells and induced apoptosis, as shown by phosphatidylserine translocation and caspase-3 activation, while Cis did so in both cell lines. Exploration of the mechanism of action of SCH in HeLa cells suggests that apoptosis was mediated by the intrinsic signaling pathway since there was no activation of caspase-8, but there was a release of cytochrome-c. These findings suggest that the SCH extract has the potential to selectively kill tumor cells by promoting apoptosis, without harming nontumor cells.

The Determination of Cisplatin and Luteolin Synergistic Effect on Colorectal Cancer Cell Apoptosis and Mitochondrial Dysfunction by Fluorescence Labelling

Despite the initial success of chemotherapy in the treatment of colorectal carcinoma (CRC), the recurrence of the disease shows that the tumor response is limited by the formation of drug resistance and cannot be kept under control. These drawbacks are associated with the cytostatic chemotherapeutic agent cisplatin (Cis). Combination treatment with different anticancer drugs could increase the therapeutic efficacy of combined therapies by allowing the use of lower, less toxic doses to achieve more efficient destruction of cancer cells. Luteolin (LU) has been studied with other anticancer drugs due to its anticancer cell inhibitory properties and has been shown to sensitize the cytotoxicity induced by various anticancer drugs in several cancer cells. Therefore, in this work, the CompuSyn system was used to investigate different Cis + LU combinations in HCT116 colorectal cancer cells. Immunofluorescence was used to measure mitochondrial membrane potential (MMP) and cell death. As a result, a synergistic effect was observed in 5 of the 7 doses tested. Apoptosis/necrosis resulting from chemotherapy resistance was confirmed by Hoechst/ PI -double staining and mitochondrial dysfunction were determined by Rodamine123 (Rho123). Luteolin could thus be used in medicine to provide more effective cancer therapy in appropriate doses, which promises a promising future in clinical application.

The potential mechanism of histamine-inducing cardiopulmonary inflammation and apoptosis in a novel oral model of rat intoxication

Histamine (HIS) is a potent vasodilator that contributes to anaphylactic reactions. Our investigation aims to study the possible toxic impact of repeated oral administration of histamine on the target organs of HIS poisoning (lung & heart) in rats as a model of scombroid poisoning. We used 15 rats that were separated into three groups with 5 rats in each. All rats received the treatments orally for 14 days as follows; (1): distilled water, (2) HIS at a dosage level of 250 mg/kg BWT daily and (3) HIS at a dosage level of 1750 mg/kg BWT weekly. Our results revealed that the consumption of HIS either daily or weekly could cause marked cardiopulmonary toxicity in rats. HIS can trigger inflammatory reactions in the cardiopulmonary tissues and induce oxidative stress damage along with apoptosis of such organs. HIS was markedly increase the MDA levels and decrease the CAT and GSH activity in both lung and heart tissues. The main pathological lesion observed is inflammation which was confirmed by immunohistochemistry and demonstrated strong iNOS and TNF-α protein expressions. Cardiac muscles showed extensive degeneration and necrosis and displayed strong casp-3 protein expression. Additionally, all HIS receiving groups noticed marked elevation of the pulmonary transcription levels of Cox2, TNF-α, and IL1β along with substantial elevation of casp-3 and bax genes and downregulation of Bcl2 gene in the cardiac tissue. We concluded that the oral administration of HIS either daily or weekly can induce cardiopulmonary toxicity via the upregulation of proinflammatory cytokines resulting in ROS overgeneration and inducing both oxidative stress and apoptosis.

The pathophysiological and molecular mechanisms of atmospheric PM2.5 affecting cardiovascular health: A review

BACKGROUND

Exposure to ambient fine particulate matter (PM2.5, with aerodynamic diameter less than 2.5 µm) is a leading environmental risk factor for global cardiovascular health concern.

OBJECTIVE

To provide a roadmap for those new to this field, we reviewed the new insights into the pathophysiological and cellular/molecular mechanisms of PM2.5 responsible for cardiovascular health.

MAIN FINDINGS

PM2.5 is able to disrupt multiple physiological barriers integrity and translocate into the systemic circulation and get access to a range of secondary target organs. An ever-growing body of epidemiological and controlled exposure studies has evidenced a causal relationship between PM2.5 exposure and cardiovascular morbidity and mortality. A variety of cellular and molecular biology mechanisms responsible for the detrimental cardiovascular outcomes attributable to PM2.5 exposure have been described, including metabolic activation, oxidative stress, genotoxicity, inflammation, dysregulation of Ca2+ signaling, disturbance of autophagy, and induction of apoptosis, by which PM2.5 exposure impacts the functions and fates of multiple target cells in cardiovascular system or related organs and further alters a series of pathophysiological processes, such as cardiac autonomic nervous system imbalance, increasing blood pressure, metabolic disorder, accelerated atherosclerosis and plaque vulnerability, platelet aggregation and thrombosis, and disruption in cardiac structure and function, ultimately leading to cardiovascular events and death. Therein, oxidative stress and inflammation were suggested to play pivotal roles in those pathophysiological processes.

