Labelling DNA strand breaks with BrdUTP. Detection of apoptosis and cell proliferation

Protective effects of curcumin on corneal endothelial cell PANoptosis and monocyte adhesion induced by tumor necrosis factor-alpha and interferon-gamma in rats

Decrease of human corneal endothelial cell (CEC) density leads to corneal edema, progressive corneal opacity, and reduced visual acuity. A reduction in CEC density may be related to elevated levels of inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interferon (INF)-γ. PANoptosis, characterized by the activation of apoptosis, necroptosis, and pyroptosis, could be a factor in the loss of CECs driven by TNF-α and INF-γ. Cytokines also stimulate monocytes adhesion to endothelium. It has been shown in previous research that curcumin plays protective roles against numerous corneal inflammatory diseases. However, it is not determined whether curcumin acts as an anti-PANoptotic agent or if it mitigates monocyte adhesion to CECs. Therefore, this research aimed to explor the potential therapeutic effects of curcumin and its underlying mechanisms in the loss of CECs. CEC injury models were established, and curcumin was injected subconjunctivally. Clinical evaluation of the corneas was conducted using a scoring system and anterior segment photography. Corneal observation was performed with hematoxylin and eosin staining and immunostaining of zona occludens-1(ZO-1). Apoptotic cells within the corneal endothelium were observed using TUNEL staining. The detection of primary proteins expression was accomplished through Western blot analysis. Interleukin (IL)-1β and macrophage chemotactic protein 1 (MCP-1) levels were determined via ELISA, while the expression of cleaved caspase-3, gasdermin-D (GSDMD), phosphor-mixed lineage kinase domain-like protein (p-MLKL) and intercellular cell adhesion molecule-1 were confirmed by immunofluorescence. Myeloperoxidase (MPO) activity was measured in aqueous humors. Curcumin treatment attenuated the loss of CECs and corneal edema caused by TNF-α and IFN-γ. Besides, it decreased the count of TUNEL-positive cells, and inhibited the upregulation of cleaved caspase-3, cleaved caspase-6, cleaved caspase-7, and cleaved poly (ADP-ribose) polymerase. Moreover, both the expression and phosphorylation of MLKL and receptor-interacting protein 3 were decreased in curcumin-treated rats. Furthermore, curcumin also lowered the expression of cleaved caspase-1, diminished the levels of IL1β and MCP-1, and inhibited the activity of MPO. Besides, the expression of intercellular cell adhesion molecule-1, vascular cell adhesion molecule-1, as well as the number of CD11b-positive cells adhered to the CECs decreased for the administration of curcumin.

High-throughput assays to assess variant effects on disease

Interpreting the wealth of rare genetic variants discovered in population-scale sequencing efforts and deciphering their associations with human health and disease present a critical challenge due to the lack of sufficient clinical case reports. One promising avenue to overcome this problem is deep mutational scanning (DMS), a method of introducing and evaluating large-scale genetic variants in model cell lines. DMS allows unbiased investigation of variants, including those that are not found in clinical reports, thus improving rare disease diagnostics. Currently, the main obstacle limiting the full potential of DMS is the availability of functional assays that are specific to disease mechanisms. Thus, we explore high-throughput functional methodologies suitable to examine broad disease mechanisms. We specifically focus on methods that do not require robotics or automation but instead use well-designed molecular tools to transform biological mechanisms into easily detectable signals, such as cell survival rate, fluorescence or drug resistance. Here, we aim to bridge the gap between disease-relevant assays and their integration into the DMS framework.

Genotyping of rams based on melatonin receptor 1A gene polymorphisms: a tool in sire selection?

Context Several polymorphisms in the melatonin receptor 1A gene (MTNR1A ) have been related to reproductive performance in ovine. Aims To investigate the effect of the Rsa I and Mnl I polymorphisms on ram seminal quality. Methods Eighteen Rasa Aragonesa rams were genotyped for the Rsa I (C/C, C/T, T/T) and Mnl I (G/G, G/A, A/A) allelic variants of the MTNR1A gene. Individual ejaculates were analysed once a month throughout the whole year. Sperm motility, morphology, membrane integrity, levels of reactive oxygen species (ROS), phosphatidylserine (PS) inversion, DNA fragmentation and capacitation status were assessed. The effect of the season and polymorphisms on seminal quality was evaluated by mixed ANOVA. Key results Both polymorphisms had an effect on membrane integrity and viable spermatozoa with low levels of ROS and without PS translocation, and Rsa I also on motile and DNA-intact spermatozoa. An interaction between both polymorphisms was found, pointing to a negative effect on seminal quality of carrying the T or A allele in homozygosity. Differences were higher in the reproductive than in the non-reproductive season. Conclusions Mutations substituting C by T and G by A at Rsa I and Mnl I polymorphic sites, respectively, in the MTNR1A gene in rams could decrease the seminal quality. Implications Genotyping of rams based on melatonin receptor 1A could be a powerful tool in sire selection.

Molecular mechanisms in regulation of autophagy and apoptosis in view of epigenetic regulation of genes and involvement of liquid-liquid phase separation

Cellular physiology is critically regulated by multiple signaling nexuses, among which cell death mechanisms play crucial roles in controlling the homeostatic landscape at the tissue level within an organism. Apoptosis, also known as programmed cell death, can be induced by external and internal stimuli directing the cells to commit suicide in unfavourable conditions. In contrast, stress conditions like nutrient deprivation, infection and hypoxia trigger autophagy, which is lysosome-mediated processing of damaged cellular organelle for recycling of the degraded products, including amino acids. Apparently, apoptosis and autophagy both are catabolic and tumor-suppressive pathways; apoptosis is essential during development and cancer cell death, while autophagy promotes cell survival under stress. Moreover, autophagy plays dual role during cancer development and progression by facilitating the survival of cancer cells under stressed conditions and inducing death in extreme adversity. Despite having two different molecular mechanisms, both apoptosis and autophagy are interconnected by several crosslinking intermediates. Epigenetic modifications, such as DNA methylation, post-translational modification of histone tails, and miRNA play a pivotal role in regulating genes involved in both autophagy and apoptosis. Both autophagic and apoptotic genes can undergo various epigenetic modifications and promote or inhibit these processes under normal and cancerous conditions. Epigenetic modifiers are uniquely important in controlling the signaling pathways regulating autophagy and apoptosis. Therefore, these epigenetic modifiers of both autophagic and apoptotic genes can act as novel therapeutic targets against cancers. Additionally, liquid-liquid phase separation (LLPS) also modulates the aggregation of misfolded proteins and provokes autophagy in the cytosolic environment. This review deals with the molecular mechanisms of both autophagy and apoptosis including crosstalk between them; emphasizing epigenetic regulation, involvement of LLPS therein, and possible therapeutic approaches against cancers.

Basic Methods of Cell Cycle Analysis

Cellular growth and the preparation of cells for division between two successive cell divisions is called the cell cycle. The cell cycle is divided into several phases; the length of these particular cell cycle phases is an important characteristic of cell life. The progression of cells through these phases is a highly orchestrated process governed by endogenous and exogenous factors. For the elucidation of the role of these factors, including pathological aspects, various methods have been developed. Among these methods, those focused on the analysis of the duration of distinct cell cycle phases play important role. The main aim of this review is to guide the readers through the basic methods of the determination of cell cycle phases and estimation of their length, with a focus on the effectiveness and reproducibility of the described methods.

