Cellular responses to DNA damage

Double-stranded RNAs targeting inhibitor of apoptosis gene show no significant cross-species activity

RNA interference (RNAi) has become an integral part of mainstream research due to its versatility and ease of use. However, the potential nontarget effects associated with double-stranded RNAs (dsRNA) are poorly understood. To explore this, we used dsRNAs targeting the inhibitor of apoptosis (iap) gene from nine insect species and assayed their possible nontarget effects. For each assay, we used a control (dsRNA targeting the gene coding for green fluorescent protein, GFP) and a species-specific dsRNA targeting nine iap genes in insect species to evaluate target gene knockdown efficiency, apoptosis phenotype in cells and mortality in insects. Our results revealed that dsIAP efficiently knocks down iap gene expression and induces apoptosis phenotype and mortality in target insect species. In contrast, no significant knockdown of the iap gene expression, apoptosis phenotypes, or mortality were detected in cell lines developed from nontarget insects or nontarget insects treated with dsIAPs. Interestingly, even among closely related insects such as stink bugs, Nezara viridula, Halyomorpha halys, and Murgantia histrionica, with substantial sequence similarity among iap genes from these insects, no significant nontarget effects of dsIAP were observed under the conditions tested. These data demonstrate no significant nontarget effects for dsIAPs and suggest that the threat of nontarget effects of RNAi technology may not be substantial.

Live attenuated Edwardsiella ictaluri vaccines enhance the protective innate immune responses of channel catfish B cells

Edwardsiella ictaluri causes enteric septicemia of catfish. Our group developed two E. ictaluri live attenuated vaccines (LAVs). However, their effects on the innate functions of catfish B cells are still unexplored. We evaluated phagocytosis and killing of wild-type (WT) E. ictaluri opsonized with sera from vaccinated fish and the survival of B cells exposed to E. ictaluri strains. We assessed phagocytosis of the opsonized WT at 30 °C and 4 °C. B cells killed the internalized E. ictaluri opsonized with sera from vaccinated fish with LAVs more efficiently than other groups at 30 °C. However, catfish B cells were unable to destroy E. ictaluri at 4 °C. Furthermore, E. ictaluri opsonized with serum from fish exposed to WT induce apoptosis and decreased live B cells numbers. Results indicate that opsonization of E. ictaluri with sera from vaccinated fish enhanced phagocytosis and killing activity in B cells and inhibited apoptotic changes in the infected B cells.

Rheum officinale extract promotes the innate immunity of orange-spotted grouper (Epinephelus coioides) and exerts strong bactericidal activity against six aquatic pathogens

We investigated the antimicrobial properties and the effects of Rheum officinale extract (ROE) on nonspecific immune parameters of orange-spotted grouper (Epinephelus coioides) in vitro and in vivo. The in vitro analysis was conducted by treating grouper primary head kidney leukocytes with various concentrations of ROE. The phagocytic rate of the leukocytes was elevated in a dose-dependent manner from 0.01 to 0.1 mg/ml, but decreased with higher concentrations of ROE (0.5 and 1.0 mg/ml). The production of reactive oxygen species (ROS) was strongly enhanced in a dose-dependent manner by treatment with ROE doses of 0.1-10.0 mg/ml. However, morphological changes (e.g., rounding and shrinkage of cells, chromatin condensation, fragmentation, and appearance of apoptotic bodies) were observed in the leukocytes after incubation with higher concentrations of ROE (1.0 and 10.0 mg/ml). A 28-day feeding trial was performed to assess the impact of dietary administration of ROE on grouper innate immunity parameters. Fish were fed with feed supplemented with 0, 0.1, 1.0, or 5.0 g ROE per kg of feed. The phagocytic activity of the animals' leukocytes was significantly elevated in all ROE-fed groups on day 1 and in groups fed with ROE at 0.1 or 1.0 g/kg on day 14. Production of ROS was substantially increased on day 1 in fish fed with ROE at 1.0 and 5.0 g/kg, but decreased steadily later on. The ability to generate ROS increased steadily until day 7 in fish fed the lowest concentration of ROE (0.1 mg/ml), but decreased thereafter. ROE showed excellent antibacterial activity against six pathogens of aquatic animals: Vibrio parahaemolyticus, V. vulnificus, V. alginolyticus, V. carchariae, Aeromonas hydrophila, and Edwardsiella tarda. The minimum inhibitory and bactericidal concentrations of measured ROE-derived anthraquinones were 10.57-84.53 μg/ml and 10.57-169.05 μg/ml, respectively.

JNK signaling in Drosophila immunity and homeostasis

As members of the mitogen-activated protein kinase (MAPK) family, the c-Jun N-terminal kinases (JNKs) regulate cell responses to a wide range of extrinsic and intrinsic insults, including irradiation, reactive oxygen species (ROS), DNA damage, heat, bacterial antigens, and inflammatory cytokines. Particularly, JNK signaling regulates and promotes many important physiological processes that influence metabolic and tissue homeostasis, cell death/survival, and cell damage repair and ultimately impacts the lifespan of an organism. This diverse functionality causes a variety of tissue-specific and context-specific cellular responses, mediated by various cross talks between JNK and other cellular signaling pathways. Thus, highlighting its significance as a determinant of stress responses, JNK loss-of-function mutations have been implicated in a multitude of pathologies, including neurodegenerative diseases, diabetes, and cancer. Because JNK functions are specified in a context-dependent manner and can greatly vary, the underlying causes for these different outcomes remain largely unresolved despite the gained knowledge of many regulatory roles of JNK signaling during the past two decades. In Drosophila melanogaster, JNK signaling is conserved and required for immune responses, as well as the development for morphogenetic processes (embryonic dorsal closure and thorax closure). Therefore, Drosophila innate immunity provides the ideal model to understand the complex mechanisms underlying JNK activation and regulation. In the following, we review studies in Drosophila that highlight several mechanisms by which JNK signaling influences immunity and homeostasis.

Good Cop, Bad Cop: Defining the Roles of Δ40p53 in Cancer and Aging

The tumour suppressor p53 is essential for maintaining DNA integrity, and plays a major role in cellular senescence and aging. Understanding the mechanisms that contribute to p53 dysfunction can uncover novel possibilities for improving cancer therapies and diagnosis, as well as cognitive decline associated with aging. In recent years, the complexity of p53 signalling has become increasingly apparent owing to the discovery of the p53 isoforms. These isoforms play important roles in regulating cell growth and turnover in response to different stressors, depending on the cellular context. In this review, we focus on Δ40p53, an N-terminally truncated p53 isoform. Δ40p53 can alter p53 target gene expression in both a positive and negative manner, modulating the biological outcome of p53 activation; it also functions independently of p53. Therefore, proper control of the Δ40p53: p53 ratio is essential for normal cell growth, aging, and responses to cancer therapy. Defining the contexts and the mechanisms by which Δ40p53 behaves as a "good cop or bad cop" is critical if we are to target this isoform therapeutically.