CONCLUSION

Those biology mechanisms have deepen insights into the etiology, course, prevention and treatment of this public health concern, although the underlying mechanisms have not yet been entirely clarified.

FYCO1 regulates migration, invasion, and invadopodia formation in HeLa cells through CDC42/N-WASP/Arp2/3 signaling pathway

FYCO1, an autophagy adaptor, plays an essential role in the trafficking toward the plus-end of microtubules and the fusion of autophagosomes. Autophagic dysfunction is involved in numerous disease states, including cancers. Previous studies have implicated FYCO1 as one of the critical genes involved in the adenoma to carcinoma transition, but the biological function and mechanism of FYCO1 in carcinogenesis remain unclear. This study aims to elucidate the role and mechanism of up- and downregulation of FYCO1 in mediating tumor effects in HeLa cells. Functionally, FYCO1 promotes cellular migration, invasion, epithelial-mesenchymal transition, invadopodia formation, and matrix degradation, which are detected through wound healing, transwell, immunofluorescence, and Western blot approaches. Interestingly, the data show that although FYCO1 does not affect HeLa cell proliferation, cell cycle distribution, nor vessels' formation, FYCO1 can block the apoptotic function. FYCO1 inhibits cleavage of PARP, caspase3, and caspase9 and increases Bcl-2/Bax ratio. Then, we used CK666, an Arp2/3 specific inhibitor, to confirm that FYCO1 may promote the migration and invasion of HeLa cells through the CDC42/N-WASP/Arp2/3 signaling pathway. Taken together, these results provide a new insight that FYCO1, an autophagy adaptor, may also be a new regulator of tumor metastasis.

Cytotoxicity of BP-3 and BP-4: Blockage of extrusion pumps, oxidative damage and programmed cell death on Chlamydomonas reinhardtii

The health concern associated with the dangers related to exposure to UV radiation has led to an increase in the use of sunscreens containing UV-filters that can reach aquatic environments and possibly affect ecosystems. Benzophenone-3 (BP-3) and benzophenone-4 (BP-4) are two of the most used UV-filters. In the present work, the microalga Chlamydomonas reinhardtii was exposed to several concentrations of both chemicals. To evaluate their potential cytotoxicity on microalgal cells, different parameters were analysed including fast response biomarkers (increase in intracellular free Ca²⁺) as well as biomarkers related with the presence of oxidative stress (lipid peroxidation), energy metabolism (photosynthetic yield and cytoplasmic lipid accumulations), cell division (proliferation and F-actin content), programmed cell death (PCD) (caspase activation and DNA fragmentation) and possible mechanisms of resistance to xenobiotics (operation of extrusion pumps and presence of autophagic vacuoles). Results showed an increment of the percentage of cells with cytosolic free Ca²⁺ that could act as a secondary messenger in response to the stress. A decrease in photosynthetic yield and an increase in cytoplasmic lipid accumulations and lipid peroxidation levels were also detected. In addition, a decrease in cell proliferation was observed, linked to a decrease in the percentage of cells with F-actin. The increase observed in the microalgal population with caspase activity, together with the DNA fragmentation and the alterations in the cytoskeleton, suggested the induction of processes linked to PCD. Moreover, a blockage of extrusion pumps, which could be related to the toxicity mechanism of these compounds, and an increase in autophagic vacuoles, as an attempt to repair the damage caused by benzophenones, were detected. Overall, these biomarkers indicate that both UV-filters can be a serious threat to non-target photosynthetic microorganisms in aquatic environments, although BP-3 affected C. reinhardtii more markedly.

Adverse effects of SYP-3343 on zebrafish development via ROS-mediated mitochondrial dysfunction

As a newly-invented and highly-efficiency strobilurin fungicide, pyraoxystrobin (SYP-3343) has been recognized as a highly poisonous toxin for a variety of aquatic organisms. Nevertheless, the developmental toxicity and potential mechanism of SYP-3343 have not been well-documented. The results showed that SYP-3343 was relatively stable and maintained within the range of 20 % in 24 h, and the LC₅₀ value to embryos at 72 hpf was 17.13 μg/L. The zebrafish embryotoxicity induced by 1, 2, 4, and 8 μg/L SYP-3343 is demonstrated by repressive embryo incubation, enhancive mortality rate, abnormal heart rate, malformed morphological characteristic, and impaired spontaneous coiling, indicating SYP-3343 mostly exerted its toxicity in a dose- and time-dependent manner. Besides SYP-3343 was critically involved in regulating cell cycle, mitochondrial membrane potential, and reactive oxygen species production as well as zebrafish primary cells apoptosis, which can be mitigated using antioxidant N-acetyl-L-cysteine. A significant change occurred in total protein content, the biochemical indices, and antioxidant capacities owing to SYP-3343 exposure. Additionally, SYP-3343 altered the mRNA levels of heart development-, mitochondrial function-, and apoptosis-related genes in zebrafish embryos. These results indicated that SYP-3343 induced apoptosis accompanying reactive oxygen species-initiated mitochondrial dysfunction in zebrafish embryos.