Effect of melatonin and nitric oxide on capacitation and apoptotic changes induced by epidermal growth factor in ram sperm

CONTEXT

Apart from the canonical cAMP-PKA pathway, ram sperm capacitation can be achieved by the MAPK ERK1/2 signalling cascade, activated by epidermal growth factor (EGF).

AIMS

This study aims to investigate the effect of melatonin and nitric oxide (NO·) on capacitation and apoptotic-like changes in EGF-capacitated ram spermatozoa.

METHODS

In vitro capacitation was induced by EGF in the absence or presence of melatonin (100pM or 1μM). Also, a NO· precursor, L-arginine, or a NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), were added to capacitation media to study the interaction of NO· and melatonin during EGF-capacitation. Sperm functionality parameters (motility, viability, capacitation state), apoptotic markers (caspase activation and DNA damage), NO· levels, and phosphorylated c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (assessed by Western blot), were evaluated in swim-up and capacitated samples with EGF.

KEY RESULTS

NO· levels and the apoptotic-related markers were raised after EGF incubation. Melatonin had a bimodal role on sperm EGF-capacitation, preventing it at high concentration and promoting acrosome reaction at low concentration, but neither of the two concentrations prevented the increase in apoptotic-like markers or NO· levels. However, melatonin at 1μM prevented the activation of JNK.

CONCLUSIONS

NO· metabolism does not seem to modulate the apoptosis-like events in ram spermatozoa. Melatonin at 1μM prevents ram sperm capacitation induced by EGF independently from nitric oxide metabolism, and it could be exerted by limiting the JNK mitogen-activated protein kinase (MAPK) activation.

IMPLICATIONS

This study improvesour understanding of the biochemical mechanisms involved in sperm capacitation, and ultimately, fertility.

Anti-PANoptosis is involved in neuroprotective effects of melatonin in acute ocular hypertension model

Acute ocular hypertension (AOH) is the most important characteristic of acute glaucoma, which can lead to retinal ganglion cell (RGC) death and permanent vision loss. So far, approved effective therapy is still lacking in acute glaucoma. PANoptosis (pyroptosis, apoptosis, and necroptosis), which consists of three key modes of programmed cell death-apoptosis, necroptosis, and pyroptosis-may contribute to AOH-induced RGC death. Previous studies have demonstrated that melatonin (N-acetyl-5-methoxytryptamine) exerts a neuroprotective effect in many retinal degenerative diseases. However, whether melatonin is anti-PANoptotic and neuroprotective in the progression of acute glaucoma remains unclear. Thus, this study aimed to explore the role of melatonin in AOH retinas and its underlying mechanisms. The results showed that melatonin treatment attenuated the loss of ganglion cell complex thickness, retinal nerve fiber layer thickness, and RGC after AOH injury, and improved the amplitudes of a-wave, b-wave, and oscillatory potentials in the electroretinogram. Additionally, the number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells was decreased, and the upregulation of cleaved caspase-8, cleaved caspase-3, Bax, and Bad and downregulation of Bcl-2 and p-Bad were inhibited after melatonin administration. Meanwhile, both the expression and activation of MLKL, RIP1, and RIP3, along with the number of PI-positive cells, were reduced in melatonin-treated mice, and p-RIP3 was in both RGC and microglia/macrophage after AOH injury. Furthermore, melatonin reduced the expression of NLRP3, ASC, cleaved caspase-1, gasdermin D (GSDMD), and cleaved GSDMD, and decreased the number of Iba1/interleukin-1β-positive cells. In conclusion, melatonin ameliorated retinal structure, prevented retinal dysfunction after AOH, and exerted a neuroprotective effect via inhibition of PANoptosis in AOH retinas.

A companion to the preclinical common data elements and case report forms for neuropathology studies in epilepsy research. A report of the TASK3 WG2 Neuropathology Working Group of the ILAE/AES Joint Translational Task Force

The International League Against Epilepsy/American Epilepsy Society (ILAE/AES) Joint Translational Task Force initiated the TASK3 working group to create common data elements (CDEs) for various aspects of preclinical epilepsy research studies, which could help improve the standardization of experimental designs. This article addresses neuropathological changes associated with seizures and epilepsy in rodent models of epilepsy. We discuss CDEs for histopathological parameters for neurodegeneration, changes in astrocyte morphology and function, mechanisms of inflammation, and changes in the blood-brain barrier and myelin/oligodendrocytes resulting from recurrent seizures in rats and mice. We provide detailed CDE tables and case report forms (CRFs), and with this companion manuscript, we discuss the rationale and methodological aspects of individual neuropathological examinations. The CDEs, CRFs, and companion paper are available to all researchers, and their use will benefit the harmonization and comparability of translational preclinical epilepsy research. The ultimate hope is to facilitate the development of rational therapy concepts for treating epilepsies, seizures, and comorbidities and the development of biomarkers assessing the pathological state of the disease.

N4 -allyldeoxycytidine: A New DNA Tag with Chemical Sequencing Power for Pinpointing Labelling Sites, Mapping Epigenetic Mark, and in situ Imaging

DNA tagging with base analogs has found numerous applications. To precisely record the DNA labelling information, it will be highly beneficial to develop chemical sequencing tags that can be encoded into DNA as regular bases and decoded as mutant bases upon a mild, efficient and bioorthognal chemical treatment. Here we reported such a DNA tag, N4-allyldeoxycytidine (a4dC), to label and identify DNA by in vitro assays. The iodination of a4dC led to fast and complete formation of 3, N4-cyclized deoxycytidine, which induced base misincorporation during DNA replication and thus could be located at single base resolution. We explored the applications of a4dC in pinpointing DNA labelling sites at single base resolution, mapping epigenetic mark N4-methyldeoxycytidine, and imaging nucleic acids in situ. In addition, mammalian cellular DNA could be metabolically labelled with a4dC. Together，our study sheds light on the design of next generation DNA tags with chemical sequencing power.

Influence of Non-conventional Sperm Quality Parameters on Field Fertility in Ovine

The prediction of the fertilizing ability of a seminal dose continues to be a primary aim in the field of artificial insemination (AI). To achieve this goal, in this study we have included the evaluation of some non-conventional sperm quality markers. A total of 3,906 ewes from 52 different farms were inseminated with 357 refrigerated seminal doses obtained from 45 mature Rasa Aragonesa rams. The same samples were used for sperm quality analysis including membrane integrity, capacitation status, oxygen consumption and apoptotic-like markers such as phosphatidylserine translocation (PS), plasmalemma disorganization/mitochondrial membrane potential, caspase activation and DNA damage. Seminal doses from the breeding (B) season presented higher percentages of intact membrane (IM), non permeant (NP) membrane with high mitochondrial membrane potential (ΔΨm) and IM without PS translocation spermatozoa than those from the non-breeding (NB) season. Therefore, we can conclude that there were less spermatozoa showing apoptotic-like features in the seminal doses from the B than the NB season, although these differences did not affect field fertility. Only the percentage of intact membrane, non-capacitated (IM-NC) spermatozoa showed a significant correlation with in vivo fertility (P = 0.005) and fecundity (P = 0.007) values obtained after cervical AI when all data were evaluated. When the data were sorted by season and distance to the farms where AI was performed, the correlation between the percentage of IM-NC spermatozoa and reproductive parameters increased in the NB season and progressively with remoteness from the farms. Some other sperm parameters, like NP with high ΔΨm, IM sperm without active caspases and DNA-intact spermatozoa, also showed significant correlations with the reproductive parameters in the sorted data. Moreover, the increment in both the percentage of IM-NC and DNA-intact spermatozoa would increase the probability of obtaining a fertility higher than the mean (>52%), as revealed by a multiple logistic regression analysis. In conclusion, we have identified two seminal markers—the percentage of intact membrane, non-capacitated spermatozoa, and DNA intact spermatozoa—which could be used as a test to discard males in AI programs, which is highly important from an economic point of view and can contribute to achieving satisfactory fertility rates.