Modulatory role of dietary Thymus vulgaris essential oil and Bacillus subtilis against thiamethoxam-induced hepatorenal damage, oxidative stress, and immunotoxicity in African catfish (Clarias garipenus)

Thiamethoxam (TMX) is a widely used neonicotinoid insecticide for its effective potential for controlling insects from the agricultural field, which might induce toxicity to the aquatic biota. In this study, the role of the probiotic Bacillus subtilis (BS) and a phytogenic oil extract of Thymus vulgaris essential oil (TVEO) in the modulation of thiamethoxam (TMX)-induced hepatorenal damage, oxidative stress, and immunotoxicity in African catfish (Clarias garipenus) has been evaluated. Fish were subjected to TMX (5 mg L^-1) and fed with a diet either supplemented with BS (1000 ppm) or TVEO (500 ppm). The experiment lasted for 1 month. By the end of the experiment, blood was sampled for biochemical analysis and fish organs and tissues were collected for histopathological and immunohistochemical examinations. Results showed a substantial increase of serum markers of hepatorenal damage such as the activities of aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) and levels of blood urea nitrogen (BUN) and creatinine with an obvious decrease of serum protein levels in the TMX-intoxicated group. Also, there was a considerable increase in malondialdehyde (MDA) levels and glutathione-S-transferase (GST) activity. TMX remarkably suppressed serum lysozyme activity, respiratory burst activity, and phagocytosis with a conspicuous elevation of the levels of interleukins (interleukin-1 beta (IL-1β) and interleukin-6 IL-6). The histopathological findings showed that TMX induced degenerative changes and necrosis in the gills, liver, head kidneys, and spleen of the intoxicated fish. Significant alterations of frequency, size, and area percentage of melanomacrophage centers (MMCs), decreased splenocyte proliferation, and increased number of caspase-3 immunopositive cells were also observed. Contrariwise, the concurrent supplementation of either BS or TVEO in the diets of catfish partially mitigated both the histopathological and histomorphometric lesions of the examined tissues. Correspondingly, they improved the counts of proliferating cell nuclear antigen (PCNA) and caspase-3 immunopositive splenocytes. In conclusion, the co-administration of either BS or TVEO in catfish diets partially diminished the toxic impacts of TMX. Nonetheless, the inclusion of TVEO in the diets of catfish elicited better protection than BS against TMX-induced toxicity in response to its potential anti-inflammatory, antioxidant, anti-apoptotic, and immune-stimulant effects.

Ultrasensitive monitoring of DNA damage associated with free radicals exposure using dynamic carbon nanotubes bridged interdigitated electrode array

There are currently increasingly concerns over DNA damage related to free radicals due to their vital roles in human health, especially high-performance detection method. Herein, we report an ultra- sensitive monitoring of DNA damage associated with free radicals exposure using interdigitated electrode (IDE) array for the first time. The proposed IDE array was equipped with DNA-wrapped carbon nanotube-based bridges, which utilized the DNA damage mechanism due to the free radicals' attack and the efficient electrical detection nature of the interdigitated electrode. Experiments have been performed, and the results showed the device's capability for detecting DNA damage induced by multiple free radicals generated from different sources, including the Fenton reaction, UV radiation and cigarette smoke, showing the promising ability for DNA damage detection. In addition, the carbon nanotubes bridge-based interdigitated electrode sensor enabled different levels of sensing of DNA damage with great sensitivity and a wide detection range. It was illustrated that the ultrasensitive detection of free radicals generated from ultraviolet radiation (15 min - 125 min), cigarette smoke tar (1 μg/mL to 10 μg/mL) and Fenton reaction under different concentration of H₂O₂ (2.5 pM - 100 pM), have been detected successfully. Typically, the IDE array supports further performance improvement for the electrochemical detection in an ultrasensitive and high throughput route.

Apoptosis Exerts a Vital Role in the Treatment of Colitis-Associated Cancer by Herbal Medicine

Colitis-associated cancer (CAC) is known as inflammatory bowel disease (IBD)-developed colorectal cancer, the pathogenesis of which involves the occurrence of apoptosis. Western drugs clinically applied to CAC are often single-targeted and exert many adverse reactions after long-term administration, so it is urgent to develop new drugs for the treatment of CAC. Herbal medicines commonly have multiple components with multiple targets, and most of them are low-toxicity. Some herbal medicines have been reported to ameliorate CAC through inducing apoptosis, but there is still a lack of systematic review. In this work, we reviewed articles published in Sci Finder, Web of Science, PubMed, Google Scholar, CNKI, and other databases in recent years by setting the keywords as apoptosis in combination with colitis-associated cancer. We summarized the herbal medicine extracts or their compounds that can prevent CAC by modulating apoptosis and analyzed the mechanism of action. The results show the following. (1) Herbal medicines regulate both the mitochondrial apoptosis pathway and death receptor apoptosis pathway. (2) Herbal medicines modulate the above two apoptotic pathways by affecting signal transductions of IL-6/STAT3, MAPK/NF-κ B, Oxidative stress, Non-canonical TGF-β1, WNT/β-catenin, and Cell cycle, thereby ameliorating CAC. We conclude that following. (1) Studies on the role of herbal medicine in regulating apoptosis through the Ras/Raf/ERK, WNT/β-catenin, and Cell cycle pathways have not yet been carried out in sufficient depth. (2) The active constituents of reported anti-CAC herbal medicine mainly include polyphenols, terpenoids, and saccharide. Also, we identified other herbal medicines with the constituents mentioned above as their main components, aiming to provide a reference for the clinical use of herbal medicine in the treatment of CAC. (3) New dosage forms can be utilized to elevate the targeting and reduce the toxicity of herbal medicine.

Thymoquinone is a protective agent that reduces the negative effects of doxorubicin in rat testis

BACKGROUND

Doxorubicin (DOX) is used for treatment of many cancer types. Thymoquinone (THQ) is a powerful antioxidant agent used for reducing side effects of several drugs. The aim of this study is to determine possible therapeutic effects of THQ on doxorubicin-induced testicular toxicity in rats.

METHODS

Rats were divided into five groups (n = 8): control, THQ, olive oil, DOX (a single dose of 15 mg/kg intraperitoneally (i.p.) on seventh day of the experiment), and DOX + THQ (10 mg/kg THQ per day and 15 mg/kg DOX i.p. on seventh day). Animals were euthanized, and testis tissues were evaluated histopathologically. Caspase 3 and HSP90 immunostaining were performed to determine the expression levels of these proteins among groups. Terminal deoxynucleotidyl transferase 2'-deoxyuridine, 5'-triphosphate nick-end labeling method was used for evaluation of apoptotic index. Moreover, serum testosterone levels and total antioxidant status (TAS) and total oxidant status (TOS) in testicular tissue were measured by ELISA assay.

RESULTS

The DOX group had histopathological deterioration compared to the control group. There was an increase in apoptotic index, caspase 3 and HSP90 expressions in the DOX group. While TAS level of the DOX group decreased, TOS level increased when compared with the other groups. Serum testosterone levels in the DOX group decreased compared to the control group. However, there was improvement in testicular tissue in DOX + THQ group compared to the DOX group. There was a decrease in apoptotic index, caspase 3, and HSP90 expressions in DOX + THQ group compared to the DOX group. Testosterone level of DOX + THQ significantly increased compared to the DOX group.

CONCLUSION

We suggest that THQ can be used as a protective agent to reduce the toxic effects of DOX.

A Systematic Review of the Mechanisms Underlying Treatment of Gastric Precancerous Lesions by Traditional Chinese Medicine

Gastric precancerous lesions (GPLs) are an essential precursor in the occurrence and development of gastric cancer, known to be one of the most common and lethal cancers worldwide. Traditional Chinese medicine (TCM) has a positive prospect for the prevention and therapy of GPL owing to several advantages including a definite curative effect, fewer side effects compared to other treatments, multiple components, and holistic regulation. Despite these characteristic advantages, the mechanisms of TCM in treating GPL have not been fully elucidated. In this review, we summarize the current knowledge with respect to herbal formulations and the therapeutic mechanisms of TCM active ingredients for GPL. This paper elaborates on the mechanisms of TCM underlying the prevention and treatment of GPL, specifically those that are linked to anti-H. pylori, anti-inflammation, antiproliferation, proapoptotic, antioxidation, antiglycolytic, and antiangiogenesis effects.