Transcriptome analysis of developing zebrafish (Danio rerio) embryo following exposure to Gaudichaudione H reveals teratogenicity and cardiovascular defects caused by abnormal iron metabolism

Gaudichaudione H (GH), a caged polyprenylated xanthone from Garcinia plants, showed anti-cancer and anti-inflammatory effects in vitro. However, the in vivo toxicity of this compound has never been reported. The present study was aimed to address the toxic effects of Gaudichaudione H using zebrafish embryos and larvae as an in vivo test model. The zebrafish embryos were treated with GH having different concentrations (0, 0.28, 0.38 and 0.57 μg/mL). The results revealed that GH induces significant embryonic mortality, decreased heartbeat, cardiotoxicity, cardiovascular defects, increased apoptosis and decreased hemoglobinization in zebrafish embryos and larvae. According to transcriptome analysis, 1841 genes were significantly differentially expressed (1185 down-regulated and 656 up-regulated) after GH treatment. The main functions of these genes were related to iron metabolism pathways. The toxicity of GH on zebrafish embryonic development and cardiovascular may due to large amounts of downregulated genes involved in metabolic pathways and DEGs related to 'Iron ion binding' and 'Heme binding' functions.

Mechanisms of cardiovascular toxicity induced by PM2.5: a review

An increasing number of studies have shown that exposure to particulate matter with a diameter ≤ 2.5 μm (PM_2.5) could affect the onset and development of cardiovascular diseases. To explore the underlying mechanisms, the studies conducted in vitro investigations using different cell lines. In this review, we examined recently published reports cited by PubMed or Web of Science on the topic of cardiovascular toxicity induced by PM_2.5 that carried the term in vitro. Here, we summarized the suggested mechanisms of PM_2.5 leading to adverse effects and cardiovascular toxicity including oxidative stress; the increase of vascular endothelial permeability; the injury of vasomotor function and vascular reparative capacity in vascular endothelial cell lines; macrophage polarization and apoptosis in macrophage cell lines; and hypermethylation and apoptosis in the AC16 cell line and the related signaling pathways, which provided a new research direction of cardiovascular toxicity of PM_2.5.

Cyanobacteria derived compounds: Emerging drugs for cancer management

The wide diversity of cyanobacterial species and their role in a variety of biological activities have been reported in the previous few years. Cyanobacteria, especially from marine sources, constitutes a major source of biologically active metabolites that have gained great attention especially due to their anticancer potential. Numerous chemically diverse metabolites from various cyanobacterial species have been recognized to inhibit the growth and progression of tumor cells through the induction of apoptosis in many different types of cancers. These metabolites activate the apoptosis in the cancer cells by different molecular mechanisms, however, the dysregulation of the mitochondrial pathway, death receptors signaling pathways, and the activation of several caspases are the crucial mechanisms that got considerable interest. The array of metabolites and the range of mechanisms involved may also help to overcome the resistance acquired by the different tumor types against the ongoing therapeutic agents. Therefore, the primary or secondary metabolites from the cyanobacteria as well as their synthetic derivates could be used to develop novel anticancer drugs alone or in combination with other chemotherapeutic agents. In this study, we have discussed the role of cyanobacterial metabolites in the induction of cytotoxicity and the potential to inhibit the growth of cancer cells through the induction of apoptosis, cell signaling alteration, oxidative damage, and mitochondrial dysfunctions. Moreover, the various metabolites produced by cyanobacteria have been summarized with their anticancer mechanisms. Furthermore, the ongoing trials and future developments for the therapeutic implications of these compounds in cancer therapy have been discussed.

Microcystin-Induced Immunotoxicity in Fishes: A Scoping Review

Cyanobacteria (blue-green algae) have been present on Earth for over 2 billion years, and can produce a variety of bioactive molecules, such as cyanotoxins. Microcystins (MCs), the most frequently detected cyanotoxins, pose a threat to the aquatic environment and to human health. The classic toxic mechanism of MCs is the inhibition of the protein phosphatases 1 and 2A (PP1 and PP2A). Immunity is known as one of the most important physiological functions in the neuroendocrine-immune network to prevent infections and maintain internal homoeostasis in fish. The present review aimed to summarize existing papers, elaborate on the MC-induced immunotoxicity in fish, and put forward some suggestions for future research. The immunomodulatory effects of MCs in fish depend on the exposure concentrations, doses, time, and routes of exposure. Previous field and laboratory studies provided strong evidence of the associations between MC-induced immunotoxicity and fish death. In our review, we summarized that the immunotoxicity of MCs is primarily characterized by the inhibition of PP1 and PP2A, oxidative stress, immune cell damage, and inflammation, as well as apoptosis. The advances in fish immunoreaction upon encountering MCs will benefit the monitoring and prediction of fish health, helping to achieve an ecotoxicological goal and to ensure the sustainability of species. Future studies concerning MC-induced immunotoxicity should focus on adaptive immunity, the hormesis phenomenon and the synergistic effects of aquatic microbial pathogens.

