Key morphological features of apoptosis may occur in the absence of internucleosomal DNA fragmentation

A systematic review of the cell death mechanisms in retinal pigment epithelium cells and photoreceptors after subretinal hemorrhage - Implications for treatment options

Humans rely on vision as their most important sense. This is accomplished by photoreceptors (PRs) in the retina that detect light but cannot function without the support and maintenance of the retinal pigment epithelium (RPE). In subretinal hemorrhage (SRH), blood accumulates between the neurosensory retina and the RPE or between the RPE and the choroid. Blood breakdown products subsequently damage PRs and the RPE and lead to poor vision and blindness. Hence, there is a high need for options to preserve the retina and visual functions. We conducted a systematic review of the literature in accordance with the PRISMA guidelines to identify the cell death mechanisms in RPE and PRs after SRH to deepen our understanding of the pathways involved. After screening 736 publications published until November 8, 2022, we identified 19 records that assessed cell death in PRs and/or RPE in experimental models of SRH. Among the different cell death mechanisms, apoptosis was the most widely investigated mechanism (11 records), followed by ferroptosis (4), whereas necroptosis, pyroptosis, and lysosome-dependent cell death were only assessed in one study each. We discuss different therapeutic options that were assessed in these studies, including the removal of the hematoma/iron chelation, cytoprotection, anti-inflammatory agents, and antioxidants. Further systematic investigations will be necessary to determine the exact cell death mechanisms after SRH with respect to different blood breakdown components, cell types, and time courses. This will form the basis for the development of novel treatment options for SRH.

Zinc: From Biological Functions to Therapeutic Potential

The trace element zinc (Zn) displays a wide range of biological functions. Zn ions control intercellular communication and intracellular events that maintain normal physiological processes. These effects are achieved through the modulation of several Zn-dependent proteins, including transcription factors and enzymes of key cell signaling pathways, namely those involved in proliferation, apoptosis, and antioxidant defenses. Efficient homeostatic systems carefully regulate intracellular Zn concentrations. However, perturbed Zn homeostasis has been implicated in the pathogenesis of several chronic human diseases, such as cancer, diabetes, depression, Wilson's disease, Alzheimer's disease, and other age-related diseases. This review focuses on Zn's roles in cell proliferation, survival/death, and DNA repair mechanisms, outlines some biological Zn targets, and addresses the therapeutic potential of Zn supplementation in some human diseases.

A Multimodal Approach to Quantify Chondrocyte Viability for Airway Tissue Engineering

OBJECTIVES/HYPOTHESIS

Partially decellularized tracheal scaffolds have emerged as a potential solution for long-segment tracheal defects. These grafts have exhibited regenerative capacity and the preservation of native mechanical properties resulting from the elimination of all highly immunogenic cell types while sparing weakly immunogenic cartilage. With partial decellularization, new considerations must be made about the viability of preserved chondrocytes. In this study, we propose a multimodal approach for quantifying chondrocyte viability for airway tissue engineering.

METHODS

Tracheal segments (5 mm) were harvested from C57BL/6 mice, and immediately stored in phosphate-buffered saline at -20°C (PBS-20) or biobanked via cryopreservation. Stored and control (fresh) tracheal grafts were implanted as syngeneic tracheal grafts (STG) for 3 months. STG was scanned with micro-computed tomography (μCT) in vivo. STG subjected to different conditions (fresh, PBS-20, or biobanked) were characterized with live/dead assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and von Kossa staining.

RESULTS

Live/dead assay detected higher chondrocyte viability in biobanked conditions compared to PBS-20. TUNEL staining indicated that storage conditions did not alter the proportion of apoptotic cells. Biobanking exhibited a lower calcification area than PBS-20 in 3-month post-implanted grafts. Higher radiographic density (Hounsfield units) measured by μCT correlated with more calcification within the tracheal cartilage.

CONCLUSIONS

We propose a strategy to assess chondrocyte viability that integrates with vivo imaging and histologic techniques, leveraging their respective strengths and weaknesses. These techniques will support the rational design of partially decellularized tracheal scaffolds.

LEVEL OF EVIDENCE

N/A Laryngoscope, 133:512-520, 2023.

Blocking Caspase-1/Gsdmd and Caspase-3/-8/Gsdme pyroptotic pathways rescues silicosis in mice

Millions of patients suffer from silicosis, but it remains an uncurable disease due to its unclear pathogenic mechanisms. Though the Nlrp3 inflammasome is involved in silicosis pathogenesis, inhibition of its classic downstream factors, Caspase-1 and Gsdmd, fails to block pyroptosis and cytokine release. To clarify the molecular mechanism of silicosis pathogenesis for new therapy, we examined samples from silicosis patients and genetic mouse models. We discovered an alternative pyroptotic pathway which requires cleavage of Gsdme by Caspases-3/8 in addition to Caspase-1/Gsdmd. Consistently, Gsdmd-/-Gsdme-/- mice showed markedly attenuated silicosis pathology, and Gsdmd-/-Gsdme-/- macrophages were resistant to silica-induced pyroptosis. Furthermore, we found that in addition to Caspase 1, Caspase-8 cleaved IL-1β in silicosis, explaining why Caspase-1-/- mice also suffered from silicosis. Finally, we found that inhibitors of Caspase-1, -3, -8 or an FDA approved drug, dimethyl fumarate, could dramatically alleviate silicosis pathology through blocking cleavage of Gsdmd and Gsdme. This study highlights that Caspase-1/Gsdmd and Caspase-3/8/Gsdme-dependent pyroptosis is essential for the development of silicosis, implicating new potential targets and drug for silicosis treatment.

Antioxidative, anti-inflammatory, and anticancer properties of the red biopigment extract from Monascus purpureus (MTCC 369)

In this study, the Monascus purpureus (MTCC 369) extracted biopigment produced by solid-state fermentation was evaluated for its therapeutic potential using human prostate LNCaP cells. Antioxidant efficacy of the red biopigment determined using 2,2 diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, and ferric reducing antioxidant power assays was found to be 53.16%, 86.27%, and 13.83%, respectively. In addition, expression studies of target gene superoxide dismutase 2 (SOD-2) showed that increasing concentrations (10-50 μg/ml) of the biopigment enhanced its expression from 0.91- to 1.905-fold. An inhibitory effect of 0.424-0.627-fold was observed in the expression of glutathione peroxidase (GPX) with a similar increase in biopigment concentration. Addition of quercetin (positive control) at 50 μg/ml led to 0.295-fold decrease in GPX expression. In contrast, the expression of SOD-2 increased by 1.026-fold in the presence of quercetin. The biopigment also showed an increased serological IL-10 expression (an anti-inflammatory agent) ranging from 1034.58 to 4657.89 pg/ml. Treatment of LNCaP cells with the red biopigment (10-100 μg/ml) resulted in significant (p < .05) reduction (upto 79.86%) in viability and 51.79%-89.86% reduction in cell metabolic activity. Fluorescent microscopy examination of red biopigment-treated cells showed significant inhibition of normal cellular morphology including condensed nuclei, membrane blebbing, and apoptotic bodies, thus confirming its cytotoxic potential. Results of this study revealed that the red biopigment has the potential to modulate the expression of antioxidative and anti-inflammatory markers in addition to being cytotoxic to the LNCaP cancer cells. PRACTICAL APPLICATIONS: These findings indicate that cell treatment with red biopigment has the potential to modulate anti-oxidative, pro-inflammatory and anti-inflammatory genes for therapeutic effects, which is further enhanced by its cytotoxic activity against cancer cells. Considering these cell-based observations, Monascus red biopigment has ample potential as a useful supplement to formulate therapeutic products that delay the development of inflammatory-related diseases and associated complications.