Terahertz polarization sensing based on metasurface microsensor display anti-proliferation of tumor cells with aspirin

The inhibition effects of aspirin on cell proliferation are investigated by both traditional THz resonance sensing and the improved THz polarization sensing method based on a polarization dependent metasurface microsensor. Compared to resonance sensing, the quality factor of polarization sensing is 4∼5 times higher than that of resonance sensing, and its figure of merit is at least one order of magnitude higher than that of the resonance sensing with the same metasurface microsensor. Our proposed metasurface-based biosensors may supply a novel viewpoint on cell proliferation from a physical perspective and be a valuable complementary reference for biological study.

Disruption of galectin-3 and galectin-3 binding protein (G3BP) interaction by dietary pectic polysaccharides (DPP) - Arrest of metastasis, inhibition of proliferation and induction of apoptosis

Galectin-3 and galectin-3 binding proteins (G3BP) are implicated as key players in metastasis. In the current study, we evaluated the effect of pectic polysaccharides on galectin-3 and G3BP mediated metastasis in vitro (cells) and in vivo (tissues). In vitro study (double immunostaining) confirms the presence of galectin-3 on the cell surface and G3BP in the interlinking region of the cells confirming the role of G3BP in bridging galectin-3 molecules. Dietary carrot (Daucus carota) pectic polysaccharide (CRPP) blocked the expression of galectin-3 and G3BP more effectively (80%), whereas the expressions were reduced to 60% upon treatment with swallow root (Decalepis hamiltonii) pectic polysaccharide (SRPP), β‑carotene and deferoxamine (antiproliferative drug). Ginger (Gingiber officinale) pectic polysaccharide (GRPP) showed only 20% reduction. CRPP reduced 80% of tumor incidence followed by cyclophosphamide - a chemotherapeutic drug (77%), SRPP (67%) and GRPP (45%). Further 3-5 folds reduction in galectin-3/G3BP expression followed by infiltration of macrophages into the deeper layer of the skin by CRPP and SRPP suggested the anticancer property via immunomodulation. Surface Plasmon Resonance (SPR) studies confirm galectin-3 and G3BP interaction, which are disrupted during the treatment with dietary pectic polysaccharides (DPP) (Supplementary Scheme-1). Overall data demonstrate the role of DPPs as potential anticancer alternatives.

Ag(I) and Au(III) Mercaptobenzothiazole complexes induced apoptotic cell death

2-Mercaptobenzothiazole (MBT) complexes of Ag(I) and Au(III) were synthesized by wet chemical method. The structural, optical, 1HNMR, ICP - MS and electrochemical studies of the complexes were carried out. The TUNEL assay studies of Ag(I)MBT and Au(III)MBT complexes on A549 cell line indicated induced apoptosis in the cells. TUNEL assay showed 60% cell viability for Ag(I)MBT whereas 80% for Au(III)MBT. Thus Ag(I)MBT can induce cell apoptosis in cells at a higher rate than Au(III)MBT. Therefore these complexes studied here can be a viable option as anti - proliferating agent.

DNA Replication: From Radioisotopes to Click Chemistry

The replication of nuclear and mitochondrial DNA are basic processes assuring the doubling of the genetic information of eukaryotic cells. In research of the basic principles of DNA replication, and also in the studies focused on the cell cycle, an important role is played by artificially-prepared nucleoside and nucleotide analogues that serve as markers of newly synthesized DNA. These analogues are incorporated into the DNA during DNA replication, and are subsequently visualized. Several methods are used for their detection, including the highly popular click chemistry. This review aims to provide the readers with basic information about the various possibilities of the detection of replication activity using nucleoside and nucleotide analogues, and to show the strengths and weaknesses of those different detection systems, including click chemistry for microscopic studies.

Novel selenadiazole derivatives as selective antitumor and radical scavenging agents

Twenty-seven novel benzo[c][1,2,5]selenadiazole-5-carboxylic acid (BSCA) derivatives were designed and synthesized. Anti-proliferative activity of these structures was tested in vitro against a panel of five human cancer cell lines, including prostate (PC-3), colon (HT-29), leukemia (CCRF-CEM), lung (HTB-54) and breast (MCF-7). Four compounds (5, 6, 7 and 19) showed potent inhibitory activity with GI₅₀ values below 10 μM in at least one of the cancer cell lines. The selectivity of these compounds was further examined in two non-malignant cell lines derived from breast (184B5) and lung (BEAS-2B). Compound 7 exhibited promising anti-proliferative activity (GI₅₀ = 3.7 μM) in MCF-7 cells, together with high selectivity index (SI > 27.1). The induction of cell death by compound 7 was independent of the apoptotic process and it did not affect cell cycle progression either. Likewise, radical scavenging properties of the new selenadiazole derivatives were confirmed by testing their ability to scavenge DPPH radicals. Four compounds (1, 2, 8 and 9) showed potent radical scavenging activity, compound 9 being the most effective. Overall, while compound 7 was identified as the most cell growth inhibitory agent and selectively toxic to cancer cells, compound 9 proved to be the most potent antioxidant among the selenadiazole derivatives synthesized. This series of compounds can serve as an excellent scaffold to achieve new and potent antioxidant compounds useful for several diseases, i.e. cancer, neurodegenerative, heart diseases and leishmaniasis, considering the high radical scavenging activity and low toxicity showed by most of the compounds.

c-Jun N-terminal kinase and p38 mitogen-activated protein kinase pathways link capacitation with apoptosis and seminal plasma proteins protect sperm by interfering with both routes†

The mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), and p38 MAP kinase (p38) signaling cascades are involved in triggering apoptosis in somatic cells. Given that spermatozoa are able to undergo apoptosis, we tested the hypothesis that these pathways might be functional in ram spermatozoa as two signal transduction mechanisms that contribute to the modulation of capacitation and apoptosis. Indirect immunofluorescence and western blot analysis evidenced the presence of JNK and p38 in ram spermatozoa. To verify the involvement of these enzymes in sperm physiology, we determined the effect of specific inhibitors of JNK or p38 on in vitro capacitation induced with either cAMP-elevating agents or epidermal growth factor (EGF). Both inhibitions reduced the EGF-induced capacitation with a decrease in the chlortetracycline capacitated-sperm pattern, protein tyrosine phosphorylation, phosphatidylserine externalization, caspase-3 and -7 activation, and the proportion of DNA-damaged spermatozoa. No significant changes were found in the high-cAMP capacitated samples. The addition of 3.4 mg/ml seminal plasma proteins (SPPs) to the EGF-containing samples, either alone or together with each inhibitor, resulted in a decreased proportion of capacitated sperm pattern, protein tyrosine phosphorylation, loss of plasma membrane integrity, and apoptotic alterations. Furthermore, SPPs significantly reduced the phosphorylation level of JNK and p38 MAPK (active forms). These findings show a relationship between capacitation and apoptosis, and represent a step forward in the knowledge of the SPP protective mechanism in spermatozoa.