Mechanistic Actions between Garcinia atroviridis Essential Oil and 2 Deoxy-d-glucose in Cultured PANC-1 Human Pancreatic Cancer Cells

Pancreatic cancer is an aggressive disease that progresses in a relatively symptom-free manner; thus, is difficult to detect and treat. Essential oil is reported to exhibit pharmacological properties, besides its common and well-known function as aromatherapy. Therefore, this study herein aimed to investigate the anti-proliferative effect of essential oil extracted from leaves of Garcinia atroviridis (EO-L) against PANC-1 human pancreatic cancer cell line. The cell growth inhibitory concentration at 50% (IC₅₀) and selective index (SI) values of EO-L analyses were determined as 78 µg/mL and 1.23, respectively. Combination index (CI) analysis revealed moderate synergism (CI values of 0.36 to 0.75) between EO-L and 2 deoxy-d-glucose (2-DG) treatments. The treatments of PANC-1 cells with EO-L, 2-DG and EOL+2DG showed evidence of depolarization of mitochondrial membrane potential, cell growth arrest and apoptosis. The molecular mechanism causing the anti-proliferative effect between EO-L and 2-DG is potentially through pronounced up-regulation of P53 (4.40-fold), HIF1α (1.92-fold), HK2 (2.88-fold) and down-regulation of CYP3A5 (0.11-fold), as supported by quantitative mRNA expression analysis. Collectively, the current data suggest that the combination of two anti-proliferative agents, EO-L and 2-DG, can potentially be explored as therapeutic treatments and as potentiating agents to conventional therapy against human pancreatic cancer.

Neutron reflectometry and NMR spectroscopy of full-length Bcl-2 protein reveal its membrane localization and conformation

B-cell lymphoma 2 (Bcl-2) proteins are the main regulators of mitochondrial apoptosis. Anti-apoptotic Bcl-2 proteins possess a hydrophobic tail-anchor enabling them to translocate to their target membrane and to shift into an active conformation where they inhibit pro-apoptotic Bcl-2 proteins to ensure cell survival. To address the unknown molecular basis of their cell-protecting functionality, we used intact human Bcl-2 protein natively residing at the mitochondrial outer membrane and applied neutron reflectometry and NMR spectroscopy. Here we show that the active full-length protein is entirely buried into its target membrane except for the regulatory flexible loop domain (FLD), which stretches into the aqueous exterior. The membrane location of Bcl-2 and its conformational state seems to be important for its cell-protecting activity, often infamously upregulated in cancers. Most likely, this situation enables the Bcl-2 protein to sequester pro-apoptotic Bcl-2 proteins at the membrane level while sensing cytosolic regulative signals via its FLD region.

Targeted apoptosis of macrophages and osteoclasts in arthritic joints is effective against advanced inflammatory arthritis

Insufficient apoptosis of inflammatory macrophages and osteoclasts (OCs) in rheumatoid arthritis (RA) joints contributes toward the persistent progression of joint inflammation and destruction. Here, we deliver celastrol (CEL) to selectively induce apoptosis of OCs and macrophages in arthritic joints, with enzyme-responsive nanoparticles (termed PRNPs) composed of RGD modified nanoparticles (termed RNPs) covered with cleavable PEG chains. CEL-loaded PRNPs (CEL-PRNPs) dually target OCs and inflammatory macrophages derived from patients with RA via an RGD-αvβ3 integrin interaction after PEG cleavage by matrix metalloprotease 9, leading to increased apoptosis of these cells. In an adjuvant-induced arthritis rat model, PRNPs have an arthritic joint-specific distribution and CEL-PRNPs efficiently reduce the number of OCs and inflammatory macrophages within these joints. Additionally, rats with advanced arthritis go into inflammatory remission with bone erosion repair and negligible side effects after CEL-PRNPs treatment. These findings indicate potential for targeting chemotherapy-induced apoptosis in the treatment of advanced inflammatory arthritis.