Fusion of apoptosis-related protein Cytochrome c with anti-HER-2 single-chain antibody targets the suppression of HER-2+ breast cancer

Cancer treatment has gradually developed from toxic chemotherapy to targeted therapy with fewer side effects. Approximately 30% of breast cancer patients overexpress human epidermal growth factor receptor 2 (HER-2). Previous studies have successfully produced single-chain antibodies (scFv) targeting HER-2+ breast cancer; however, scFv have poor stability, easy aggregation and a shorter half-life, which have no significant effect on targeting therapy. Moreover, scFv has been considered as a drug delivery platform that can kill target cells by effector molecules. However, the functional killing domains of immunotoxins are mainly derived from plant or bacterial toxins, which have a large molecular weight, low tissue permeability and severe side effects. To address these concerns, we designed several apoptotic immune molecules to replace exogenous toxins using endogenous apoptosis-related protein DNA fragmentation factor 40 (DFF40) and tandem-repeat Cytochrome c base on caspase-3 responsive peptide (DEVD). Our results suggest that DFF40 or Cytc fusion scFv specifically targets HER-2 overexpressing breast cancer cells (SK-BR-3 and BT-474) rather than HER-2 negative cells (MDA-MB-231 and MCF-7). Following cellular internalization, apoptosis-related proteins inhibited tumour activity by initiating endogenous apoptosis pathways, which significantly reduced immunogenicity and toxic side effects. Therefore, we suggest that immunoapoptotic molecules may become potential drugs for targeted immunotherapy of breast cancer.

Stability of proteins involved in initiation of DNA replication in UV damaged human cells

The protein stability of the initiation factors Orc2, Orc3, Orc4, and Cdc6 was analyzed after UV light exposure in two human cell lines. In the cell line with higher repair capacity, HEK 293, no changes in the cell cycle distribution or in the protein levels of the investigated factors were detected. In HeLa cells that are characterized by lower repair capacity, UV irradiation caused a reduction of the levels of Cdc6, Orc2 and Orc3, but not of Orc4 or triggered apoptosis. The appearance of the truncated 49 kDa form of Cdc6 suggested the involvement of the caspase pathway in the degradation of the proteins. Reduced protein levels of Cdc6 were detected in UV damaged HeLa cells in which the apoptotic process was blocked with the caspase inhibitor Z-VAD-fmk, indicating that the degradation of Cdc6 is mediated by the proteasome pathway instead. In the presence of caffeine, an inhibitor of the cell cycle checkpoint kinases, Cdc6 was stabilized, demonstrating that its degradation is controlled by the DNA damage cell cycle checkpoint. We conclude that in response to DNA damage, the activation of origins of replication can be prevented by the degradation of Cdc6, most likely through the proteasome pathway.

Guidelines for Regulated Cell Death Assays: A Systematic Summary, A Categorical Comparison, A Prospective

Over the past few years, the field of regulated cell death continues to expand and novel mechanisms that orchestrate multiple regulated cell death pathways are being unveiled. Meanwhile, researchers are focused on targeting these regulated pathways which are closely associated with various diseases for diagnosis, treatment, and prognosis. However, the complexity of the mechanisms and the difficulties of distinguishing among various regulated types of cell death make it harder to carry out the work and delay its progression. Here, we provide a systematic guideline for the fundamental detection and distinction of the major regulated cell death pathways following morphological, biochemical, and functional perspectives. Moreover, a comprehensive evaluation of different assay methods is critically reviewed, helping researchers to make a reliable selection from among the cell death assays. Also, we highlight the recent events that have demonstrated some novel regulated cell death processes, including newly reported biomarkers (e.g., non-coding RNA, exosomes, and proteins) and detection techniques.

A novel apoptosis probe, cyclic ApoPep-1, for in vivo imaging with multimodal applications in chronic inflammatory arthritis

Apoptosis plays an essential role in the pathophysiologic processes of rheumatoid arthritis. A molecular probe that allows spatiotemporal observation of apoptosis in vitro, in vivo, and ex vivo concomitantly would be useful to monitoring or predicting pathophysiologic stages. In this study we investigated whether cyclic apoptosis-targeting peptide-1 (_CApoPep-1) can be used as an apoptosis imaging probe in inflammatory arthritis. We tested the utility of _CApoPep-1 for detecting apoptotic immune cells in vitro and ex vivo using flow cytometry and immunofluorescence. The feasibility of visualizing and quantifying apoptosis using this probe was evaluated in a murine collagen-induced arthritis (CIA) model, especially after treatment. _CApoPep-1 peptide may successfully replace Annexin V for in vitro and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay for ex vivo in the measurement of apoptotic cells, thus function as a sensitive probe enough to be used clinically. In vivo imaging in CIA mice revealed that _CApoPep-1 had 42.9 times higher fluorescence intensity than Annexin V for apoptosis quantification. Furthermore, it may be used as an imaging probe for early detection of apoptotic response in situ after treatment. The _CApoPep-1 signal was mostly co-localized with the TUNEL signal (69.6% of TUNEL⁺ cells) in defined cell populations in joint tissues of CIA mice. These results demonstrate that _CApoPep-1 is sufficiently sensitive to be used as an apoptosis imaging probe for multipurpose applications which could detect the same target across in vitro, in vivo, to ex vivo in inflammatory arthritis.