A real-time, bioluminescent annexin V assay for the assessment of apoptosis

Apoptosis is an important and necessary cell death program which promotes homeostasis and organismal survival. When dysregulated, however, it can lead to a myriad of pathologies from neurodegenerative diseases to cancer. Apoptosis is therefore the subject of intense study aimed at dissecting its pathways and molecular mechanisms. Although many assay methods exist for confirming whether an apoptotic response has occurred in vitro, most methods are destructive and involve laborious operator effort or specialized instrumentation. Here we describe a real-time, no-wash, microplate method which utilizes recombinant annexin V fusion proteins containing evolved binary subunits of NanoBiT™ luciferase. The fusion proteins, a time-released enzymatic substrate, a necrosis detection dye and exogenous calcium ions are delivered via an optimized and physiologically inert reagent directly to cells in culture at the time of treatment or dosing. Luminescent signals proportional to phosphatidylserine (PS) exposure and fluorescent signals generated as a result of loss of membrane integrity are then collected using a standard multimode plate reader at scheduled intervals over the exposure. The resulting luminescent and fluorescent data are then used to define the kinetics and magnitude of an apoptotic response. This study details our efforts to develop, characterize, and demonstrate the features of the assay by providing relevant examples from diverse cell models for programmed cell death.

The potential health benefits of the isoflavone glycoside genistin

Genistin is a type of isoflavone glycoside and has a broad range of health benefits. It is found in a variety of dietary plants, such as soybean, kudzu (Japanese arrowroot), and other plant-based products. Genistin has been described to have several beneficial health impacts, such as decreasing the risk of osteoporosis and post-menopausal symptoms, as well as anti-cancer, anti-oxidative, cardioprotective, anti-apoptotic, neuroprotective, hepatoprotective, and anti-microbial activities. It may also assist individuals with metabolic syndrome. This review summarizes some of the molecular impacts and prospective roles of genistin in maintaining and treatment of health disorders. The review could help to develop novel genistin medicine with significant health benefits for application in the nutraceutical and pharmaceutical fields.

Pro-apoptotic and pro-proliferation functions of the JNK pathway of Drosophila: roles in cell competition, tumorigenesis and regeneration

The Jun N-terminal kinase (JNK) is a member of the mitogen-activated protein kinase family. It appears to be conserved in all animal species where it regulates important physiological functions involved in apoptosis, cell migration, cell proliferation and regeneration. In this review, we focus on the functions of JNK in Drosophila imaginal discs, where it has been reported that it can induce both cell death and cell proliferation. We discuss this apparent paradox in the light of recent findings and propose that the pro-apoptotic and the pro-proliferative functions are intrinsic properties of JNK activity. Whether one function or another is predominant depends on the cellular context.

Mechanisms for the transition from physiological to pathological cardiac hypertrophy

The heart is capable of responding to stressful situations by increasing muscle mass, which is broadly defined as cardiac hypertrophy. This phenomenon minimizes ventricular wall stress for the heart undergoing a greater than normal workload. At initial stages, cardiac hypertrophy is associated with normal or enhanced cardiac function and is considered to be adaptive or physiological; however, at later stages, if the stimulus is not removed, it is associated with contractile dysfunction and is termed as pathological cardiac hypertrophy. It is during physiological cardiac hypertrophy where the function of subcellular organelles, including the sarcolemma, sarcoplasmic reticulum, mitochondria, and myofibrils, may be upregulated, while pathological cardiac hypertrophy is associated with downregulation of these subcellular activities. The transition of physiological cardiac hypertrophy to pathological cardiac hypertrophy may be due to the reduction in blood supply to hypertrophied myocardium as a consequence of reduced capillary density. Oxidative stress, inflammatory processes, Ca2+-handling abnormalities, and apoptosis in cardiomyocytes are suggested to play a critical role in the depression of contractile function during the development of pathological hypertrophy.

Apoptotic Bodies: Particular Extracellular Vesicles Involved in Intercellular Communication

In the last decade, a new method of cell-cell communication mediated by membranous extracellular vesicles (EVs) has emerged. EVs, including exosomes, microvesicles, and apoptotic bodies (ApoBDs), represent a new and important topic, because they are a means of communication between cells and they can also be involved in removing cellular contents. EVs are characterized by differences in size, origin, and content and different types have different functions. They appear as membranous sacs released by a variety of cells, in different physiological and patho-physiological conditions. Intringuingly, exosomes and microvesicles are a potent source of genetic information carriers between different cell types both within a species and even across a species barrier. New, and therefore still relatively poorly known vesicles are apoptotic bodies, on which numerous in-depth studies are needed in order to understand their role and possible function. In this review we would like to analyze their morpho-functional characteristics.

The functions and targets of miR-212 as a potential biomarker of cancer diagnosis and therapy

Cancer is a major health problem worldwide. An increasing number of researchers are studying the diagnosis, therapy and mechanisms underlying the development and progression of cancer. The study of noncoding RNA has attracted a lot of attention in recent years. It was found that frequent alterations of miRNA expression not only have various functions in cancer but also that miRNAs can act as clinical markers of diagnosis, stage and progression of cancer. MiR-212 is an important example of miRNAs involved in cancer. According to recent studies, miR-212 may serve as an oncogene or tumour suppressor by influencing different targets or pathways during the oncogenesis and the development and metastasis of cancer. Its deregulation may serve as a marker for the diagnosis or prognosis of cancer. In addition, it was recently reported that miR-212 was related to the sensitivity or resistance of cancer cells to chemotherapy or radiotherapy. Here, we summarize the current understanding of miR-212 functions in cancer by describing the relevant signalling pathways and targets. The role of miR-212 as a biomarker and its therapeutic potential in cancer is also described. The aim of this review was to identify new methods for the diagnosis and treatment of human cancers.

The mechanisms and cell signaling pathways of programmed cell death in the bacterial world

While programmed cell death was once thought to be exclusive to eukaryotic cells, there are now abundant examples of well regulated cell death mechanisms in bacteria. The mechanisms by which bacteria undergo programmed cell death are diverse, and range from the use of toxin-antitoxin systems, to prophage-driven cell lysis. Moreover, some bacteria have learned how to coopt programmed cell death systems in competing bacteria. Interestingly, many of the potential reasons as to why bacteria undergo programmed cell death may parallel those observed in eukaryotic cells, and may be altruistic in nature. These include protection against infection, recycling of nutrients, to ensure correct morphological development, and in response to stressors. In the following chapter, we discuss the molecular and signaling mechanisms by which bacteria undergo programmed cell death. We conclude by discussing the current open questions in this expanding field.