Developmental toxicity triggered by benzyl alcohol in the early stage of zebrafish embryos: Cardiovascular defects with inhibited liver formation and degenerated neurogenesis

Benzyl alcohol (BnOH) is an aromatic alcohol used worldwide as an excipient in foods, cosmetics, household products, and medications. Although BnOH is a bacteriostatic agent found in many parenteral preparations, this agent is responsible for precipitating the gasping syndrome in premature neonates. Increasing evidence of human exposure to BnOH and environmental contamination of BnOH requires a detailed toxicity assessment of this aromatic chemical. Few studies on the toxicity of BnOH have been reported on different animal models, but its developmental toxicity effects are not fully understood yet. Studies on the effects of BnOH on the specific endpoints of organ toxicity are rare. Thus, the present study aimed to examine the developmental toxicity effects of BnOH by using zebrafish (Danio rerio) embryo as a biological disease model. Four-hour post fertilization zebrafish embryos were exposed to BnOH for 72 h to assess BnOH toxicity on an ecological viewpoint. The median lethal concentrations of varying BnOH concentrations in zebrafish embryos were estimated. The embryonic toxicity induced by BnOH was revealed by the apoptosis in embryos and pathological alterations, such as increased mortality, inhibited hatching rate, and decreased somite number. Moreover, pericardial edema and string heartbeat were observed because of arrhythmia and cardiac malformation. The number of normal vessels in the head and trunk regions was remarkably reduced in transgenic zebrafish line Tg (Fli-1: EGFP). Morphological defects and yolk sac retention were related to the degenerated liver formation in Tg (Lfabp: dsRED). Furthermore, BnOH exposure led to the disruption of motor neuron axonal integrity and the alteration of the axon pattern in Tg (olig2: dsRED). In addition, the results exhibited the pathological effects of BnOH exposure on major organs. We believe that this study is the second to report the developmental organ toxicity of BnOH to zebrafish embryos. This study provides important information for further elucidating the mechanism of BnOH-induced developmental organ toxicity.

Berberine: A novel therapeutic strategy for cancer

Cancer, even currently, is one of the main reasons for mortality and morbidity, worldwide. In recent years, a great deal of effort has been made to find efficient therapeutic strategies for cancer, however, particularly with regards to side effects and the possibility of complete remission. Berberine (BBR) is a nature-driven phytochemical component originated from different plant groups such as Berberis vulgaris, Berberis aquifolium, and Berberis aristata. BBR is a well-known nutraceutical because of its wide range of pharmacological activities including anti-inflammatory, antidiabetic, antibacterial, antiparasitic, antidiarrheal, antihypertensive, hypolipidemic, and fungicide. In addition, it exhibits inhibitory effects on multiple types of cancers. In this review, we have elaborated on the anticancer effects of BBR through the regulation of different molecular pathways such as: inducing apoptosis, autophagy, arresting cell cycle, and inhibiting metastasis and invasion.

Effects of thermal stress-induced lead (Pb) toxicity on apoptotic cell death, inflammatory response, oxidative defense, and DNA methylation in zebrafish (Danio rerio) embryos

Lead (Pb) is a toxic environmental pollutant that is frequently present in effluents from urban, mining, and industrial sources. The combinatorial effects of heavy metal exposure and temperature in aquatic organisms have received considerable attention as heat stress occurs simultaneously in conjunction with several contaminants in a natural environment. In this study, we examined the potential effects of Pb exposure in conditions of thermal stress (34 °C) in zebrafish (Danio rerio) embryos. Thermal stress at 34 °C induced a dramatic decrease in the survival rate, although exposure to Pb at 26 °C decreased the survival rate of the embryos. Malformations, such as the curved body shape, were increased in response to exposure to a combination of Pb and heat stress. The combination of Pb and heat stress also caused a decrease in the heart rate. Moreover, Pb and high-temperature exposure induced the upregulation of SOD, CAT, TNF-α, IL-1β, p53, and BAX transcripts, and downregulation of Dnmt1 and Dnmt3b transcripts. Thermal stress enhanced transcriptional responses of eight indicator genes following Pb toxicity. The induction of cell death in response to combined exposures was also confirmed in the body of zebrafish by fluorescence intensity image analysis. These data indicated that thermal stress enhanced the poisonous effects of Pb exposure on antioxidant defense, inflammation, and apoptotic mechanisms. Transcriptional inhibition of DNA methylation-related genes might serve as a crucial factor contributing to the possibility of epigenetic adaptation by altering combined stress. We suggest that a careful evaluation of the potential effects of climate change (especially temperature) should be considered when investigating the toxic levels of metal pollution, such as Pb, in an aquatic environment.