A Reverse-Osmosis Model of Apoptotic Shrinkage

The standard theory of apoptotic volume decrease (AVD) posits activation of potassium and/or chloride channels, causing an efflux of ions and osmotic loss of water. However, in view of the multitude of possible channels that are known to support apoptosis, a model based on specific signaling to a channel presents certain problems. We propose another mechanism of apoptotic dehydration based on cytoskeletal compression. As is well known, cytoskeleton is not strong enough to expel a substantial amount of water against an osmotic gradient. It is possible, however, that an increase in intracellular pressure may cause an initial small efflux of water, and that will create a small concentration gradient of ions, favoring their exit. If the channels are open, some ions will exit the cell, relieving the osmotic gradient; in this way, the process will be able to continue. Calculations confirm the possibility of such a mechanism. An increase in membrane permeability for water or ions may also result in dehydration if accompanied even by a constant cytoskeletal pressure. We review the molecular processes that may lead to apoptotic dehydration in the context of this model.

Toxic effects of the Emamectin Benzoate exposure on cultured human bronchial epithelial (16HBE) cells

Pesticides pollution has caused serious environmental problems in recent years, and mounting evidence has shown that more and more insecticides have serious risk in human health. Emamectin Benzoate formally regarded as a highly safety insecticide based on its exclusive targets, but the cytotoxicity to human lung was ignored for a long time. In the present study, bioassay experiments were used to assess the toxicity of the Emamectin Benzoatein on human non-target cells including cell viability assay, DNA damage assay, flow cytometer assay and western blotting assay. The results indicated that Emamectin Benzoatecan cause the inhibition of the proliferation, cytochrome c release, activation of caspase-3/9 and increase Bax/Bcl-2 ratio, which means it induced the cytotoxicity on 16HBE cells associated with the mitochondrial apoptosis. Besides, the DNA damge caused by the Emamectin Benzoate suggest it has a potential genotoxic effect on human lung cells.

The impact of endothelial cell death in the brain and its role after stroke: A systematic review

The supply of oxygen and nutrients to the brain is vital for its function and requires a complex vascular network that, when disturbed, results in profound neurological dysfunction. As part of the pathology in stroke, endothelial cells die. As endothelial cell death affects the surrounding cellular environment and is a potential target for the treatment and prevention of neurological disorders, we have systematically reviewed important aspects of endothelial cell death with a particular focus on stroke. After screening 2876 publications published between January 1, 2010 and August 7, 2019, we identified 154 records to be included. We found that endothelial cell death occurs rapidly as well as later after the onset of stroke conditions. Among the different cell death mechanisms, apoptosis was the most widely investigated (92 records), followed by autophagy (20 records), while other, more recently defined mechanisms received less attention, such as lysosome-dependent cell death (2 records) and necroptosis (2 records). We also discuss the differential vulnerability of brain cells to injury after stroke and the role of endothelial cell death in the no-reflow phenomenon with a special focus on the microvasculature. Further investigation of the different cell death mechanisms using novel tools and biomarkers will greatly enhance our understanding of endothelial cell death. For this task, at least two markers/criteria are desirable to determine cell death subroutines according to the recommendations of the Nomenclature Committee on Cell Death.

Piperazine clubbed with 2-azetidinone derivatives suppresses proliferation, migration and induces apoptosis in human cervical cancer HeLa cells through oxidative stress mediated intrinsic mitochondrial pathway

Piperazine scaffolds or 2-azetidinone pharmacophores have been reported to show anti-cancer activities and apoptosis induction in different types of cancer cells. However, the mechanistic studies involve in induction of apoptosis addressing these two moieties for human cervical cancer cells remain uncertain. The present study emphasizes on the anti-proliferating properties and mechanism involved in induction of apoptosis for these structurally related azoles derivatives in HeLa cancer cells. 1-Phenylpiperazine clubbed with 2-azetidione derivatives (5a-5h) were synthesized, characterized using various spectroscopic techniques and evaluated for their in-vitro anti-proliferative activities and induction of apoptosis. Further, we also evaluated oxidative stress generated by these synthetic derivatives (5a-5h). Cell viability studies revealed that among all, the compound N-(3-chloro-2-(3-nitrophenyl)-4-oxoazetidin-1-yl)-2-(4-phenylpiperazin-1-yl) acetamide 5e remarkably inhibited the growth of HeLa cells in a concentration dependent manner having IC₅₀ value of 29.44 ± 1.46 µg/ml. Morphological changes, colonies suppression and inhibition of migration clearly showed the antineoplasicity in HeLa cells treated with 5e. Simultaneously, phosphatidylserine externalization, DNA fragmentation and cell-cycle arrest showed ongoing apoptosis in the HeLa cancer cells induced by compound 5e in concentration dependent manner. Additionally, generation of intracellular ROS along with the decrease in mitochondrial membrane potential supported that compound 5e caused oxidative stress resulting in apoptosis through mitochondria mediated pathway. Elevation in the level of cytochrome c and upregulation in expression of caspase-3 clearly indicated the involvement of the intrinsic pathway of programmed cell death. In brief; compound 5e could serve as a promising lead for the development of an effective antitumor agent.

The Inhibitory Effect of Cordycepin on the Proliferation of MCF-7 Breast Cancer Cells, and its Mechanism: An Investigation Using Network Pharmacology-Based Analysis

Cordyceps militaris is a well-known medicinal mushroom. It is non-toxic and has clinical health benefits including cancer inhibition. However, the anticancer effects of C. militaris cultured in brown rice on breast cancer have not yet been reported. In this study, we simultaneously investigated the anticancer effects of cordycepin and an extract of C. militaris cultured in brown rice on MCF-7 human breast cancer cells using a cell viability assay, cell staining with Hoechst 33342, and an image-based cytometric assay. The C. militaris concentrate exhibited significant MCF-7 cell inhibitory effects, and its IC50 value was 73.48 µg/mL. Cordycepin also exhibited significant MCF-7 cell inhibitory effects, and its IC50 value was 9.58 µM. We applied network pharmacological analysis to predict potential targets and pathways of cordycepin. The gene set enrichment analysis showed that the targets of cordycepin are mainly associated with the hedgehog signaling, apoptosis, p53 signaling, and estrogen signaling pathways. We further verified the predicted targets related to the apoptosis pathway using western blot analysis. The C. militaris concentrate and cordycepin exhibited the ability to induce apoptotic cell death by increasing the cleavage of caspase-7 -8, and -9, increasing the Bcl-2-associated X protein/ B-cell lymphoma 2 (Bax/Bcl-2) protein expression ratio, and decreasing the protein expression of X-linked inhibitor of apoptosis protein (XIAP) in MCF-7 cells. Consequently, the C. militaris concentrate and cordycepin exhibited significant anticancer effects through their ability to induce apoptosis in breast cancer cells.