Edwardsiella ictaluri evpP is required for colonisation of channel catfish ovary cells and necrosis in anterior kidney macrophages

Edwardsiella ictaluri is a Gram-negative facultative anaerobe that can survive inside channel catfish phagocytes. E. ictaluri can orchestrate Type VI Secretion System (T6SS) for survival in catfish macrophages. evpP encodes one of the T6SS translocated effector proteins. However, the role of evpP in E. ictaluri is still unexplored. In this work, we constructed an E. ictaluri evpP mutant (EiΔevpP) and assessed its survival under complement and oxidative stress. Persistence of EiΔevpP in catfish as well as attachment and invasion in catfish macrophage and ovary cells were determined. Further, virulence of EiΔevpP in catfish and apoptosis it caused in macrophages were explored. EiΔevpP behaved same as wild type (EiWT) under complement and oxidative stress in complex media, whereas oxidative stress affected mutant's survival significantly in minimal media (p < .05). Persistence of EiΔevpP in live catfish and uptake and survival inside peritoneal macrophages were similar. The attachment and invasion capabilities of EiΔevpP in catfish ovary cells were significantly less than that of EiWT (p < .05). Although EiΔevpP showed reduced attenuation in catfish, causing decreased catfish mortality compared with EiWT (44.73% vs. 67.53%), this difference was not significant. The apoptosis assay using anterior kidney macrophages indicated that the number of live macrophages exposed to EiΔevpP was significantly higher compared with EiWT exposed macrophages at 24-hr post-treatment (p < .05). However, there were no significant differences in the early and late apoptosis. Remarkably, necrosis in EiΔevpP exposed macrophages was significantly less than that of EiWT exposed macrophages at 24 hr (p < .05). Our results demonstrated that evpP is required for colonisation of catfish ovary cells and increased apoptosis and necrosis in anterior kidney macrophages.

Apoptosis Induction of Fibroblast-Like Synoviocytes Is an Important Molecular-Mechanism for Herbal Medicine along with its Active Components in Treating Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a known chronic autoimmune disease can cause joint deformity and even loss of joint function. Fibroblast-like synoviocytes (FLS), one of the main cell types in synovial tissues of RA patients, are key effector cells in the development of RA and are considered as promising therapeutic targets for treating RA. Herbal medicines are precious resources for finding novel agents for treating various diseases including RA. It is reported that induction of apoptosis in FLS is an important mechanism for the herbal medicines to treat RA. Consequently, this paper reviewed the current available references on pro-apoptotic effects of herbal medicines on FLS and summarized the related possible signal pathways. Taken together, the main related signal pathways are concluded as death receptors mediated apoptotic pathway, mitochondrial dependent apoptotic pathway, NF-κB mediated apoptotic pathways, mitogen-activated protein kinase (MAPK) mediated apoptotic pathway, endoplasmic reticulum stress (ERS) mediated apoptotic pathway, PI3K-Akt mediated apoptotic pathway, and other reported pathways such as janus kinase/signal transducers and activators of transcription (JAK-STAT) signal pathway. Understanding the apoptosis induction pathways in FLS of these herbal medicines will not only help clear molecular mechanisms of herbal medicines for treating RA but also be beneficial for finding novel candidate therapeutic drugs from natural herbal medicines. Thus, we expect the present review will highlight the importance of herbal medicines and its components for treating RA via induction of apoptosis in FLS, and provide some directions for the future development of these mentioned herbal medicines as anti-RA drugs in clinical.

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.

Antitumor Effect of the Chalcone Analogue, (E) -1-(4-Ethoxy-3-Methoxyphenyl) -5- Methylhex-1-En-3-One on HeLa Cell Line

Chalcones represent precursor compounds for flavonoids biosynthesis in plants. Chalcones, 1,3-diaryl-2-propen-1-ones, have unique chemical structure with conjugated double bonds and delocalized π-electron system on both aromatic rings. Various studies have shown that chemical structure of chalcone is responsible for their antitumor effect. In our study, we have examined the antitumor effect of chalcone analogue (E) -1- (4-ethoxy-3-methoxyphenyl) -5-methylhex-1-en-3-one (CH) on HeLa cells. The antitumor efficiency of different CH concentrations was compared to the antitumor effects of dehydrozingerone and cisplatin. The viability of the cells was evaluated using MTT assay; type of the cell death was evaluated by Annexin V-FITC/7-AAD staining using FACS analysis; morphology changes of treated cells were visualized and compared to untreated cells using phase contrast microscopy. The result of our research showed that CH have a stronger antitumor compared to the effect both of dehydrozingerone and cisplatin. Our results indicated that chalcone analogue induced cell death via activation of apoptosis more powerfully compared to the apoptosis induced with dehydrozingerone and cisplatin.

Destined to Die: Apoptosis and Pediatric Cancers

Apoptosis (programmed cell death) is a systematic and coordinated cellular process that occurs in physiological and pathophysiological conditions. Sidestepping or resisting apoptosis is a distinct characteristic of human cancers including childhood malignancies. This review dissects the apoptosis pathways implicated in pediatric tumors. Understanding these pathways not only unraveled key molecules that may serve as potential targets for drug discovery, but also molecular nodes that integrate with other signaling networks involved in processes such as development. This review presents current knowledge of the complex regulatory system that governs apoptosis with respect to other processes in pediatric cancers, so that fresh insights may be derived regarding treatment resistance or for more effective treatment options.

Positive and negative regulators of osteoclast apoptosis

Survival and apoptosis are of major importance in the osteoclast life cycle. As osteoclasts have short lifespan, any alteration that prolongs their viability may cause enhanced osteoclast activity. Hence, the regulation of OC apoptosis has been recognized as a critical factor in bone remodeling. An imbalance in bone remodeling due to increased osteoclast activity leads to most adult bone diseases such as osteoporosis, rheumatoid arthritis and multiple myeloma. Therefore, manipulating osteoclast death would be a viable therapeutic approach in ameliorating bone diseases, with accelerated resorption. Over the last few decades we have witnessed the unraveling of many of the intracellular mechanisms responsible for osteoclast apoptosis. Thus, an understanding of the underlying mechanisms by which osteoclasts undergo programmed cell death and the regulators that modulate that activity will undoubtedly provide an insight into the development of pharmacological agents to treat such pathological bone diseases.

Effects of Live Attenuated Vaccine and Wild Type Strains of Edwardsiella ictaluri on Phagocytosis, Bacterial Killing, and Survival of Catfish B Cells

Edwardsiella ictaluri, a Gram-negative facultative intracellular pathogen, is the causative agent of enteric septicemia of catfish (ESC). The innate functions of B cells have been demonstrated in several teleost fish, including zebrafish, rainbow trout, and channel catfish. Recently, our group has developed several protective E. ictaluri live attenuated vaccines (LAVs). However, the innate role of catfish B cells to phagocytose and destroy E. ictaluri wild-type (WT) and live attenuated vaccine (LAV) strains has not been evaluated. In this study, we assessed the efficacy of E. ictaluri WT and two LAVs on phagocytosis, microbial killing, and survival of catfish anterior kidney (AK) B cells. Initially, we documented active uptake of E. ictaluri WT and two LAVs in B cells by flow cytometry and light microscopy. Then, we observed the E. ictaluri strains-induced phagosome and/or phagolysosome formation in the cytoplasm of catfish magnetically sorted IgM+ B cells. Furthermore, we demonstrated that AK B cells were able to destroy the internalized E. ictaluri WT and LAV strains efficiently. Finally, we documented early and late apoptotic/necrotic manifestations induced by E. ictaluri in catfish AK B cells. In conclusion, our results suggest that both LAVs and WT strain initiate similar innate immune responses such as active phagocytic uptake, induced bactericidal activity as well as promote early and late apoptotic changes in catfish B cells. Our data suggest that phagocytic and microbicidal B cells may serve as professional APCs in initiation of protective adaptive immune responses against ESC in channel catfish.