Biological function and mechanism of MALAT-1 in renal cell carcinoma proliferation and apoptosis: role of the MALAT-1-Livin protein interaction

Long noncoding RNAs (lncRNAs) have been shown to play a critical role in cancer development and progression. LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) is a kidney cancer-associated onco-lncRNA involved in the progression of renal cell carcinoma (RCC). However, the pathological role of lncRNA MALAT-1 in RCC proliferation and metastasis remains poorly understood. This study was designed to investigate the biological role and mechanism of MALAT-1 in RCC proliferation and metastasis. The experiments were performed in human tissues, renal carcinoma cell lines, and nude mice. The expression of lncRNA MALAT-1, Livin mRNA, and the Livin protein was determined by quantitative real-time PCR (qRT-PCR) or a Western blot. The interaction between MALAT-1 and Livin was evaluated by RNA pull-down and RNA binding protein immunoprecipitation (RIP). Cell viability and apoptosis in RCC cell lines were detected using CCK-8 and TUNEL assays. LncRNA MALAT-1 and the Livin protein were highly expressed in RCC tissues, as well as in RCC 786-O and Caki-1 cell lines. MALAT-1 interference contributed to an increase in cell apoptosis and a reduction in the cell viability of 786-O and Caki-1 cells. The increase in apoptosis by si-MALAT-1 was reversed by overexpression of Livin. The RIP results showed that MALAT-1 promoted the expression of the Livin protein in 786-O and Caki-1 cells by enhancing the stability of the protein. Furthermore, the volume of si-MALAT-1-786-O cell xenograft was significantly suppressed. These data indicate that lncRNA MALAT-1-mediated promotion of RCC proliferation and metastasis may be due to the upregulation of the expression of Livin.

TUNEL labeling with BrdUTP/anti-BrdUTP greatly underestimates the level of sperm DNA fragmentation in semen evaluation

Many studies have now confirmed that sperm DNA fragmentation (SDF) is associated with a poorer outcome of some forms of assisted reproduction technology. For this reason, SDF is an important parameter to evaluate in male fertility assessment. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay coupled to flow cytometry is one of the most promising methods for SDF quantification. Several kits for the detection of DNA fragmentation are currently available on the market and all are recommended as equally appropriate to quantify SDF. In this work we compared for the first time the efficacy of two different types of TUNEL kits for SDF quantification: one using an indirect antibody-based labeling system (BrdUTP/fluorescein-anti-BrdUTP) and another using a direct labeling system (fluorescein-dUTP). We demonstrated that TUNEL indirect labeling system largely underestimates SDF when compared with the direct labeling, the differences ranging from 19.2% to 85.3% (p<0.05, n = 22). We observed that these differences were most pronounced among dead spermatozoa where indirect labeling stained 40.1% [23.6%, 58.2%] and the direct system 65.7% [36.5%, 90.9%] (n = 10, p<0.05). Interestingly, we found that both systems stained the living spermatozoa with the same efficiency. We showed that the differences are due to the steric hindrance of the antibody during its binding to the BrdUTP. Indeed, after sperm DNA decondensation, the percentages of TUNEL positivity increased significantly from 46.3% [31.8%, 61.7%] to 97.5% [96.1%, 98.8%] (p<0.05, n = 5). Our results are important for future use of TUNEL in clinical practice. Laboratories relying on the use of an antibody-based system heavily underestimate SDF, most particularly in infertile patients with reduced sperm motility. As a consequence, the kit using BrdUTP/fluorescein-anti-BrdUTP should not be recommended as a method to assay DNA damage in semen. This study represents one further step in the standardization of TUNEL among laboratories.

The patch assay reconstitutes mature hair follicles by culture-expanded human cells

AIM

We tested whether the a simple injection known as the patch assay could reconstitute mature hair follicles by culture-expanded human cells and explored whether the assay could reflect the trichogenicity of cultured cells.

MATERIALS & METHODS

Dissociated culture-expanded fetal or adult scalp dermal cells combined with foreskin keratinocytes were subcutaneously injected into the back skin of immunosuppressive mice to form the patch skin. The patches were collected and characterized and were analyzed for hair formation efficiency.

RESULTS

Using culture-expanded human fetal cells, the patch assay can efficiently reconstitute mature hair follicles and the efficiency of hair formation in the patch assay correlates with cell trichogenicity.

CONCLUSION

The patch assay has the potential for testing the trichogenicity of human cells.

Cell cycle profiling by image and flow cytometry: The optimised protocol for the detection of replicational activity using 5-Bromo-2'-deoxyuridine, low concentration of hydrochloric acid and exonuclease III

The approach for the detection of replicational activity in cells using 5-bromo-2'-deoxyuridine, a low concentration of hydrochloric acid and exonuclease III is presented in the study. The described method was optimised with the aim to provide a fast and robust tool for the detection of DNA synthesis with minimal impact on the cellular structures using image and flow cytometry. The approach is based on the introduction of breaks into the DNA by the low concentration of hydrochloric acid followed by the subsequent enzymatic extension of these breaks using exonuclease III. Our data showed that the method has only a minimal effect on the tested protein localisations and is applicable both for formaldehyde- and ethanol-fixed cells. The approach partially also preserves the fluorescence of the fluorescent proteins in the HeLa cells expressing Fluorescent Ubiquitin Cell Cycle Indicator. In the case of the short labelling pulses that disabled the use of 5-ethynyl-2'-deoxyuridine because of the low specific signal, the described method provided a bright signal enabling reliable recognition of replicating cells. The optimized protocol was also successfully tested for the detection of trifluridine, the nucleoside used as an antiviral drug and in combination with tipiracil also for the treatment of some types of cancer.

Rapid Detection of DNA Strand Breaks in Apoptotic Cells by Flow- and Image-Cytometry

Extensive DNA fragmentation that generates a multitude of DNA double-stand breaks (DSBs) is a hallmark of apoptosis. We developed several variants of the widely used TUNEL methodology that is based on the use of exogenous terminal deoxynucleotidyl transferase (TdT) to label 3'OH ends in DSBs with fluorochromes. Flow- or image-cytometry is then employed to detect and quantify apoptotic cells labeled this way. Here, we describe a variant of this technique using BrdUTP as a TdT substrate. The incorporated BrdU is subsequently visualized by a fluorochrome-tagged antibody. This is a particularly simple, rapid, and sensitive approach to detect DSBs.We also describe modifications of the labeling protocol permitting the use of deoxyribonucleotides other than BrdUTP to label DSBs. Concurrent differential staining of cellular DNA and multiparameter analysis of cells by flow- or image-cytometry enable correlations between apoptosis induction and the cell cycle phase. Examples of the detection of apoptotic cells in cultures of human leukemic cell lines treated with TNF-α and DNA topoisomerase I inhibitor topotecan are presented. The protocol can be applied to cells treated with cytotoxic drugs in vitro, ex vivo, or to clinical samples.