Nutraceutic Potential of Two Allium Species and Their Distinctive Organosulfur Compounds: A Multi-Assay Evaluation

This study aimed to evaluate the biological activities of two Allium species (garlic and onion) as well as diallyl disulphide (DADS) and dipropyl disulphide (DPDS) as their representative bioactive compounds in a multi-assay experimental design. The genotoxic, antigenotoxic, and lifespan effects of garlic, onion, DADS, and DPDS were checked in Drosophila melanogaster and their cytotoxic, pro-apoptotic, and DNA-clastogenic activities were analyzed using HL60 tumoral cells. All compounds were non-genotoxic and antigenotoxic against H₂O₂-induced DNA damage with a positive dose-response effect and different inhibition percentages (the highest value: 95% for DADS) at all tested concentrations. Daily intake of Allium vegetables, DADS, or DPDS had no positive effects on flies' lifespan and health span. Garlic and DADS exerted the highest cytotoxic effects in a positive dose-dependent manner. Garlic and DADS exerted a DNA-internucleosomal fragmentation as an index of induced proapoptotic activity on HL60 cells. Allium vegetables and DADS were able to induce clastogenic strand breaks in the DNA of HL60 cells. This study showed the genomic safety of the assayed substances and their protective genetic effects against the hydrogen peroxide genotoxine. Long-term treatments during the whole life of the Drosophila genetic model were beneficial only at low-median concentrations. The chemo-preventive activity of garlic could be associated with its distinctive organosulfur DADS. We suggest that supplementary studies are needed to clarify the cell death pathway against garlic and DADS.

Evaluation of Ultra-Microscopic Changes and Proliferation of Apoptotic Glioblastoma Multiforme Cells Induced by Velogenic Strain of Newcastle Disease Virus AF2240

Aim:

Newcastle disease virus (NDV) is a member of genus Avulavirus within the family Paramyxoviridae. Interest of using NDV as an anticancer agent has arisen from its ability to kill tumor cells with limited toxicity to normal cells.

Methods:

In this investigation, the proliferation of brain tumor cell line, glioblastoma multiform (DBTRG.05MG) induced by NDV strain AF2240 was evaluated in-vitro, by using MTT proliferation assay. Furthermore, Cytological observations were studied using fluorescence microscopy and transmission electron microscopy, DNA laddering in agarose gel electrophoresis assay used to detect the mode of cell death and analysis of the cellular DNA content by flowcytometery.

Results:

MTT proliferation assay, Cytological observations using fluorescence microscopy and transmission electron microscopy show the anti-proliferation effect and apoptogenic features of NDV on DBTRG.05MG. Furthermore, analysis of the cellular DNA content showed that there was a loss of treated cells in all cell cycle phases (G1, S and G2/M) accompanied with increasing in sub-G1 region (apoptosis peak).

Conclusion:

It could be concluded that NDV strain AF2240 is a potent antitumor agent that induce apoptosis and its cytotoxicity increasing while increasing of time and virus titer.

Fenofibrate induces human hepatoma Hep3B cells apoptosis and necroptosis through inhibition of thioesterase domain of fatty acid synthase

This study demonstrated that fenofibrate, a lipid-lowering drug, induced a significant time-dependent cytotoxicity of hepatoma Hep3B cells. Hep3B cells are significantly more sensitive to cell killing by fenofibrate than hepatoma HepG2, lung cancer CH27 and oral cancer HSC-3 cells. From the result of docking simulation, fenofibrate can bind excellently to the thioesterase domain of fatty acid synthase (FASN) binding site as orlistat, a FASN inhibitor, acts. The fenofibrate-induced cell cytotoxicity was protected by addition of palmitate, indicating that the cytotoxic effect of fenofibrate is due to starvation of Hep3B cells by inhibiting the formation of end product in the FASN reaction. Inhibition of lipid metabolism-related proteins expression, such as proteins containing thioesterase domain and fatty acid transport proteins, was involved in the fenofibrate-induced Hep3B cell death. Fenofibrate caused S and G2/M cell cycle arrest by inducing cyclin A/Cdk2 and reducing cyclin D1 and E protein levels in Hep3B cells. The anti-tumor roles of fenofibrate on Hep3B cells by inducing apoptosis and necroptosis were dependent on the expression of Bcl-2/caspase family members and RIP1/RIP3 proteins, respectively. These results suggest that fenofibrate has an anti-cancer effect in Hep3B cells and inhibition of lipid metabolism may be involved in fenofibrate-induced Hep3B cells apoptosis and necroptosis.

Crosstalk between Fisetin-induced Apoptosis and Autophagy in Human Oral Squamous Cell Carcinoma

Fisetin (3,3-,4-,7-tetrahydroxyflavone), a naturally occurring flavonoid, has antioxidant, anti-inflammatory, and anticancer effects. Oral squamous cell carcinoma (OSCC) has a 5-year survival rate lower than that of most other carcinomas, and can create functional and aesthetic problems for the patient. New therapies for OSCC are necessary, and treatment using plant-derived natural substances has recently become a trend. It has been suggested that autophagy may play an important role in cancer therapy. Several studies demonstrated that autophagy inhibition enhances apoptotic cell death. Therefore, autophagy inhibition might be a promising therapeutic method against OSCC. Our results showed that fisetin induced apoptotic cell death in human tongue squamous cell line Ca9-22 could be enhanced by inhibition of autophagy. Thus, autophagy process in fisetin treated OSCC might presumed to play a role of pro-survival. The combination of fisetin and an effective autophagy inhibitor could be a potentially adjuvant and useful treatment for oral cancer.

The Impact of Moderate Chronic Hypoxia and Hyperoxia on the Level of Apoptotic and Autophagic Proteins in Myocardial Tissue

The redox imbalance and the consequent oxidative stress have been implicated in many pathological conditions, including cardiovascular diseases. The lack or the excess of O₂ supply can alter the redox balance. The aim of the present study was to understand the heart responses to prolonged hypoxia or hyperoxia and how such situations may activate survival mechanisms or trigger cell death. Seven-week-old Foxn1 mice were exposed to hypoxia (10% O₂), normoxia (21% O₂), or hyperoxia (30% O₂) for 28 days, then the heart tissue was excised and analyzed. The alterations in redox balance, housekeeping protein levels, and autophagic and apoptotic process regulation were studied. The D-ROM test demonstrated an increased oxidative stress in the hypoxic group compared to the hyperoxic group. The level of hypoxia inducible factor-1 (HIF-1α) was increased by hypoxia while HIF-2α was not affected by treatments. Chronic hypoxia activated the biochemical markers of autophagy, and we observed elevated levels of Beclin-1 while LC3B-II and p62 were constant. Nevertheless, we measured significantly enhanced number of TUNEL-positive cells and higher Bax/Bcl2 ratio in hyperoxia with respect to hypoxia. Surprisingly, our results revealed alterations in the level of housekeeping proteins. The expression of α-tubulin, total-actin, and GAPDH was increased in the hypoxic group while decreased in the hyperoxic group. These findings suggest that autophagy is induced in the heart under hypoxia, which may serve as a protective mechanism in response to enhanced oxidative stress. While prolonged hypoxia-induced autophagy leads to reduced heart apoptosis, low autophagic level in hyperoxia failed to prevent the excessive DNA fragmentation.