Effect of acute exposure of saxitoxin on development of zebrafish embryos (Danio rerio)

As a type of cyanobacterial toxins, saxitoxin (STX) is receiving great interest due to its increasing presence in waterbodies. However, the underlying mechanism of STX-induced adverse effect is poorly understood. Here, we examined the developmental toxicity and molecular mechanism induced by STX using zebrafish embryos as an animal model. The embryonic toxicity induced by STX was demonstrated by inhibition of embryo hatching, increase in mortality rate, abnormal heart rate, abnormalities in embryo morphology as well as defects in angiogenesis and common cardinal vein remodeling. STX induced embryonic DNA damage and cell apoptosis, which would be alleviated by antioxidant N-acetyl-L-cysteine. Additionally, STX significantly increased reactive oxygen species level, catalase activity and malondialdehyde content and decreased the activity of superoxide dismutase and glutathione content. STX also promoted the expression of vascular development-related genes DLL4 and VEGFC, and inhibited VEGFA expression. Furthermore, STX altered the transcriptional regulation of apoptosis-related genes (BAX, BCL-2, P53 and CASPASE 3). Taken together, STX induced adverse effect on development of zebrafish embryos, which might be associated with oxidative stress-induced apoptosis.

Effects of combined stressors to cadmium and high temperature on antioxidant defense, apoptotic cell death, and DNA methylation in zebrafish (Danio rerio) embryos

Fish are frequently affected by environmental stressors, such as temperature changes and heavy metal exposure, in aquatic ecosystems. In this study, we evaluated the combined effects of cadmium (Cd) toxicity and temperature (rearing temperature of 26 °C and heat stress at 34 °C) on zebrafish (Danio rerio) embryos. The survival and heart rates of zebrafish embryos decreased at relatively high Cd concentrations of 0.07 and 0.1 mg L^-1. Abnormal morphology was induced by exposure to a combination of Cd toxicity and heat stress. The yolk sac edema size was not significantly different between the control- and Cd-treated groups. Cd exposure induced reactive oxygen species (ROS) production and cell death in the live zebrafish. High temperature (34 °C) triggered Cd-induced cell death and intracellular ROS production to a greater extent than the rearing temperature of 26 °C. Transcriptional levels of six genes-CAT, SOD, p53, BAX, Dnmt1, and Dnmt3b-were investigated. The mRNA expression of CAT and SOD, molecular indicators of oxidative stress, was increased significantly at 34 °C after Cd exposure. The mRNA expression of CAT was more sensitive to temperature than that of SOD in Cd-treated zebrafish. p53 and BAX, apoptosis-related genes, were upregulated upon combined exposure to high temperature and Cd. In addition, at 34 °C, the expression of Dnmt1 and Dnmt3b transcripts, markers of DNA methylation, was increased upon exposure of zebrafish to all concentrations of Cd. Overall, these results suggest that high temperature facilitates the potential role of Cd toxicity in the transcriptional regulation of genes involved in the antioxidant system, apoptosis, and DNA methylation.

Nodularin induced oxidative stress contributes to developmental toxicity in zebrafish embryos

Nodularin (NOD) is a kind of cyanobacterial toxins. It is of concern due to elicit severe genotoxicity in humans and animals. The comprehensive evaluation of NOD-induced adverse effects in living organisms is urgently needed. This study is aimed to report the developmental toxicity and molecular mechanism using zebrafish embryos exposed to NOD. The embryonic toxicity induced by NOD is demonstrated by inhibition of embryo hatching, increase in mortality rate, abnormal heart rate, embryonic malformation as well as defects in angiogenesis and common cardinal vein remodeling. NOD triggered a decreased rate of angiogenesis through inhibiting endothelial cells migration. NOD induced embryonic cell apoptosis and DNA damage, which can be alleviated by antioxidant N-acetyl-L-cysteine. NOD significantly caused oxidative damage as indicated by changes in reactive oxygen species, superoxide dismutase, catalase, glutathione and malondialdehyde. NOD also altered the expression of vascular development-genes (DLL4, CDH5, VEGFA, VEGFC) and apoptosis-related genes (BAX, BCL-2, P53, CASPASE 3). Taken together, NOD induced adverse effect on zebrafish embryos development, which may be associated with oxidative stress and apoptosis through the activation of P53-BAX/BCL-2-CASPASE 3-mediated pathway.

A novel recombinant expression and purification approach for the full-length anti-apoptotic membrane protein Bcl-2

Programmed cell death (apoptosis) is an essential mechanism in life that tightly regulates embryogenesis and removal of harmful cells. Besides an extrinsic pathway, an intrinsic (mitochondrial) apoptotic pathway exists where mitochondria are actively involved in cellular clearance in response to internal stress signals. Pro-apoptotic (death) and anti-apoptotic (survival) members of the B cell CLL/lymphoma-2 (Bcl-2) protein family meet at the mitochondrion's surface where they accurately regulate apoptosis. Overexpression of the anti-apoptotic Bcl-2 protein is a hallmark for many types of cancers and in particular for many treatment resistant tumors. Bcl-2 is a membrane protein residing in the mitochondrial outer membrane. Due to its typical membrane protein features including very limited solubility, it is difficult to express and to purify. Therefore, most biophysical and structural studies have used truncated, soluble versions. However, to understand its membrane-coupled function and structure, access to sufficient amount of full-length human Bcl-2 protein is a necessity. Here, we present a novel, E. coli based approach for expression and purification of preparative amounts of the full-length human isoform 2 of Bcl-2 (Bcl-2(2)), solubilized in detergent micelles, which allows for easy exchange of the detergent.