Silencing of SRA1 Regulates ER Expression and Attenuates the Growth of Stromal Cells in Ovarian Endometriosis

Estradiol and its nuclear receptors, estrogen receptor (ER) α and ER-β, have important functions in endometriosis, and the transcriptional activity of these receptors is modulated by coactivators and corepressors. The steroid receptor RNA activator 1 (SRA1) produces SRA long noncoding RNA (lncRNA) and SRA protein (SRAP), which regulate ER expression at the RNA and protein levels in some hormone-dependent tumors via an alternative splicing event. However, only a few are reported on their expressions in endometriosis. Here, we observed that low expression levels of SRA lncRNA and ER-α but relatively high expression levels of SRAP and ER-β were detected in ovarian endometriotic tissues versus normal endometrial tissues. Steroid receptor RNA activator 1-small interfering RNA treatment significantly increased ER-α levels but reduced ER-β levels in endometriotic stromal cells (ESCs). Furthermore, the treatment can also attenuate the proliferation and promote early apoptosis in these cells. Our results indicate that the regulation of ER via SRA in ovarian endometriosis may play a significant role in the growth of ESCs.

The characterization of hematopoietic tissue in adult Chinese mitten crab Eriocheir sinensis

Invertebrates rely on the efficient innate immune mechanisms against invaders, in which the continuous production of hemocytes (hematopoiesis) is indispensable. In the present study, the hematopoietic tissue (HPT) from Chinese mitten crab Eriocheir sinensis was identified and characterized. It was a thin and non-transparent sheet located at the dorsolateral side of the stomach, which was composed of a series of ovoid lobules. Each lobule was surrounded by connective tissue containing a large amount of spherical cells with big nucleus. In HPT, the cells were full of mitochondria and granules, and DNA replication was detected in some cells by EdU labeling technique. Cell proliferation was observed in HPT by transmission electron microscope (TEM). The distribution of two transcription factors, GATA1 and RUNX1, were examined by human GATA1 and RUNX1 antibodies, respectively. Three homologues of RUNX1 were detected in the HPT while no signal of RUNX1 was observed in hemocytes, and GATA1 was detected in both HPT and some hemocytes. The mRNA transcript of a novel hematopoiesis related cytokine EsAst was detected in hepatopancreas and hemocytes, but it was no detectable in HPT. The mRNA expression level of EsAst in hepatopancreas was 1.38-fold higher than that in hemocytes. Total hemocytes counts were related to the mRNA expression level of EsAst post Aeromonas hydrophila challenge. The results suggested that the stem cells in the hematopoietic tissue of Chinese mitten crab E. sinensis were regulated by transcriptional and humoral factors to generate hemocytes.

Secondhand smoke induces hepatic apoptosis and fibrosis in hamster fetus

Secondhand smoke (SHS) is an important health issue worldwide. Inhaling SHS during pregnancy could cause abnormalities in the internal tissues of newborns, which may then impair fetal development and even cause severe intrauterine damage and perinatal death. However, the understanding of cytopathic mechanisms of SHS by maternal passive smoking on fetus liver during pregnancy is still limited. This study analyzed the effects of high-dose SHS (SHSH) on fetus liver using a maternal passive smoking animal model. Experiments showed that hepatic matrix metalloproteinase-9 activity and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling-positive cells were significantly increased in livers from fetuses of hamsters treated with SHSH. Similarly, expressions of both extrinsic and intrinsic apoptotic molecules were significantly higher in livers from fetuses of hamsters exposed to SHSH. Additionally, significantly increased inflammatory proteins, including transforming growth factor β, inducible nitric oxide synthase, and interleukin 1β, and fibrotic signaling molecules, including phosphorylated Smad2/3, SP1, and α-smooth muscle actin, were observed in the fetus livers from hamsters treated with SHSH. This study revealed that SHSH not only increased apoptosis through intrinsic and extrinsic pathways in the livers of fetuses from hamsters exposed to SHSH but also augmented hepatic fibrosis via Smad2/3 signaling.

Diverse profiles of ricin-cell interactions in the lung following intranasal exposure to ricin

Ricin, a plant-derived exotoxin, inhibits protein synthesis by ribosomal inactivation. Due to its wide availability and ease of preparation, ricin is considered a biothreat, foremost by respiratory exposure. We examined the in vivo interactions between ricin and cells of the lungs in mice intranasally exposed to the toxin and revealed multi-phasic cell-type-dependent binding profiles. While macrophages (MΦs) and dendritic cells (DCs) displayed biphasic binding to ricin, monophasic binding patterns were observed for other cell types; epithelial cells displayed early binding, while B cells and endothelial cells bound toxin late after intoxication. Neutrophils, which were massively recruited to the intoxicated lung, were refractive to toxin binding. Although epithelial cells bound ricin as early as MΦs and DCs, their rates of elimination differed considerably; a reduction in epithelial cell counts occurred late after intoxication and was restricted to alveolar type II cells only. The differential binding and cell-elimination patterns observed may stem from dissimilar accessibility of the toxin to different cells in the lung and may also reflect unequal interactions of the toxin with different cell-surface receptors. The multifaceted interactions observed in this study between ricin and the various cells of the target organ should be considered in the future development of efficient post-exposure countermeasures against ricin intoxication.

Inhibitory and apoptosis-inducing effects of Newcastle disease virus strain AF2240 on mammary carcinoma cell line

Breast cancer is the malignant tumour that developed from cells of the breast and is the first leading cause of cancer death among women worldwide. Surgery, radiotherapy, and chemotherapy are the available treatments for breast cancer, but these were reported to have side effects. Newcastle disease virus (NDV) known as Avian paramyxovirus type-1 (APMV1) belongs to the genus Avulavirus in a family Paramyxoviridae. NDV is shown to be a promising anticancer agent, killing tumour cells while sparing normal cells unharmed. In this study, the oncolytic and cytotoxic activities of NDV AF2240 strain were evaluated on MDA-MB-231, human mammary carcinoma cell line, using MTT assay, and its inhibitory effects were further studied using proliferation and migration assays. Morphological and apoptotic-inducing effects of NDV on MD-MB-231 cells were observed using phase contrast and fluorescence microscopes. Detection of DNA fragmentation was done following terminal deoxyribonucleotide transferase-mediated Br-dUTP nick end labeling staining (TUNEL) assay, which confirmed that the mode of death was through apoptosis and was quantified by flow cytometry. Furthermore, analysis of cellular DNA content demonstrated that the virus caused an increase in the sub-G1 phase (apoptotic peak) of the cell cycle. It appears that NDV AF2240 strain is a potent anticancer agent that induced apoptosis in time-dependent manner.

Titanium surfaces with nanostructures influence on osteoblasts proliferation: a systematic review

Objectives

Nanothechnology found to be increasingly implemented in implantology sphere over the recent years and it shows encouraging effect in this field. The aim of present review is to compare, based on the recent evidence, the influence of various nanostructure surface modifications of titanium for implants, on osteoblasts proliferation.

Material and Methods

A literature review of English articles was conducted by using MEDLINE database restricted to 2009 - 2014 and constructed according PRISMA guidelines. Search terms included “Titanium implant”, “Titanium surface with nanostructure”, “Osteoblast”. Additional studies were identified in bibliographies. Only in vitro and/or in vivo studies on nano structured implant surfaces plus control sample, with specific evaluation method for osteoblasts proliferation and at least one Ti sample with nanostructure, were included in the review.