Resveratrol Protects against Restraint Stress Effects on Stomach and Spleen in Adult Male Mice

The objectives were to investigate whether restraint stress (which is known as a mixture of psychologic and physical stress) exerts negative effects on the stomach and spleen, and whether the phenolic compound resveratrol (RES) exerts any protective roles. Fifty adult male mice were divided into five groups, with 10 mice per group as follows: control (C), restraint stress (RS), RS with vehicle (RS + V), RS with 2 mg/kg of resveratrol (RS + 2 mg RES), and RS with 20 mg/kg of resveratrol (RS + 20 mg RES). Mice were restrained in conical centrifuge tubes for 4 h daily to establish the RS model. RS + 2 mg RES, RS + 20 mg RES, and RS + V groups were given an oral dose of resveratrol or vehicle for 15 consecutive days, while the control group was not exposed to restraint stress. Herein, we showed that restraint stress decreased body weight and food and water consumption in stressed groups RS and RS + V compared to controls, while the groups treated with resveratrol showed improvements. Moreover, restraint stress caused acute damage to the morphology of gastric cells and reduced the quantitative distribution of parietal cells along with their decreased size and diameter, pointing to gastritis or ulcer. Furthermore, the antibody against the apoptosis-inducing factor (AIF) was highly attached in the RS groups. Splenic size, weight, and length were also greatly augmented in the stressed groups compared to the controls, while these phenomena were not observed in the RS + 2 mg RES group. Our findings proved significant ameliorating effects of resveratrol against restraint stress in adult male mice.

Identification of carbon nanotube particles in liver tissue and its effects on apoptosis of birds exposed to air pollution

Aim

This study aimed to distinguish carbon nanotube (CNT) particles and their pathological effects on the liver of birds in areas with carbon emissions.

Materials and Methods

Twenty-one domestic ducks were collected from pure farmers and exposed to different sources of air pollution. Histological stains were used to detect the accumulation of carbon particles. In addition, acridine orange/ethidium bromide staining was used to detect apoptosis, and scanning electron microscope (SEM) technique was used to determine the morphological design of carbon particles.

Results

Light microscope results showed that the liver sections contain multiwalled CNTs (MWCNTs) which appear as black spots in the hepatic parenchyma. The histopathological changes of parenchyma include sinusoidal dilatation, infiltration, and congestion with frequently high number of macrophages. In general, early destruction of hepatic parenchyma was observed. Moreover, SEM results showed two morphological types of CNTs: The ball-shaped nanoparticles scattered as ultrafine carbon black and fiber form of carbon particles were recognized as MWCNTs in the hepatic tissue. Fluorescence microscopy results showed the early and progressive stages of apoptosis in the hepatic cells of birds in polluted areas, which can be related to the degree and exposure period to pollutants.

Conclusion

The study indicates that liver morbidity of birds living in the farms affected by the pollution of brick factories is higher than the birds living in farms affected by the pollution of oil fields.

Implications of Necroptosis for Cardiovascular Diseases

Necroptosis is a non-apoptotic programmed cell death pathway, which causes necrosis-like morphologic changes and triggers inflammation in the surrounding tissues. Accumulating evidence has demonstrated that necroptosis is involved in a number of pathological processes that lead to cardiovascular diseases. However, the exact molecular pathways linking them remain unknown. Herein, this review summarizes the necroptosis-related pathways involved in the development of various cardiovascular diseases, including atherosclerosis, cardiac ischemia-reperfusion injury, cardiac hypertrophy, dilated cardiomyopathy and myocardial infarction, and may shed light on the diagnosis and treatment of these diseases.

Real-Time Live-Cell Imaging Technology Enables High-Throughput Screening to Verify in Vitro Biocompatibility of 3D Printed Materials

With growing advances in three-dimensional (3D) printing technology, the availability and diversity of printing materials has rapidly increased over the last years. 3D printing has quickly become a useful tool for biomedical and various laboratory applications, offering a tremendous potential for efficiently fabricating complex devices in a short period of time. However, there still remains a lack of information regarding the impact of printing materials and post-processing techniques on cell behavior. This study introduces real-time live-cell imaging technology as a fast, user-friendly, and high-throughput screening strategy to verify the in vitro biocompatibility of 3D printed materials. Polyacrylate-based photopolymer material was printed using high-resolution 3D printing techniques, post-processed using three different procedures, and then analyzed with respect to its effects on cell viability, apoptosis, and necrosis of adipogenic mesenchymal stem cells (MSCs). When using ethanol for the post-processing procedure and disinfection, no significant effects on MSCs could be detected. For the analyses a novel image-based live-cell analysis system was compared against a biochemical-based standard plate reader assay and traditional flow cytometry. This comparison illustrates the superiority of using image-based detection of in vitro biocompatibility with respect to analysis time, usability, and scientific outcome.

Cellular senescence and radiation-induced pulmonary fibrosis

Radiation-induced pulmonary fibrosis (RIPF) is a serious treatment complication that affects about 9%-30% cancer patients receiving radiotherapy for thoracic tumors. RIPF is characterized by progressive and irreversible destruction of lung tissues and deterioration of lung function, which can compromise quality of life and eventually lead to respiratory failure and death. Unfortunately, the mechanisms by which radiation causes RIPF have not been well established nor has an effective treatment for RIPF been developed. Recently, an increasing body of evidence suggests that induction of senescence by radiation may play an important role in RIPF and clearance of senescent cells (SnCs) with a senolytic agent, small molecule that can selectively kill SnCs, has the potential to be developed as a novel therapeutic strategy for RIPF. This review discusses some of these new findings to promote further study on the role of cellular senescence in RIPF and the development of senolytic therapeutics for RIPF.

Loganin Attenuates Osteoarthritis in Rats by Inhibiting IL-1β-Induced Catabolism and Apoptosis in Chondrocytes Via Regulation of Phosphatidylinositol 3-Kinases (PI3K)/Akt

Background

Chondrocyte apoptosis and catabolism are 2 major factors that contribute to the progression of osteoarthritis (OA). Loganin, an iridoid glycoside present in several herbs, including Flos lonicerae, Cornus mas L, and Strychnos nux vomica, is a valuable medication with anti-inflammatory and anti-apoptotic effects. Our study examines these effects and explores the potential benefits of loganin in the OA treatment.

Material/Methods

To clarify the roles of loganin in OA and its specific signaling pathway, chondrocytes were administrated with IL-1β and supplemented with or without LY294002 (a classic PI3K/Akt inhibitor). The apoptotic level, catabolic factors (MMP-3 and MMP-13 and ADAMTS-4 and ADAMTS-5), extracellular matrix (ECM) degradation, and activation of the PI3K/Akt pathway were evaluated using western blotting, PCR, and an immunofluorescent assay. The degenerative condition of the cartilage was evaluated using the Safranin O assay in vivo. The expression of cleaved-caspase-3 (C-caspase-3) was measured using immunochemistry.

Results

The data suggested that loganin suppressed the apoptotic level, reduced the release of catabolic enzymes, and decreased the ECM degradation of IL-1β-induced chondrocytes. However, suppressing PI3K/Akt signaling using LY294002 alleviated the therapeutic effects of loganin in chondrocytes. Our in vivo experiment showed that loganin partially attenuated cartilage degradation while inhibiting the apoptotic level.

Conclusions

This work revealed that loganin treatment attenuated IL-1β-treated apoptosis and ECM catabolism in rat chondrocytes via regulation of the PI3K/Akt signaling, revealing that loganin is a potentially useful treatment for OA.