An Overlapping Cell Image Synthesis Method for Imbalance Data

DNA ploidy analysis of cells is an automation technique applied in pathological diagnosis. It is important for this technique to classify various nuclei images accurately. However, the lack of overlapping nuclei images in training data (imbalanced training data) results in low recognition rates of overlapping nuclei images. To solve this problem, a new method which synthesizes overlapping nuclei images with single-nuclei images is proposed. Firstly, sample selection is employed to make the synthesized samples representative. Secondly, random functions are used to control the rotation angles of the nucleus and the distance between the centroids of the nucleus, increasing the sample diversity. Then, the Lambert-Beer law is applied to reassign the pixels of overlapping parts, thus making the synthesized samples quite close to the real ones. Finally, all synthesized samples are added to the training sets for classifier training. The experimental results show that images synthesized by this method can solve the data set imbalance problem and improve the recognition rate of DNA ploidy analysis systems.

Both Granulocytic and Non-Granulocytic Blood Cells Are Affected in Patients with Severe Congenital Neutropenia and Their Non-Neutropenic Family Members: An Evaluation of Morphology, Function, and Cell Death

Objective:

To examine granulocytic and non-granulocytic cells in children with severe congenital neutropenia (SCN) and their non-neutropenic parents.

Materials and Methods:

Fifteen patients with SCN and 21 non-neutropenic parents were evaluated for a) CD95, CD95 ligand, annexin V, propidium iodide, cell cycle, and lymphocyte subsets by flow cytometry; b) rapid cell senescence (of leukocytes) by senescence-associated β-galactosidase stain; c) aggregation tests by aggregometer; d) in vitro bleeding time by PFA-100 instrument; e) mepacrine-labeled dense granule number of thrombocytes by fluorescence microscope; and f) hematomorphology by light and electron microscope. HAX1, ELANE, G6PC3, CSF3R, and JAGN1 mutations associated with SCN were studied in patients and several parents.

Results:

Significant increase in apoptosis and secondary necrosis in monocytes, lymphocytes, and granulocytes of the patients and parents was detected, irrespective of the mutation type. CD95 and CD95 ligand results implied that apoptosis was non-CD95-mediated. Leukocytes of 25%, 12.5%, and 0% of patients, parents, and controls showed rapid cell senescence. The cell cycle analysis testable in four cases showed G1 arrest and apoptosis in lymphocytes of three. The patients had HAX1 (n=6), ELANE (n=2), G6PC3 (n=2), and unidentified (n=5) mutations. The CD3, CD4, and NK lymphocytes were below normal levels in 16.6%, 8.3%, and 36.4% of the patients and in 0%, 0%, and 15.4% of the parents (controls: 0%, 0%, 5.6%). The thrombocytes aggregated at low rates, dense granule number/thrombocyte ratio was low, and in vitro bleeding time was prolonged in 37.5%-66.6% of patients and 33.3%-63.2% of parents (vs. 0% in controls). Under electron and/or light microscope, the neutrophils, monocytes, lymphocytes, and thrombocytes in the peripheral blood of both patients and parents were dysplastic and the bone marrow of patients revealed increased phagocytic activity, dysmegakaryopoiesis, and necrotic and apoptotic cells. Ultrastructurally, thrombocyte adhesion, aggregation, and release were inadequate.

Conclusion:

In cases of SCN, patients’ pluripotent hematopoietic stem cells and their non-neutropenic parents are both affected irrespective of the genetic defect.

Staurosporine-induced apoptotic water loss is cell- and attachment-specific

Apoptotic volume decrease (AVD) is a characteristic cell shrinkage observed during apoptosis. There are at least two known processes that may result in the AVD: exit of intracellular water and splitting of cells into smaller fragments. Although AVD has traditionally been attributed to water loss, direct evidence for that is often lacking. In this study, we quantified intracellular water in staurosporine-treated cells using a previously described optical microscopic technique that combines volume measurements with quantitative phase analysis. Water loss was observed in detached HeLa and in adherent MDCK but not in adherent HeLa cells. At the same time, adherent HeLa and adherent MDCK cells exhibited visually similar apoptotic morphology, including fragmentation and activation of caspase-3. Morphological changes and caspase activation were prevented by chloride channel blockers DIDS and NPPB in both adherent and suspended HeLa cells, while potassium channel blocker TEA was ineffective. We conclude that staurosporine-induced dehydration is not a universal cell response but depends on the cell type and substrate attachment and can only be judged by direct water measurements. The effects of potassium or chloride channel blockers do not always correlate with the AVD.

Radiomodulatory effects of Aloe vera on hepatic and renal tissues of X-ray irradiated mice

The present study was aimed to explore the protective role of Aloe vera gel extract against hepatic and renal damage caused by X-ray exposure to mice. Male balb/c mice were divided into four groups: control, Aloe vera gel extract [AV] (50 mg/ kg b.w on alternate days for 30 days), X-ray (2 Gy) and AV + X-ray. X-ray irradiation enhanced the serum levels of liver function indices and chromosomal abnormalities in liver. Kidney function markers were found to be deranged and were accompanied by reduced glomerular filtration rate indicating renal dysfunction. Irradiation caused histopathological and biochemical alterations in both tissues which was associated with enhanced reactive oxygen species (ROS), lipid peroxidation (LPO) levels, lactate dehydrogenase (LDH) activity and enhanced apoptosis as revealed by TUNEL assay and DNA fragmentation. The administration of Aloe vera gel extract to X-ray exposed animals significantly improved their hepatic and renal function parameters which were associated with a reduction in ROS/LPO levels, LDH activity and chromosomal abnormalities as compared to their irradiated counterparts. In vitro assays revealed effective radical scavenging ability of Aloe vera gel extract, which may be linked to its potential in exhibiting antioxidant effects in in vivo conditions. This data suggested that Aloe vera may serve to boost the antioxidant system, thus providing protection against hepatic and renal damage caused by X-ray.