Results

32 studies with 122 groups of examined samples were selected for present review. Each study conducted in vitro experiment, two studies conducted additional in vivo experiments. All studies were dispensed by type of surface modification into two major groups; “Direct ablative titanium implant surface nano-modifications” with 19 studies and ”Nanocomposite additive implant surface modifications” with 13 studies. Overall 24 studies reporting on positive effect of nanostructured surface, 2 studies found no significant advantage and 6 studies reported on negative effect compared to other structure scales.

Conclusions

From examination of selected articles we can notice marked advantage in implementation of various nanostructures onto implant surface. Yet for discovering the ultimate implant surface nanostructure, further comparable investigations of Ti surface nanostructures need to be done.

Delineating the anti-cytotoxic and anti-genotoxic potentials of catechin hydrate against cadmium toxicity in human peripheral blood lymphocytes

Catechins (flavan-3-ol) are a type of natural phenol and well-studied antioxidants. Catechin hydrate, also known as taxifolin; is non-mutagenic, low in toxicity compared to other immunomodulator antioxidants. We aimed to determine the potential of catechin hydrate to prevent the cyto-genotoxic effects of cadmium in lymphocytes; demonstrate the immuno-protective activity of catechin hydrate. Our previous study indicated that cadmium is apoptogenic. Lymphocytes were treated with catechin hydrate or cadmium and catechine hydrate combinations (range 0.1-100μM) to determine their effects on cell viability. Lymphocytes treated with 100μM catechin hydrate and 100μM cadmium showed cell viability 70.65±6.92% and 5.69±2.27%, respectively. In our previous study cadmium (10 and 20μM) induced apoptosis in 31.8% and 44.4% of lymphocytes, respectively. However, the percentage of apoptotic cells after treatment with the combination of cadmium and catechin hydrate was not significantly different from that of catechin hydrate (P>0.05). Only 7.3% and 10.5% of the lymphocytes were apoptotic after treatment with 10μM cadmium+10μM catechin hydrate and 20μM cadmium+20μM catechin hydrate, respectively. The anti-geno-cytotoxic and immuno-protective potential of catechin hydrate was also demonstrated by the non-significant expression of apoptosis-related genes after treatment with catechin hydrate.

Monitoring cell growth, viability, and apoptosis

The accurate determination of cell growth and viability is pivotal to monitoring a bioprocess. Direct methods to determine the cell growth and/or viability in a bioprocess include microscopic counting, electronic particle counting, image analysis, in situ biomass monitoring, and dieletrophoretic cytometry. These methods work most simply when a fixed volume sample can be taken from a suspension culture. Manual microscopic counting is laborious but affords the advantage of allowing cell viability to be determined if a suitable dye is included. Electronic particle counting is a rapid total cell count method for replicate samples, but some data distortion may occur if the sample has significant cell debris or cell aggregates. Image analysis based on the use of digital camera images acquired through a microscope has advanced rapidly with the availability of several commercially available software packages replacing manual microscopic counting and viability determination. Biomass probes detect cells by their dielectric properties or their internal concentration of NADH and can be used as a continuous monitor of the progress of a culture. While the monitoring of cell growth and viability is an integral part of a bioprocess, the monitoring of apoptosis induction is also becoming more and more important in bioprocess control to increase volumetric productivity by extending bioprocess duration. Different fluorescent assays allow for the detection of apoptotic characteristics in a cell sample.Indirect methods of cell determination involve the chemical analysis of a culture component or a measure of metabolic activity. These methods are most useful when it is difficult to obtain intact cell samples. However, the relationship between these parameters and the cell number may not be linear through the phases of a cell culture. The determination of nucleic acid (DNA) or total protein can be used as an estimate of biomass, while the depletion of glucose from the media can be used as an estimate of cellular activity. The state of cellular viability may be measured by the release of an enzyme such as lactate dehydrogenase or more directly from the intracellular adenylate energy charge from cell lysates. Alternatively, radioactive techniques may be used for an accurate determination of cellular protein synthesis.

The Rho-kinase inhibitor HA-1077 suppresses proliferation/migration and induces apoptosis of urothelial cancer cells

Background

Activation of Rho, one of the small GTPases, and its major downstream target Rho-kinase (ROCK) promotes the development and metastasis of cancer. We previously showed that elevation of Rho and ROCK expression was associated with tumor invasion, metastasis, and an unfavorable prognosis in patients with urothelial cancer of the bladder or upper urinary tract.

Methods

We investigated the effects of a ROCK inhibitor on the growth, migration, and apoptosis of bladder cancer cells. We also examined phosphorylation of RhoA (RhoA activity) by measuring its GTP-bound active form and assessed the expression of ROCK to explore the underlying molecular mechanisms.

Results

Lysophosphatidic acid (LPA) and geranylgeraniol (GGOH) induced an increase of cell proliferation and migration in association with promotion of RhoA activity and upregulation of ROCK expression. The ROCK inhibitor fasudil (HA-1077) suppressed cell proliferation and migration, and also induced apoptosis in a dose-dependent manner. HA-1077 dramatically suppressed the expression of ROCK-I and ROCK-II, but did not affect RhoA activity.

Conclusions

These findings suggest that ROCK could be a potential molecular target for the treatment of urothelial cancer.

The 140-kD isoform of CD56 (NCAM1) directs the molecular pathogenesis of ischemic cardiomyopathy

Despite recent advances in understanding the relevance of cell adhesion-related signaling in the pathogenesis of ischemic cardiomyopathy (ICM) in animal models, substantial questions remain unanswered in the human setting. We have previously shown that the neural cell adhesion molecule CD56 [neural cell adhesion molecule (NCAM1)] is specifically overexpressed in ICM; it was the aim of the current study to further elucidate the role of CD56 in the pathogenesis of human ICM. We used quantitative real-time PCR and IHC in human ICM and a rat model of coronary obstruction to demonstrate that CD56(140kD), the only extraneuronally expressed NCAM1 isoform with a cytoplasmic protein domain capable of inducing intracellular signaling, is the only up-regulated CD56 isoform in failing cardiomyocytes in human ICM in vivo. In subsequent analyses of the cellular effects of CD56(140kD) overexpression in the development of ICM using differential whole transcriptome expression analyses and functional in vitro cardiomyocyte cell culture assays, we further show that the up-regulation of CD56(140kD) is associated with profound gene expression changes, increased apoptosis, and reduced Ca(2+) signaling in failing human cardiomyocytes. Because apoptosis and Ca(2+)-related sarcomeric dysfunction are molecular hallmarks of ICM in humans, our results provide strong evidence that CD56(140kD) up-regulation plays a pivotal role in the pathogenesis of ICM and may be a target for future immunotherapeutic strategies in the treatment of this common and often fatal disease.