Induction of Apoptosis by Gluconasturtiin-Isothiocyanate (GNST-ITC) in Human Hepatocarcinoma HepG2 Cells and Human Breast Adenocarcinoma MCF-7 Cells

Gluconasturtiin, a glucosinolate present in watercress, is hydrolysed by myrosinase to form gluconasturtiin-isothiocyanate (GNST-ITC), which has potential chemopreventive effects; however, the underlying mechanisms of action have not been explored, mainly in human cell lines. The purpose of the study is to evaluate the cytotoxicity of GNST-ITC and to further assess its potential to induce apoptosis. GNST-ITC inhibited cell proliferation in both human hepatocarcinoma (HepG2) and human breast adenocarcinoma (MCF-7) cells with IC₅₀ values of 7.83 µM and 5.02 µM, respectively. Morphological changes as a result of GNST-ITC-induced apoptosis showed chromatin condensation, nuclear fragmentation, and membrane blebbing. Additionally, Annexin V assay showed proportion of cells in early and late apoptosis upon exposure to GNST-ITC in a time-dependent manner. To delineate the mechanism of apoptosis, cell cycle arrest and expression of caspases were studied. GNST-ITC induced a time-dependent G₂/M phase arrest, with reduction of 82% and 93% in HepG2 and MCF-7 cell lines, respectively. The same treatment also led to the subsequent expression of caspase-3/7 and -9 in both cells demonstrating mitochondrial-associated cell death. Collectively, these results reveal that GNST-ITC can inhibit cell proliferation and can induce cell death in HepG2 and MCF-7 cancer cells via apoptosis, highlighting its potential development as an anticancer agent.

Adverse effect of cylindrospermopsin on embryonic development in zebrafish (Danio rerio)

Eutrophication of freshwater bodies increases the occurrence of toxic cyanobacterial blooms. The cyanobacterial toxin cylindrospermopsin (CYN) is receiving great interest due to its increasing presence in waterbodies. However, the toxic effects of CYN on zebrafish development are poorly understood, especially the toxicological mechanism, which is still unclear. In this study, we examined the adverse effects of CYN on embryonic development in zebrafish. CYN (2-2000 nM) exposure decreased embryos survival rate, hatching rate, body length and eye size in a concentration-dependent manner and caused abnormalities in embryo morphology, including pericardial edema, spinal curvature, tail deformity, uninflated swim bladder, cardiac and vascular defects. CYN at concentrations of 20 nM or higher significantly increased ROS level and promoted cell apoptosis in zebrafish embryos. To preliminarily elucidate the potential mechanism of zebrafish developmental toxicity caused by CYN, we examined the expression of oxidative stress- and apoptotic-related genes. CYN could promote the expression of oxidative stress-related genes (SOD1, CAT and GPx1) and induce changes in transcriptional levels of apoptotic-related genes (p53, Bax and Bcl-2). Taken together, CYN induced adverse effects on zebrafish embryos development, which may associate with oxidative stress and apoptosis. These outcomes will advance our understanding of CYN toxicity, environmental problems and health hazards caused by climate changes and eutrophication.

Recent Advances in Apoptosis: THE Role of Hydrazones

The process of programmed cell death in higher eukaryotes (apoptosis), is generally characterized by distinct morphological characteristics and energy-dependent biochemical mechanisms. Apoptosis is considered as a vital component of various processes including normal cell turnover, proper development and functioning of the immune system, hormone-dependent atrophy, embryonic development and chemical-induced cell death. Apoptosis seems to play an important key role in the progression of several human diseases like Alzheimer's disease, Parkinson's disease and many types of cancer. Promotion of apoptosis may be a good approach for the prevention of cancer cell proliferation. In early studies, antitumor compounds have been found to induce the apoptotic process in tumor cells. On the other hand, several hydrazones were reported to have lower toxicity than hydrazides due to the blockage of -NH2 group. Therefore, the design of hydrazones that activate and promote apoptosis is an attractive strategy for the discovery and development of potential anticancer agents. The aim of this review is to provide a general overview of current knowledge and the connection between apoptosis and hydrazone. It is also the guide for the apoptotic activities of new hydrazone derivatives.