Anti/genotoxic, longevity inductive, cytotoxic, and clastogenic-related bioactivities of tomato and lycopene

The aim of this study was to evaluate some biological activities of tomato as well as lycopene and to consider a new nutraceutic value for this fruit regarding to the protection against genetic damage and as a chemopreventive agent. Genotoxicity, DNA-protection against hydrogen peroxide, and lifespan properties of tomato and lycopene were assessed through wing spot test and longevity assay using the Drosophila in vivo model. Additionally, chemopreventive activity was investigated through cytotoxicity, DNA-fragmentation comet and annexin V FITC/PI assays using HL60 in vitro model. Results showed that: (i) tomato and lycopene are not genotoxic and protect against H₂ O₂ -induced damage; (ii) with respect to the lifespan, tomato and lycopene are harmless at the lowest concentration; (iii) tomato is cytotoxic in a dose-dependent manner, but not lycopene; (iv) tomato and lycopene do not induce internucleosomal DNA-fragmentation although they induce significant clastogenic activity at low level in the leukemia cells. To sum up, tomato is a good candidate to be considered as a nutraceutical substance. Furthermore, synergistic action among other components within tomato matrix could be the cause of the health effects observed in this vegetable, which are not fully explained by lycopene. Environ. Mol. Mutagen. 59:427-437, 2018. © 2018 Wiley Periodicals, Inc.

Effect of nerve injury on the number of dorsal root ganglion neurons and autotomy behavior in adult Bax-deficient mice

Background

The proapoptotic molecule BAX, plays an important role in mitochondrial apoptotic pathway. Dorsal root ganglion (DRG) neurons depend on neurotrophic factors for survival at early developmental stages. Withdrawal of neurotrophic factors will induce apoptosis in DRG neurons, but this type of cell death can be delayed or prevented in neonatal Bax knockout (KO) mice. In adult animals, evidence also shows that DRG neurons are less dependent upon neurotrophic factors for survival. However, little is known about the effect of Bax deletion on the survival of normal and denervated DRG neurons in adult mice.

Methods

A unilateral sciatic nerve transection was performed in adult Bax KO mice and wild-type (WT) littermates. Stereological method was employed to quantify the number of lumbar-5 DRG neurons 1 month post-surgery. Nerve injury-induced autotomy behavior was also examined on days 1, 3, and 7 post-surgery.

Results

There were significantly more neurons in contralateral DRGs of KO mice as compared with WT mice. The number of neurons was reduced in ipsilateral DRGs in both KO and WT mice. No changes in size distributions of DRG neuron profiles were detected before or after nerve injury. Injury-induced autotomy behavior developed much earlier and was more serious in KO mice.

Conclusion

Although postnatal death or loss of DRG neurons is partially prevented by Bax deletion, this effect cannot interfere with long-term nerve injury-induced neuronal loss. The exaggerated self-amputation behavior observed in the mutant mice indicates that Bax deficiency may enhance the development of spontaneous pain following nerve injury.

Potential genotoxic and cytotoxicity of emamectin benzoate in human normal liver cells

Pesticide residue inducing cancer-related health problems draw people more attention recently. Emamectin benzoate (EMB) has been widely used in agriculture around the world based on its specificity targets. Although potential risk and the molecular mechanism of EMB toxicity to human liver has not been well-characterized. Unlike well-reported toxicity upon central nervous system, potential genotoxic and cytotoxicity of EMB in human liver cell was ignored and very limited. In this study, we identify genotoxicity and cytotoxicity of EMB to human normal liver cells (QSG7701 cell line) in vitro. We demonstrate that EMB inhibited the viability of QSG7701 cells and induced the DNA damage. Established assays of cytotoxicity were performed to characterize the mechanism of EMB toxicity on QSG7701 cells. Typical chromatin condensation and DNA fragmentation indicated the apoptosis of QSG7701 cells induced by EMB. And the intracellular biochemical results demonstrated that EMB-enhanced apoptosis of QSG7701 cells concurrent with generated ROS, a loss of mitochondrial membrane potential, the cytochrome-c release, up regulate the Bax/Bcl-2 and the activation of caspase-9/-3. Our results of EMB induces the death of QSG7701 cells maybe via mitochondrial-mediated intrinsic apoptotic pathways would contribute to promote the awareness of EMB as an extensive used pesticide to human being effects and reveal the underlying mechanisms of potential genotoxic.

DNA analysis of cattle parasitic protozoan Tritrichomonas foetus after photodynamic therapy

Photodynamic therapy (PDT) is a modality of therapy that involves the activation of photosensitive substances and the generation of cytotoxic oxygen species and free radicals to promote the selective destruction of target tissues. This study analyzed the application of PDT to Tritrichomonas foetus, a scourged and etiological agent of bovine trichomoniasis, a sexually transmitted infectious disease. As it is an amitochondrial and aerotolerant protozoan, it produces energy under low O₂ tension via hydrogenosome. T. foetus from an axenic culture was incubated with photosensitizer tetrasulfonated aluminium phthalocyanine and then irradiated with a laser source (InGaAIP) at a density of 4.5Jcm^-2. The DNA integrity of the control and treated group parasites was analyzed by conventional gel electrophoresis and comet assay techniques. In previous results, morphological changes characterized by apoptotic cell death were observed after T. foetus was submitted to PDT treatment. In the treated groups, T. foetus DNA showed a higher concentration of small fragments, about 200pb, in gel electrophoresis after PDT. In the comet assay, the DNA tail percentage was significantly higher in the treated groups. These results demonstrate that PDT leads to DNA fragmentation with changes in nuclear morphology and apoptotic features.

Textural, Structural and Biological Evaluation of Hydroxyapatite Doped with Zinc at Low Concentrations

The present work was focused on the synthesis and characterization of hydroxyapatite doped with low concentrations of zinc (Zn:HAp) (0.01 < x_Zn < 0.05). The incorporation of low concentrations of Zn²⁺ ions in the hydroxyapatite (HAp) structure was achieved by co-precipitation method. The physico-chemical properties of the samples were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), zeta-potential, and DLS and N₂-BET measurements. The results obtained by XRD and FTIR studies demonstrated that doping hydroxyapatite with low concentrations of zinc leads to the formation of a hexagonal structure with lattice parameters characteristic to hydroxyapatite. The XRD studies have also shown that the crystallite size and lattice parameters of the unit cell depend on the substitutions of Ca²⁺ with Zn²⁺ in the apatitic structure. Moreover, the FTIR analysis revealed that the water content increases with the increase of zinc concentration. Furthermore, the Energy Dispersive X-ray Analysis (EDAX) and XPS analyses showed that the elements Ca, P, O, and Zn were found in all the Zn:HAp samples suggesting that the synthesized materials were zinc doped hydroxyapatite, Ca_10−xZn_x(PO₄)₆(OH), with 0.01 ≤ x_Zn ≤ 0.05. Antimicrobial assays on Staphylococcus aureus and Escherichia coli bacterial strains and HepG2 cell viability assay were carried out.

Plasmon-enhanced Raman spectroscopic metrics for in situ quantitative and dynamic assays of cell apoptosis and necrosis

Plasmon-enhanced Raman spectroscopic metrics were developed for in situ quantitative and dynamic assays of viable, apoptotic and necrotic cells.