Baicalein (5,6,7-trihydroxyflavone) reduces oxidative stress-induced DNA damage by upregulating the DNA repair system

Oxidative stress caused by reactive oxygen species (ROS) induces DNA base modifications and DNA strand breaks. In this study, the protective effect of baicalein against H(2)O(2)-induced DNA damage was investigated in V79-4 Chinese hamster fibroblast cells. H(2)O(2) treatment increased the levels of intracellular ROS and DNA double-strand breaks (DSBs) and decreased the level of Ku70 protein and the phosphorylation (activation) of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), which are involved in the repair of DSBs by nonhomologous end joining. Baicalein effectively scavenged intracellular ROS induced by H(2)O(2), reduced DSBs, and rescued Ku70 protein level and phosphorylation of DNA-PKcs. In cellular response to DNA base damage, 8-oxoguanine DNA glycosylase 1 (OGG1) plays a vital role in the removal of 8-oxoguanine (8-OxoG), which is formed mainly by oxidative stress. Baicalein significantly decreased the levels of 8-OxoG induced by H(2)O(2), and this correlated with increases in OGG1 promoter activity and OGG1 mRNA and protein expression. The phosphorylated form of Akt kinase, which is a regulator of OGG1, was sharply decreased by H(2)O(2), but was prevented by baicalein. A specific Akt inhibitor abolished the cytoprotective effects of baicalein, suggesting that OGG1 induction by baicalein involves the Akt pathway. In conclusion, baicalein exerted protective effects against DNA damage induced by oxidative stress by activating DNA repair systems and scavenging ROS.

The effects of sodium diethyldithiocarbamate in fibroblasts V79 cells in relation to cytotoxicity, antioxidative enzymes, glutathione, and apoptosis

Sodium diethyldithiocarbamate (DETC) is the main metabolite of disulfiram. Recently, we reported that mechanism of disulfiram cytotoxicity in V79 cells might be partially connected with thiol redox-state imbalance. Here, we examined the effect of DETC on the level of intracellular glutathione (GSH), protein oxidation (measured as PC—protein carbonyl content), lipid peroxidation (measured as TBARS—thiobarbituric acid reactive substances), antioxidant enzymatic defense, as well as on apoptosis. We used V79 Chinese hamster fibroblasts cells with and without modulated glutathione (GSH) level by N-acetyl-l-cysteine (NAC). We showed that treatment with DETC at concentrations that cause a moderate increase in thiol-state imbalance but not cell death stimulates oxidative stress measured as increased level of PC and TBARS, adaptive response of GSH-related enzymes and apoptosis. Our results show that cellular effects of DETC are partially attributable to the initial redox cellular state, since the increase of GSH level by NAC pre-treatment prevented the observed changes.

Novel marine phenazines as potential cancer chemopreventive and anti-inflammatory agents

Two new (1 and 2) and one known phenazine derivative (lavanducyanin, 3) were isolated and identified from the fermentation broth of a marine-derived Streptomyces sp. (strain CNS284). In mammalian cell culture studies, compounds 1, 2 and 3 inhibited TNF-α-induced NFκB activity (IC₅₀ values of 4.1, 24.2, and 16.3 μM, respectively) and LPS-induced nitric oxide production (IC₅₀ values of >48.6, 15.1, and 8.0 μM, respectively). PGE₂ production was blocked with greater efficacy (IC₅₀ values of 7.5, 0.89, and 0.63 μM, respectively), possibly due to inhibition of cyclooxygenases in addition to the expression of COX-2. Treatment of cultured HL-60 cells led to dose-dependent accumulation in the subG1 compartment of the cell cycle, as a result of apoptosis. These data provide greater insight on the biological potential of phenazine derivatives, and some guidance on how various substituents may alter potential anti-inflammatory and anti-cancer effects.

Apoptosis and beyond: cytometry in studies of programmed cell death

A cell undergoing apoptosis demonstrates multitude of characteristic morphological and biochemical features, which vary depending on the inducer of apoptosis, cell type and the "time window" at which the process of apoptosis is observed. Because the gross majority of apoptotic hallmarks can be revealed by flow and image cytometry, the cytometric methods become a technology of choice in diverse studies of cellular demise. Variety of cytometric methods designed to identify apoptotic cells, detect particular events of apoptosis and probe mechanisms associated with this mode of cell death have been developed during the past two decades. In the present review, we outline commonly used methods that are based on the assessment of mitochondrial transmembrane potential, activation of caspases, DNA fragmentation, and plasma membrane alterations. We also present novel developments in the field such as the use of cyanine SYTO and TO-PRO family of probes. Strategies of selecting the optimal multiparameter approaches, as well as potential difficulties in the experimental procedures, are thoroughly summarized.

Detection of DNA strand breaks in apoptotic cells by flow- and image-cytometry

Extensive DNA fragmentation that generates a multitude of DNA double-strand breaks (DSBs) is a hallmark of apoptosis. A widely used approach to identify apoptotic cells relies on labeling DSBs in situ with fluorochromes. Flow or image cytometry is then used to detect and quantify apoptotic cells labeled this way. We developed several variants of the methodology that is based on the use of exogenous terminal deoxynucleotidyl transferase (TdT) to label 3'-OH ends of the DSBs with fluorochromes, defined as the TUNEL assay. This chapter describes the variant based on DSBs labeling using 5-Bromo-2'-deoxyuridine-5'-triphosphate (BrdUTP) as a TdT substrate and the incorporated BrdU is subsequently detected immunocytochemically with anti-BrdU antibody. We also describe modifications of the protocol that allow using other than BrdUTP deoxyribonucleotides to label DSBs. Concurrent differential staining of cellular DNA and multiparameter analysis of cells by flow- or image cytometry enables one to correlate the induction of apoptosis with the cell cycle phase. Examples of the detection of apoptotic cells in cultures of human leukemic cell lines treated with TNF-α and DNA topoisomerase I inhibitor topotecan are presented. The protocol can be applied to the cells growing in vitro, treated ex vivo with cytotoxic drugs as well as to clinical samples.

Introduction A: recent advances in cytometry instrumentation, probes, and methods--review

Cytometric techniques are continually being improved, refined, and adapted to new applications. This chapter briefly outlines recent advances in the field of cytometry with the main focus on new instrumentations in flow and image cytometry as well as new probes suitable for multiparametric analyses. There is a remarkable trend for miniaturizing cytometers, developing label-free and fluorescence-free analytical approaches, and designing "intelligent" probes. Furthermore, new methods for analyzing complex data for extracting relevant information are reviewed.

Induction of cytopathic effects and apoptosis in Spodoptera frugiperda cells by the HIV-1 Env glycoprotein signal peptide

The loss of CD4(+) T-cells in human immunodeficiency virus-infected individuals has been attributed not only to dysregulation of immune cell function but also direct and indirect killing mechanisms of both infected and bystander cells. This process proceeds through both necrotic and programmed cell death pathways. Several human immunodeficiency virus type 1 (HIV-1) gene products have been linked to the induction of cell death and apoptosis associated with virus infection. These include the Nef, Tat, Vpr, and Vpu proteins as well as the viral envelope glycoprotein. Our results now indicate that the signal peptide of HIV-1 is also involved in the induction of cytopathic effects leading to cell death. We have shown here that expression of HIV-1 gp120 or vesicular stomatitis virus G glycoprotein with the HIV-1 Env signal peptide resulted in a rapid induction of cytopathicity and cell death in S. frugiperda cells, whereas removal or replacement of the signal peptide ameliorated those effects. Further, our results show that cell death is induced, at least in part, through apoptotic pathways as characterized by evidence of nuclear condensation and DNA fragmentation, as well as by the activation of host-cell caspase activity. Our results indicate that the signal peptide of HIV-1 Env itself thus has a direct role in cellular cytotoxicity and the triggering of cell death pathways.