The cGAS-cGAMP-STING Pathway: A Molecular Link Between Immunity and Metabolism

It has been appreciated for many years that there is a strong association between metabolism and immunity in advanced metazoan organisms. Distinct immune signatures and signaling pathways have been found not only in immune but also in metabolic cells. The newly discovered DNA-sensing cGAS-cGAMP-STING pathway mediates type I interferon inflammatory responses in immune cells to defend against viral and bacterial infections. Recent studies show that this pathway is also activated by host DNA aberrantly localized in the cytosol, contributing to increased sterile inflammation, insulin resistance, and the development of nonalcoholic fatty liver disease (NAFLD). Potential interactions of the cGAS-cGAMP-STING pathway with mTORC1 signaling, autophagy, and apoptosis have been reported, suggesting an important role of the cGAS-cGAMP-STING pathway in the networking and coordination of these important biological processes. However, the regulation, mechanism of action, and tissue-specific role of the cGAS-cGAMP-STING signaling pathway in metabolic disorders remain largely elusive. It is also unclear whether targeting this signaling pathway is effective for the prevention and treatment of obesity-induced metabolic diseases. Answers to these questions would provide new insights for developing effective therapeutic interventions for metabolic diseases such as insulin resistance, NAFLD, and type 2 diabetes.

The New Compound of (2R, 4S)-N-(2, 5-difluorophenyl)-4-Hydroxy-1-(2, 2, 2-Trifluoroacetyl) Pyrrolidine-2-Carboxamide to Mediate the Expression of Some Apoptosis Genes by the HepG2 Cell Line

Objectives: Hepatocellular carcinoma is one of the most frequent cancers worldwide, for the treatment of which various therapy protocols and drugs have been introduced; however, none of them has suppressed cancer tissues completely. New research programs have been developed on cancer and the accompanied effects of novel synthesized compounds on cancer cell lines. Our latest reports on the molecular basis of cancer revealed a pattern of changes in gene expression triggered in the cancer pathway. Methods: HepG2 cell lines were cultured under similar conditions in both test and control groups. The IC50 concentration of the (2R, 4S)-N-(2, 5-difluorophenyl)-4-hydroxy-1-(2, 2, 2-trifluoroacetyl) pyrrolidine-2-carboxamide compound was used in the treatment group. After 48 hours from the culture, the expressional profiles of apoptosis pathway genes (84 genes) were studied using the PCR array method. Results: The findings demonstrated that the expression of some apoptosis-related genes pertaining to TNF, BCL2, IAP, and caspase families was regulated by (2R, 4S)-N-(2, 5-difluorophenyl)-4-Hydroxy-1-(2, 2, 2-Trifluoroacetyl) Pyrrolidine-2-Carboxamide. In the same vein, an alteration was observed in the expression of both pro-apoptotic and anti-apoptotic genes associated with the extrinsic and intrinsic apoptosis signaling pathways. Conclusions: According to the data obtained, the pyrrolidine-2-carboxamide compound was demonstrated to be able to regulate the apoptotic activities of HepG2 cells by affecting both pro-apoptotic and anti-apoptotic relevant genes.

Graviola attenuates DMBA-induced breast cancer possibly through augmenting apoptosis and antioxidant pathway and downregulating estrogen receptors

Breast cancer is a global public health problem where it is the second most prevalent cancer. Historical cancer treatment with graviola has been reported. This study aimed to investigate the protective effects of graviola on 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat breast cancer. Fifty female Wistar rats were allocated into four groups: control group (gastro-gavaged by sesame oil), DMBA-treated group (gastro-gavaged a single dose of DMBA [50 mg/kg body mass, diluted in 1 ml sesame oil]) at the age 57 days, DMBA+G37-treated group (gastro-gavaged a single dose of DMBA [50 mg/kg body mass, diluted in 1 ml sesame oil]) at the age of 57 days plus graviola (200 mg/kg body mass) two times weekly (p.o.) at the age of 37 days till the end of the experiment, and DMBA+G57-treated group (received a single dose of DMBA [50 mg/kg body mass, diluted in 1 ml sesame oil]) plus graviola (200 mg/kg body mass) two times weekly at the age of 57 days until the end of the experiment. After the 30-week experimental period, blood samples were collected. Then, animals were sacrificed to determine the apoptotic indices, antioxidant status, and mammary gland tumor marker (CA 15-3). The DMBA upregulated the expression of one of the main anti-apoptotic genes: B-cell lymphoma protein 2 (BCL2) and estrogen receptor alpha (ER-α) gene. Moreover, it significantly increased breast lipid peroxidation and serum CA 15-3 but decreased breast antioxidant enzymatic activities (glutathione peroxidase, glutathione S-transferase, catalase, and superoxide dismutase). Nevertheless, administration of DMBA and graviola especially DMBA+G37 induced apoptosis through at least 1.5-fold in gene expression levels of pro-apoptotic genes: BCL2-associated X protein (BAX), tumor suppressor gene (P53), and cysteinyl-aspartic acid-protease-3 (caspase-3). A critical role of P53 in the regulation of the BCL2 and BAX has been reported. These proteins can determine if the cell undergoes apoptosis or cancels the process. Once the BAX gene activates caspase-3, there is no irreversible way toward cell death. Also, graviola ameliorated the DMBA effects on antioxidant enzymatic activities and tumor marker CA 15-3. This study concludes that graviola ameliorated DMBA-induced breast cancer potentially through upregulating apoptotic genes, downregulating the ER-α gene, increasing antioxidants, and decreasing lipid peroxidation levels.

Leaf anatomy and ultrastructure in senescing ancient tree, Platycladus orientalis L. (Cupressaceae)

Platycladus orientalis L. (Cupressaceae) has a lifespan of thousands of years. Ancient trees have very high scientific, economic and cultural values. The senescence of ancient trees is a new research area but is poorly understood. Leaves are the primary and the most sensitive organ of a tree. To understand leaf structural response to tree senescence in ancient trees, experiments investigating the morphology, anatomy and ultrastructure were conducted with one-year leaves of ancient P. orientalis (ancient tree >2,000 years) at three different tree senescent levels (healthy, sub-healthy and senescent) at the world's largest planted pure forest in the Mausoleum of Yellow Emperor, Shaanxi Province, China. Observations showed that leaf structure significantly changed with the senescence of trees. The chloroplast, mitochondria, vacuole and cell wall of mesophyll cells were the most significant markers of cellular ultrastructure during tree senescence. Leaf ultrastructure clearly reflected the senescence degree of ancient trees, confirming the visual evaluation from above-ground parts of trees. Understanding the relationships between leaf structure and tree senescence can support decision makers in planning the protection of ancient trees more promptly and effectively by adopting the timely rejuvenation techniques before the whole tree irreversibly recesses.

Loss of MIEF1/MiD51 confers susceptibility to BAX-mediated cell death and PINK1-PRKN-dependent mitophagy