Apoptosis and necrosis are distinct cell death processes related to many cellular pathways. In situ, quantitatively and dynamically monitoring such processes may provide vitally important information for cell studies. However, such a method still remains elusive, even though current immunochemical methodologies have developed extremely valuable tools. Herein, we demonstrate Raman spectroscopic metrics for validating and quantifying apoptotic and necrotic cells based on their distinct molecular vibrational fingerprints. It not only allows us to quantify apoptotic and necrotic cell populations in situ in adherent cell samples, but also to be capable of continuously monitoring the dynamical processes of apoptosis and necrosis at the same time in one sample. This method provides comparable results with the “gold standard” of flow cytometry, moreover, with several incomparable advantages. Our work offers a powerful new tool for cell apoptosis and necrosis assays and is expected to become a benchmark technology in biological and medical studies.

Tumor suppression effect of Solanum nigrum polysaccharide fraction on Breast cancer via immunomodulation

A polysaccharide fraction from Solanum nigrum, SN-ppF3 was shown previously to have an immunomodulatory activity where it could possibly be used to enhance the host immune response in fighting cancer. The non-toxic SN-ppF3 was fed orally to breast tumor bearing-mice with concentrations of 250 and 500mg/kg for 10days. During the treatment period, size of the tumor and weight of the mice were monitored. At the end of the treatment, blood, tumor, spleen and thymus were harvested for physiological and immunological analyses. After the treatment, the tumor volume and tumor weight were significantly inhibited by 65% and 40%, respectively. Based on the histological observation, the treatment of SN-ppF3 resulted in the disruption of tumor cells morphology. The increase in infiltrating T cells, NK cells and macrophages were observed in tumor tissues of the treated mice, which partly explained the higher apoptosis tumor cells observed in the treated mice. Moreover, the level of TNF-α, IFN-γ and IL-4 were elevated, while the level of IL-6 was decreased significantly, in serum of the treated mice. These results suggested that tumor suppression mechanisms observed in SN-ppF3-treated mice were most probably due through enhancing the host immune response.

Anti-proliferative and apoptosis-triggering potential of disulfiram and disulfiram-loaded polysorbate 80-stabilized PLGA nanoparticles on hepatocellular carcinoma Hep3B cell line

There is an emerging trend to restudy known drugs for their anti-cancer potential. One such anti-alcoholic drug, disulfiram, with significant anti-cancer potential was studied for its efficacy against Hep3B cell lines, an in vitro model of hepatocellular carcinoma. Simultaneously, we intended to study the effect of polysorbate 80-stabilized PLGA nanoparticles and its DSF-loaded counterpart. Cell and nuclear staining, comet assay, flow cytometry and Western blots were performed. Results suggest that cell proliferation was inhibited by DSF and its PLGA nanoparticles through cell cycle arrest, triggering activation of apoptotic pathways that culminates with cell death. DSF loaded nanoparticles when compared with free DSF, showed significantly lesser effect due to its sustained drug-releasing property, while empty nanoparticles showed negligible influence on Hep3B cells. Our results suggest that DSF alone contributes to cell death, while polysorbate 80-stabilized PLGA nanoparticles show sustained drug release patterns that would potentially lower dosage regimens.

Recombinant Multivalent EMMPRIN Extracellular Domain Induces U937 Human Leukemia Cell Apoptosis by Downregulation of Monocarboxylate Transporter 1 and Activation of Procaspase-9

This study was carried out to understand the effect of the recombinant multivalent extracellular matrix metalloproteinase inducer (EMMPRIN) extracellular domain, designated as rmEMMPRINex, on the apoptotic cell death of human leukemia U937 cells. Expression of monocarboxylate transporter 1 (MCT1) and caspase-9 in U937 treated with rmEMMPRINex was investigated in this study. Levels of membrane MCT1 and intracellular procaspase-9 were decreased in rmEMMPRINex-treated cells in comparison to controls. However, the expression of activated caspase-9 was undetectable. rmEMMPRINex also induced DNA fragmentation and apoptosis in U937 cells. Taken together, we concluded that interaction of rmEMMPRINex with U937 cells leads to inhibition of MCT1 membrane expression, intracellular activation of procaspase-9, followed by DNA fragmentation and apoptosis. This may contribute to the conceptual development of novel cancer drugs in the future.

Induction of caspase-9, biochemical assessment and morphological changes caused by apoptosis in cancer cells treated with goniothalamin extracted from Goniothalamus macrophyllus

Goniothalamin, a natural compound extracted from Goniothalamus sp. belonging to the Annonacae family, possesses anticancer properties towards several tumor cell lines. This study focused on apoptosis induction by goniothalamin (GTN) in the Hela cervical cancer cell line. Cell growth inhibition was measured by MTT assay and the IC50 value of goniothalamin was 3.2 ± 0.72 μg/ml. Morphological changes and biochemical processes associated with apoptosis were evident on phase contrast microscopy and fluorescence microscopy. DNA fragmentation, DNA damage, caspase-9 activation and a large increase in the sub-G1 and S cell cycle phases confirmed the occurrence of apoptosis in a time-dependent manner. It could be concluded that goniothalamin show a promising cytotoxicity effect against cervical cancer cells (Hela) and the cell death mode induced by goniothalamin was apoptosis.

Apoptosis of human tongue squamous cell carcinoma cell (CAL-27) induced by Lactobacillus sp. A-2 metabolites

OBJECTIVE

To study the effect of Lactobacillus sp. A-2 metabolites on viability of CAL-27 cells and apoptosis in CAL-27 cells.

METHODS

Lactobacillus sp. A-2 metabolites 1 and 2 (LM1 and LM2) were obtained by culturing Lactobacillus sp. A-2 in reconstituted whey medium and whey-inulin medium; the cultured CAL-27 cells were treated with different concentrations of LM1 and LM2 (0, 3, 6, 12, 24, 48 mg/mL) and assayed by methyl thiazolyltetrazolium (MTT) method; morphological changes of apoptotic cell were observed under fluorescence microscopy by acridine orange (Ao) fluorescent staining; flow cytometry method (FCM) and agarose gel electrophoresis were used to detect the apoptosis of CAL-27 cells treated LM1 and LM2.

RESULTS

The different concentrations of LM1 and LM2 could restrain the growth of CAL-27 cells, and in a dose-dependent manner; the apoptosis of CAL-27 cells was obviously induced and was time-dependent.

CONCLUSIONS

Viability of CAL-27 cells was inhibited by Lactobacillus sp. A-2 metabolites; Lactobacillus sp. A-2 metabolites could induce CAL-27 cells apoptosis; study on the bioactive compounds in the Lactobacillus sp. A-2 metabolites and their molecular mechanism is in progress.