A Novel High-Throughput Technique for Identifying Monoclonal Antibodies Capable of Death Receptor Induced Apoptosis

The study of death receptor family induced apoptosis has gained momentum in recent years with the knowledge that therapeutic antibodies targeting DR4 and DR5 (death receptor's 4 and 5) have proved efficacious in multiple clinical trials. The therapeutic rationale is based on targeting and amplifying a tumour tissues normal cell death programme (apoptosis). While advances in the targeting of DR4 and DR5 have been successful the search for an agonistic antibody to another family member, the Fas receptor, has proven more elusive. This is partly due to the differing in vitro and in vivo characteristics of individual antibodies. In order to induce Fas targeted cell death an antibody must be capable of binding to and trimerising the receptor. It has been shown that antibodies capable of performing this function in vivo, with the assistance of tumour associated cells, do not always induce apoptosis in vitro. As a result the use of current methodologies to detect functional antibodies in vitro may have dismissed potential therapeutic candidates ('false negative'). Here we report a novel high throughput screening technique which artificially cross-links antibodies bound to the Fas receptor. By combining this process with Annexin-V and Prodidium Iodide (PI) staining we can select for antibodies which have the potential to induce apoptosis in vivo.

Cell death caused by single-stranded oligodeoxynucleotide-mediated targeted genomic sequence modification

Targeted gene repair directed by single-stranded oligodeoxynucleotides (ssODNs) offers a promising tool for biotechnology and gene therapy. However, the methodology is currently limited by its low frequency of repair events, variability, and low viability of "corrected" cells. In this study, we showed that during ssODN-mediated gene repair reaction, a significant population of corrected cells failed to divide, and were much more prone to undergo apoptosis, as marked by processing of caspases and PARP-1. In addition, we found that apoptotic cell death triggered by ssODN-mediated gene repair was largely independent of the ATM/ATR kinase. Furthermore, we examined the potential involvement of the mismatch repair (MMR) proteins in this "correction reaction-induced" cell death. Result showed that while defective MMR greatly enhanced the efficiency of gene correction, compromising the MMR system did not yield any viable corrected clone, indicating that the MMR machinery, although plays a critical role in determining ssODN-directed repair, was not involved in the observed cellular genotoxic responses.

Cytology of terminally differentiated Epulopiscium mother cells

Epulopiscium sp. type B, a member of the Firmicutes, is a large (up to 300 microm), cigar-shaped bacterial symbiont of surgeonfish that propagates itself by forming multiple intracellular offspring. This unusual form of reproduction is an apparent modification of a developmental program used by some Firmicutes to produce an endospore. At the onset of offspring formation, the Epulopiscium cell divides at both poles. The polar cells are engulfed by the larger mother cell and grow within the mother cell. At the final stages of development, the Epulopiscium mother cell lyses. Here we describe changes in Epulopiscium cell structure, focusing on mother cell DNA replication and cell death. DNA replication was examined by labeling cells with the nucleotide analog bromodeoxyuridine. As expected, DNA replication occurs in the developing offspring. However, well after passage of genetic information from parent to offspring is complete, DNA within the mother cell continues to replicate. Using fluorescence microscopy, we found that near the end of the offspring growth cycle, mother cell DNA disintegrates. The mother cell membrane and wall deteriorate as well. DNA replication within this terminally differentiated cell indicates the importance of mother cell nucleoids in cell maintenance and the development of offspring. The synchronized timing of mother cell deterioration within a population suggests that the Epulopiscium mother cell undergoes a programmed cell death. The programmed death of the mother cell may allow for the timely release of resources accumulated in the mother cell to provide nutrients to populations of these intestinal microbes and their host.

Analytical methods to assess nanoparticle toxicity

During the past 20 years, improvements in nanoscale materials synthesis and characterization have given scientists great control over the fabrication of materials with features between 1 and 100 nm, unlocking many unique size-dependent properties and, thus, promising many new and/or improved technologies. Recent years have found the integration of such materials into commercial goods; a current estimate suggests there are over 800 nanoparticle-containing consumer products (The Project on Emerging Nanotechnologies Consumer Products Inventory, , accessed Oct. 2008), accounting for 147 billion USD in products in 2007 (Nanomaterials state of the market Q3 2008: stealth success, broad impact, Lux Research Inc., New York, NY, 2008). Despite this increase in the prevalence of engineered nanomaterials, there is little known about their potential impacts on environmental health and safety. The field of nanotoxicology has formed in response to this lack of information and resulted in a flurry of research studies. Nanotoxicology relies on many analytical methods for the characterization of nanomaterials as well as their impacts on in vitro and in vivo function. This review provides a critical overview of these techniques from the perspective of an analytical chemist, and is intended to be used as a reference for scientists interested in conducting nanotoxicological research as well as those interested in nanotoxicological assay development.

Estrogen receptor (ER) beta regulates ERalpha expression in stromal cells derived from ovarian endometriosis

CONTEXT

Estradiol and its nuclear receptors, estrogen receptor (ER) alpha and ERbeta, play critical roles in endometrium and endometriosis. Levels of ERbeta, due to pathological hypomethylation of its promoter, are significantly higher in endometriotic vs. endometrial tissue and stromal cells, whereas ERalpha levels are lower in endometriosis. Estradiol regulates ERalpha gene expression via its alternatively used promoters A, B, and C.

OBJECTIVE

The aim of the study was to determine whether high levels of ERbeta in endometriotic stromal cells from ovarian endometriomas regulate ERalpha gene expression.

RESULTS

ERbeta knockdown significantly increased ERalpha mRNA and protein levels in endometriotic stromal cells. Conversely, ERbeta overexpression in endometrial stromal cells decreased ERalpha mRNA and protein levels. ERbeta knockdown significantly decreased proliferation of endometriotic stromal cells. Chromatin immunoprecipitation assays demonstrated that estradiol enhanced ERbeta binding to nonclassical activator protein 1 and specificity protein 1 motifs in the ERalpha gene promoters A and C and a classic estrogen response element in promoter B in endometriotic stromal cells.

CONCLUSIONS

High levels of ERbeta suppress ERalpha expression and response to estradiol in endometrial and endometriotic stromal cells via binding to classic and nonclassic DNA motifs in alternatively used ERalpha promoters. ERbeta also regulates cell cycle progression and might contribute to proliferation of endometriotic stromal cells. We speculate that a significantly increased ratio of ERbeta:ERalpha in endometriotic tissues may also suppress progesterone receptor expression and contribute to progesterone resistance. Thus, ERbeta may serve as a significant therapeutic target for endometriosis.

Analysis of DNA content and BrdU incorporation

During the past two decades, the techniques of analysis of cell cycle kinetics based upon the flow cytometric detection of BrdU incorporation have replaced the cumbersome autoradiographic methodology utilizing tritiated thymidine. This unit distills the knowledge gained over this time into concise and easy to follow protocols for DNA content analysis following thermal denaturation or acid denaturation, as well as a modified method that combines thermal denaturation with washless immunocytochemical detection of BrdU.

Analysis of DNA content and DNA strand breaks for detection of apoptotic cells

This unit describes a method for identifying apoptotic cells based on in situ detection of DNA strand breaks. Correlated analysis of DNA content and DNA strand breaks allows one not only to identify apoptotic cells but also to pinpoint their location in the cell cycle. The basic protocol uses 5-bromodeoxyuridine triphosphate to label the 3-OH termini of the breaks, but the procedure is easily adapted to a variety of other conjugates. Given the multiplicity of commercially available reagents it is possible to label DNA strand breaks with a dye of any fluorescence color and excitation wavelength.