Mitochondrial dynamics is highly implicated in a plethora of cellular processes including apoptosis and mitophagy. However, little is known about the scope and precise functions of mitochondrial dynamics proteins for mitochondrial quality control and cellular homeostasis. Whether mitochondrial dynamics proteins serve in cellular processes reliant on mitochondrial fission-fusion is still not fully explored. MIEF1/MiD51 (mitochondrial elongation factor 1) is known to promote mitochondrial fission via the recruitment of GTPase protein DNM1L/DRP1 (dynamin 1 like), but the fundamental understandings of MIEF1 for mitochondrial-dependent cellular processes are largely elusive. Here, we report novel roles of MIEF1 in responding to apoptotic stimuli and mitochondrial damage. Given our result that staurosporine (STS) treatment induced the degradation of MIEF1 via the ubiquitin-proteasome system (UPS), we are motivated to explore the role of MIEF1 in apoptosis. MIEF1 loss triggered the imbalance of BCL2 family members on the mitochondria, consequently initiating the translocation of BAX onto the mitochondria, catalyzing the decrease of mitochondrial membrane potential and promoting the release of DIABLO/SMAC (diablo IAP-binding mitochondrial protein) and CYCS (cytochrome c, somatic). We further demonstrate that MIEF1 deficiency impaired mitochondrial respiration and induced mitochondrial oxidative stress, sensitizing cells to PINK1-PRKN-mediated mitophagy. The recruitment of PRKN to depolarized mitochondria modulated the UPS-dependent degradation of MFN2 (mitofusin 2) and FIS1 (fission, mitochondrial 1) specifically, to further promote mitophagy. Our findings uncover a bridging role of MIEF1 integrating cell death and mitophagy, unlikely dependent on mitochondrial dynamics, implying new insights to mechanisms determining cellular fate.Abbreviations: ActD: actinomycin D; BAX: BCL2 associated X, apoptosis regulator; BAK1: BCL2 antagonist/killer 1; BCL2L1: BCL2 like 1; BMH: 1,6-bismaleimidohexane; CCCP: carbonyl cyanide 3-chlorophenylhydrazone; CHX: cycloheximide; CQ: chloroquine; CYCS: cytochrome c, somatic; DIABLO: diablo IAP-binding mitochondrial protein; DKO: double knockout; DNM1L/DRP1: dynamin 1 like; FIS1: fission, mitochondrial 1; GFP: green fluorescent protein; IP: immunoprecipitation; MFN1: mitofusin 1; MFN2: mitofusin 2; MG132: carbobenzoxy-Leu-Leu-leucinal; MIEF1/MiD51: mitochondrial elongation factor 1; MIEF2/MiD49: mitochondrial elongation factor 2; MOMP: mitochondrial outer membrane permeabilization; MTR: MitoTracker Red; OA: oligomycin plus antimycin A; OCR: oxygen consumption rate; OMM: outer mitochondrial membrane; PARP: poly(ADP-ribose) polymerase; PI: propidium iodide; PINK1: PTEN induced kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; ROS: reactive oxygen species; SD: standard deviation; STS: staurosporine; TNF: tumor necrosis factor; UPS: ubiquitin-proteasome system; VDAC1: voltage dependent anion channel 1.

Ursolic Acid Induces Apoptotic Cell Death Through AIF and Endo G Release Through a Mitochondria-dependent Pathway in NCI-H292 Human Lung Cancer Cells In Vitro

BACKGROUND/AIM

Ursolic acid (UA), a triterpene compound present in natural plants, has been shown to induce cytotoxic effects on many human cancer cells through induction of cell-cycle arrest and apoptosis. This study investigated the effects of UA on human lung cancer NCI-H292 cells in vitro.

MATERIALS AND METHODS

Flow cytometric assay was used to measure the percentage of cell viability, apoptotic cell death by double staining of annexin V and propidium iodide (PI), production of reactive oxygen species (ROS) and Ca2+, and mitochondriaI membrane potential (Ψm). UA-induced chromatin condensation and DNA fragmentation were examined by 4',6-diamidino-2-phenylindole staining and DNA gel electrophoresis, respectively. Western blotting was used to examine the changes of apoptosis-associated protein expression in NCI-H292 cells.

RESULTS

UA reduced cell viability and induced apoptotic cell death. UA increased Ca2+ production, reduced Ψm, but did not affect ROS production in NCI-H292 cells. UA increased apoptosis-inducing factor (AIF) and endonuclease G in NCI-H292 cells.

CONCLUSION

Based on these observations, we suggest UA induces apoptotic cell death via AIF and Endo G release through a mitochondria-dependent pathway in NCI-H292 cells.

Impaired HPA axis function in diabetes involves adrenal apoptosis and phagocytosis

PURPOSE

The aim of the present study was to analyze the involvement of oxidative stress and inflammation in the modulation of glucocorticoid production in the adrenal cortex of diabetic rats.

METHODS

Male Wistar rats were treated with or without streptozotocin (STZ, an insulinopenic model of diabetes) and either α-lipoic (90 mg/kg ip.), α-tocopherol (200 mg/kg po.) or with STZ and supplemented with insulin (STZ + INS: 2.5U/day) for 4 weeks. Oxidative/nitrosative stress parameters and antioxidant enzymes were determined in adrenocortical tissues. Apoptosis and macrophage activation were evaluated by immunohistochemistry (TUNEL and ED1⁺). Basal and ACTH-stimulated corticosterone production were assessed by RIA and plasma ACTH levels were determined by an immunometric assay.

RESULTS

Diabetic rats showed a diminished response to exogenous ACTH stimulation along with higher basal corticosterone and lower plasma ACTH levels. In the adrenal cortex we determined an increase in the levels of lipoperoxides, S-nitrosothiols, nitric oxide synthase activity and nitro-tyrosine modified proteins while catalase activity and heme oxygenase-1 expression levels were also elevated. Antioxidant treatments were effective in the prevention of these effects, and in the increase in the number of apoptotic and phagocytic (ED1⁺) cells detected in diabetic rats. No changes were observed in the STZ + INS group.

CONCLUSIONS

Generation of oxidative/nitrosative stress in the adrenal cortex of diabetic rats leads to the induction of apoptosis and the activation of adrenocortical macrophages and is associated with an elevated basal corticosteronemia and the loss of the functional capacity of the gland.

Bax to the future - A novel, high-yielding approach for purification and expression of full-length Bax protein for structural studies

Mitochondria-mediated apoptosis (programmed cell death) involves a sophisticated signaling and regulatory network that is regulated by the Bcl-2 protein family. Members of this family have either pro- or anti-apoptotic functions. An important pro-apoptotic member of this family is the cytosolic Bax. This protein is crucial for the onset of apoptosis by perforating the mitochondrial outer membrane (MOM). This process can be seen as point of no return, since disintegration of the MOM leads to the release of apotogenic factors such as cytochrome c into the cytosol triggering the activation of caspases and subsequent apoptotic steps. Bax is able to interact with the MOM with both its termini, making it inherently difficult to express in E. coli. In this study, we present a novel approach to express and purify full-length Bax with significantly increased yields, when compared to the commonly applied strategy. Using a double fusion approach with an N-terminal GST-tag and a C-terminal Intein-CBD-tag, we were able to render both Bax termini inactive and prevent disruptive interactions from occurring during gene expression. By deploying an Intein-CBD-tag at the C-terminus we were further able to avoid the introduction of any artificial residues, hence ensuring the native like activity of the membrane-penetrating C-terminus of Bax. Further, by engineering a His₆-tag to the C-terminus of the CBD-tag we greatly improved the robustness of the purification procedure. We report yields for pure, full-length Bax protein that are increased by an order of magnitude, when compared to commonly used Bax expression protocols.

New Drugs from the Sea: Pro-Apoptotic Activity of Sponges and Algae Derived Compounds

Natural compounds derived from marine organisms exhibit a wide variety of biological activities. Over the last decades, a great interest has been focused on the anti-tumour role of sponges and algae that constitute the major source of these bioactive metabolites. A substantial number of chemically different structures from different species have demonstrated inhibition of tumour growth and progression by inducing apoptosis in several types of human cancer. The molecular mechanisms by which marine natural products activate apoptosis mainly include (1) a dysregulation of the mitochondrial pathway; (2) the activation of caspases; and/or (3) increase of death signals through transmembrane death receptors. This great variety of mechanisms of action may help to overcome the multitude of resistances exhibited by different tumour specimens. Therefore, products from marine organisms and their synthetic derivates might represent promising sources for new anticancer drugs, both as single agents or as co-adjuvants with other chemotherapeutics. This review will focus on some selected bioactive molecules from sponges and algae with pro-apoptotic potential in tumour cells.