Chlorpyrifos and its metabolite modulates angiogenesis in the chorioallantoic membrane of chick embryo

Background Chlorpyrifos (CPF) is an organophosphate insecticide, acaricide, and miticide used primarily to control foliage and soilborne insect pests on a variety of food and feed crops. Since trace amounts of these compounds are found in water and food products, they easily enter into the organ system unnoticed. In the same way, the compound or its metabolite gets transmitted from the parent to the embryo mainly through blood vessels. Since blood vessels form the major route of transport, it is pertinent to study the effect of these compounds during angiogenesis. The effect of CPF and 3,5,6-trichloro-2-pyridinol (TCPy) on the angiogenesis of chick embryo was evaluated in the chorioallantoic membrane (CAM) using an ex vivo model. Methods Nine-day-old incubated eggs where inoculated with various doses of CPF and TCPy. After 48 h of incubation, the CAM layers were retrieved and analyzed using angiogenesis software to obtain the density of blood vessels. Histomorphometric studies were performed to measure the thickness of vessel walls. The expression of VEGF, VEGFR2, and N-cadherin genes responsible for angiogenesis were analyzed. Results The exposure to the parent compound CPF and its metabolite TCPy promoted angiogenesis in groups administered with lower concentration of the pesticide and its metabolite, whereas a decline in angiogenesis was observed at higher concentrations. These observations were made by analyzing the density, histomorphometry results, and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) results. The density, thickness, and lumen size of blood vessels in the groups with low concentration of CPF and TCPy were 28.34, 9 μm, and 30 μm, respectively, whereas in the groups with higher CPF and TCPy concentrations, they were 12, 3 μm, and 9 μm, respectively. Conclusions Hence, CPF and its metabolites interfere with angiogenesis in the CAM of chick embryos. Because of their estrogen-mimicking ability, pesticides are the prime etiological suspects of increasing alteration in blood vessel formation. These results may be of help in future studies on the effect of CPF in embryonic growth, wound healing, diabetes, and tumors.

Fine particulate matters induce apoptosis via the ATM/P53/CDK2 and mitochondria apoptosis pathway triggered by oxidative stress in rat and GC-2spd cell

Fine particulate matters (PM_2.5) have been associated with male reproductive toxicity because it can penetrate into the lung's gas-exchange region, and spread to the whole body via circulatory system. Previous studies have shown that PM_2.5 could induce DNA damage and apoptosis by reactive oxygen species (ROS). The aim of the present study is to determine the exact mechanism and role of apoptosis induced by PM_2.5 in spermatocyte cells. Male Sprague-Dawley (SD) rats were treated with normal saline (control group) or PM_2.5 with the doses of 1.8, 5.4 and 16.2 mg/kg bw. via intratracheal instillation every 3 days for 30 days. Mouse spermatocyte-derived cells (GC-2spd cells) were treated with various concentrations (0, 50, 100, 200 μg/mL) of PM_2.5 for 24 h. The results showed that exposure to PM_2.5 resulted in injury of testicular tissue and impaired mitochondria integrity in GC-2spd cells. Moreover, PM_2.5 induced DNA damage and apoptosis in GC-2spad cells via ROS generation, and the ATM/P53/CDK2 and mitochondria apoptosis pathway autophagy signal pathway were activated. N-Acetyl-L-cysteine (NAC), a well-known antioxidant, ameliorated DNA damage, and inhibited apoptosis. These findings demonstrated PM_2.5 might induce apoptosis via the mitochondrial apoptosis pathway through causing DNA damage resulting from oxidative stress, and finally caused spermatogenesis disorder.

Experimental data on novel Fe(III)-complexes containing phenanthroline derivatives for their anticancer properties

This dataset is related to the research article entitled "May iron(III) complexes containing phenanthroline derivatives as ligands be prospective anticancer agents?" [1]. It includes the characterization by UV-Vis absorption spectroscopy and magnetic techniques of a group of mixed ligand Fe(III) complexes bearing a tripodal aminophenolate ligand L^2-, H₂L = N,N-bis(2-hydroxy-3,5-dimethylbenzyl)-N-(2-pyridylmethyl)amine, and different aromatic bases (NN = 2,2'-bipyridine [Fe(L)(bipy)]PF₆ (1), 1,10-phenanthroline [Fe(L)(phen)]PF₆ (2), or a phenanthroline derivative co-ligand: [Fe(L)(amphen)]NO₃ (3), [Fe(L)(amphen)]PF₆ (3a), [Fe(L)(Clphen)]PF₆ (4), [Fe(L)(epoxyphen)]PF₆ (5) (where amphen = 1,10-phenanthroline-5-amine, epoxyphen = 5,6-epoxy-5,6-dihydro-1,10-phenanthroline, Clphen = 5-chloro-1,10-phenanthroline), as well as [Fe(L)(EtOH)]NO₃ (6), [Fe(phen)Cl₃] (7) and [Fe(amphen)Cl₃] (8). Data on their hydrolytic stability in physiological buffers is shown, as well as on their interaction with calf thymus DNA by spectroscopic tools. Additionally, the anticancer efficacy and the cellular death mechanisms activated in response to these drugs in HeLa, H1299 and MDA-MB-231 cells are provided.