Induction of apoptosis and antiproliferative activity of naringenin in human epidermoid carcinoma cell through ROS generation and cell cycle arrest

A natural predominant flavanone naringenin, especially abundant in citrus fruits, has a wide range of pharmacological activities. The search for antiproliferative agents that reduce skin carcinoma is a task of great importance. The objective of this study was to analyze the anti-proliferative and apoptotic mechanism of naringenin using MTT assay, DNA fragmentation, nuclear condensation, change in mitochondrial membrane potential, cell cycle kinetics and caspase-3 as biomarkers and to investigate the ability to induce reactive oxygen species (ROS) initiating apoptotic cascade in human epidermoid carcinoma A431 cells. Results showed that naringenin exposure significantly reduced the cell viability of A431 cells (p<0.01) with a concomitant increase in nuclear condensation and DNA fragmentation in a dose dependent manner. The intracellular ROS generation assay showed statistically significant (p<0.001) dose-related increment in ROS production for naringenin. It also caused naringenin-mediated epidermoid carcinoma apoptosis by inducing mitochondrial depolarization. Cell cycle study showed that naringenin induced cell cycle arrest in G0/G1 phase of cell cycle and caspase-3 analysis revealed a dose dependent increment in caspase-3 activity which led to cell apoptosis. This study confirms the efficacy of naringenin that lead to cell death in epidermoid carcinoma cells via inducing ROS generation, mitochondrial depolarization, nuclear condensation, DNA fragmentation, cell cycle arrest in G0/G1 phase and caspase-3 activation.

2,3,7,8-Tetrachlorodibenzo-p-dioxin alters steroid secretion but does not affect cell viability and the incidence of apoptosis in porcine luteinised granulosa cells

The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a by-product of human industrial activity, was found to affect ovarian steroidogenesis in animals, but the mechanism of its action is still unclear. The aims of the study were to examine the effect of TCDD on (1) progesterone (P4) and oestradiol (E2) production by granulosa cells isolated from medium (3-6 mm) and preovulatory (≥ 8 mm) porcine follicles, (2) the viability of the cells, and (3) the incidence of apoptosis. Porcine granulosa cells were cultured (48 h) with or without TCDD (100 pM, 100 nM). Steroid hormone concentrations in the medium were determined by radioimmunoassay. The viability of granulosa cells was tested spectrophotometrically (alamarBlue™ assay). Apoptosis was evaluated by flow cytometry using Annexin V and by TUNEL assay. The higher dose of TCDD (100 nM) significantly inhibited P4 and stimulated E2 production by luteinised granulosa cells isolated from medium follicles. The lower dose of TCDD (100 pM) significantly stimulated P4 and inhibited E2 secretion by the cells isolated from preovulatory follicles. None of the two TCDD doses affected cell viability or induced apoptosis in granulosa cells. In conclusion, TCDD directly affected steroid production by granulosa cells obtained from mature pigs, but the effect of TCDD was not due to its cytotoxicity.

Interaction of alveolar epithelial cells with CFP21, a mycobacterial cutinase-like enzyme

Mycobacterium tuberculosis (M. tb), an intracellular pathogen, has the ability to infect alveolar epithelial cells (AEC) also in addition to alveolar macrophages. The virulence of M. tb is attributed to proteins encoded by genomic regions of deletion (RD) and till date 16 such regions (RD1-RD16) have been identified. Culture filtrate protein 21 (CFP21), a RD2 secretory protein, is a cutinase-like enzyme that possesses esterase and lipolytic activity. It is hypothesized that CFP21 could be playing a role in M. tb virulence by disrupting the host cell integrity. In this study, recombinant CFP21 was expressed and purified. The in vitro exposure of type I (WI26) and type II (A549) AEC to CFP21 resulted in a significant decline in their cellular viability by inducing cell apoptosis. However, the cytotoxic effects were more pronounced in WI26 cells than in A549 cells. The analysis of immune responses in CFP21-treated AEC exhibited significant production of reactive oxygen species and anti-inflammatory cytokine TGF-β which indicated oxidative stress-mediated cell death. These results show that CFP21 could play an important role in M. tb pathogenesis by disrupting the host alveolar barrier and thereby facilitating mycobacterial dissemination.

Evaluation of meisoindigo, an indirubin derivative: in vitro antileukemic activity and in vivo pharmacokinetics

Meisoindigo has been a routine therapeutic agent in the clinical treatment of chronic myelogenous leukemia (CML) in China since the 1980s. In the present study, the in vitro antileukemic activity of meisoindigo was investigated in acute promyelocytic leukemia (APL) cells, acute myeloid leukemia (AML) cells, and myelomonocytic leukemia cells (NB4, NB4.007/6, HL-60 and U937) comprising both retinoic acid-sensitive and retinoic acid-resistant cells. We found that meisoindigo effectively inhibited the growth and/or proliferation of these four cell types at µM levels. The effects of meisoindigo in these cells are related to its proliferation inhibition and apoptosis induction, and are independent of cell cycle arrest, indicating that meisoindigo could be possible in the treatment of APL, AML and retinoic acid resistant APL. The in vivo pharmacokinetics of meisoindigo and its major circulatory metabolites in rat plasma were then investigated by a newly developed and validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The profiles of plasma concentration versus time were plotted and the relevant pharmacokinetic parameters were calculated for meisoindigo and its reductive metabolites. The plasma concentrations of meisoindigo after oral administration were much lower than the in vitro IC50s determined in the leukemic cells. The contradicting poor pharmacokinetic characteristics and the established clinical efficacy of meisoindigo could indicate the presence of active metabolites in vivo.

A novel manganese complex LMnAc selectively kills cancer cells by induction of ROS-triggered and mitochondrial-mediated cell death

We previously identified a novel synthesized metal compound, LMnAc ([L2Mn2(Ac)(H2O)2](Ac) (L=bis(2-pyridylmethyl) amino-2-propionic acid)). This compound exhibited significant inhibition on cancer cell proliferation and was more selective against cancer cells than was the popular chemotherapeutic reagent cisplatin. In this study, we further investigated the underlying molecular mechanisms of LMnAc-induced cancer cell death. We found that LMnAc achieved its selectivity against cancer cells through the transferrin-transferrin receptor system, which is highly expressed in tumor cells. LMnAc triggered cancer cells to commit autophagy and apoptosis, which was mediated by the mitochondrial pathway. Moreover, LMnAc disrupted mitochondrial function, resulting in mitochondrial membrane potential collapse and ATP reduction. In addition, LMnAc induced intracellular Ca(2+) overload and reactive oxygen species generation. Interestingly, its anticancer effect was significantly reduced following pretreatment with the antioxidant N-acetyl cysteine, indicating that reactive oxygen species triggered cell death. Altogether, our data suggest that LMnAc appears to be a selectively promising anticancer drug candidate.