Free Radical Scavenging Properties and Induction of Apoptotic Effects of Fa Fraction Obtained after Proteolysis of Bioactive Peptides from Microalgae Synechococcus sp. VDW

This study aims to determine the antioxidant activity of bioactive peptides derived from Synechococcus sp. VDW cells cultured for 21 days. Synechococcus sp. VDW protein hydrolysates were prepared with trypsin and purified by ultrafiltration with molecular mass cut-off membranes of 10, 5 and 3 kDa. The M<3 kDa (F_A) fraction had the highest 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2’-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, with IC₅₀ values of (11.5±0.3) and (13.6±0.2) µg/mL, respectively. The F_A fraction was separated by reversed phase HPLC to yield four subfractions (F_1–4). The F₄ subfraction showed the highest maximum ABTS radical scavenging activity (3.55±0.61) % and it was selected for further analysis by electrospray ionisation quadrupole time-of-flight mass spectrometry (ESI-Q-TOF-MS/MS) based on de novo peptide sequencing. Five antioxidant peptides were identified, of which AILESYSAGKTK had the highest ABTS radical scavenging activity. Furthermore, the F_A fraction showed high cytotoxic activities against human cancer-derived cell lines, especially the colon cancer cell line (SW620) with an IC₅₀ value of (106.6±21.5) µg/mL, but not the untransformed Wi38 cell line. The F_A fraction activated the apoptotic pathway in SW620 cells after treatment for 24, 48 and 72 h, with the highest activities of caspases-3, -8 and -9 being observed after treatment for 72 h. These findings suggested that microalgae Synechococcus sp. VDW may be used to develop natural anticancer drugs.

An imazamox-based herbicide causes apoptotic changes in rat liver and pancreas

We studied the acute toxicity of an imazamox-based herbicide at 12, 24 and 36 mg/kg body (bw) weight imazamox equivalent dose on the liver and pancreatic tissue in Sprague Dawley rats. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, glucose, calcium as well as creatinine, were determined in blood samples, which were collected after 24, 48 and 72 h exposure. Caspase 3 and anti-insulin expression and immunopositivity were evaluated using in situ hybridization and immunohistochemistry, respectively. The imazamox-based herbicide evaluated in this study induced toxic effects even from the lowest dose tested (12 mg/kg bw). The two highest doses caused a statistically significant cytotoxicity on the Langerhans islet cells. Necrotic and degenerative changes were detected in hepatocytes at the two highest doses. Imazamox is considered to be poorly toxic to the liver. Nevertheless, the imazamox-based herbicide formulation tested here reduced the size of the β-islet cells, induced an elevation in serum glucose and calcium. Our data shows that commercial formulations of imazamox containing various co-formulants can have hepatic and pancreatic toxic effects.

Long-term crowding stress causes compromised nonspecific immunity and increases apoptosis of spleen in grass carp (Ctenopharyngodon idella)

Crowding stress is one of the most common environmental stressors in intensive aquaculture. To investigate the influences of long-term crowding stress on nonspecific immune responses and apoptosis in fish, grass carp (Ctenopharyngodon idella) were cultured at low (0.9 kg m^-2), medium (2.97 kg m^-2) and high (5.9 kg m^-2) stocking densities for 10 weeks in the present study. The results showed that elevation of stocking densities caused splenic tissue damages and inflammatory responses, which are characterized with the formation of melano-macrophage centers and the increase of granulocytes as well as significant upregulation of inflammatory cytokine genes (il1β and tnfα). The remarkable decline in the activities of serum lysozyme, acid phosphatase and alkaline phosphatase under high stocking density further confirmed that increased stocking density affected fish nonspecific immune response negatively. Moreover, the transcriptional levels of splenic apoptotic-related genes caspase-8, fasl and caspase-3 increased significantly while the mRNA levels of bax, bcl2, apaf1 and caspase-9 remained unchanged. This result showed that increased stocking density caused splenic cell apoptosis, which were closely associated with the FasL signaling pathway. Our findings revealed that crowding stress could influence fish nonspecific immune response negatively and increase inappropriate apoptosis of the spleen, which would make fish more susceptible to pathogens and ultimately impair fish survival. The breeding density utilized in this study also provides some reference values in intensive aquaculture systems from the perspective of fish health and welfare.

Role of microRNAs in the main molecular pathways of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignant neoplasia. HCC is characterized by a poor prognosis. The need to find new molecular markers for its diagnosis and prognosis has led to a progressive increase in the number of scientific studies on this topic. MicroRNAs (miRNAs) are small non-coding RNA that play a role in almost all main cellular pathways. miRNAs are involved in the regulation of expression of the major tumor-related genes in carcinogenesis, acting as oncogenes or tumor suppressor genes. The aim of this review was to identify papers published in 2017 investigating the role of miRNAs in HCC tumorigenesis. miRNAs were classified according to their role in the main molecular pathways involved in HCC tumorigenesis: (1) mTOR; (2) Wnt; (3) JAK/STAT; (4) apoptosis; and (5) MAPK. The role of miRNAs in prognosis/response prediction was taken into consideration. Bearing in mind that the analysis of miRNAs in serum and other body fluids would be crucial for clinical management, the role of circulating miRNAs in HCC patients was also investigated. The most represented miRNA-regulated pathway in HCC is mTOR, but apoptosis, Wnt, JAK/STAT or MAPK pathways are also influenced by miRNA expression levels. These miRNAs could thus be used in clinical practice as diagnostic, prognostic or therapeutic targets for HCC treatment.

A potential molecular model for studying apoptosis enhanced by the interaction of BCL-G with JAB1 in swine

BCL-G, an apoptotic factor in Bcl-2 family, is involved in several kinds of diseases by interacting with several proteins. Although many studies on mouse and human BCL-G have been reported, porcine BCL-G (pBCL-G) has been little investigated. In this study, our results showed that pBCL-G was universally expressed in porcine tissues. The BH2 domain affected the subcellular distribution of pBCL-G protein. pBCL-G could interact with porcine JAB1 (pJAB1), by which its subcellular distribution was affected. pBCL-G promoted staurosporine-induced apoptosis that was significantly enhanced by interaction of pBCL-G with pJAB1. The apoptosis at least partially depended on the activated caspase-8, -9 and -3. Owing to the close phylogenetic distance between pigs and humans and their many physiological similarities, our findings may provide a potential molecular model to study human BCL-G and also may have implications in the treatment of diseases relevant with BCL-G.

Upregulation of neuronal astrocyte elevated gene-1 protects nigral dopaminergic neurons in vivo

The role of astrocyte elevated gene-1 (AEG-1) in nigral dopaminergic (DA) neurons has not been studied. Here we report that the expression of AEG-1 was significantly lower in DA neurons in the postmortem substantia nigra of patients with Parkinson’s disease (PD) compared to age-matched controls. Similarly, decreased AEG-1 levels were found in the 6-hydroxydopamine (6-OHDA) mouse model of PD. An adeno-associated virus-induced increase in the expression of AEG-1 attenuated the 6-OHDA-triggered apoptotic death of nigral DA neurons. Moreover, the neuroprotection conferred by the AEG-1 upregulation significantly intensified the neurorestorative effects of the constitutively active ras homolog enriched in the brain [Rheb(S16H)]. Collectively, these results demonstrated that the sustained level of AEG-1 as an important anti-apoptotic factor in nigral DA neurons might potentiate the therapeutic effects of treatments, such as Rheb(S16H) administration, on the degeneration of the DA pathway that characterizes PD.