Changes In Nuclear Morphology Research Articles

SiRNA - Mediated LRP/LR knock-down reduces cellular viability of malignant melanoma cells through the activation of apoptotic caspases

The 37 kDa/67 kDa laminin receptor (LRP/LR) is over-expressed in tumor cells and has been implicated in several tumourigenic processes such as metastasis and telomerase activation, however, more importantly the focus of the present study is on the maintenance of cellular viability and the evasion of apoptosis. The aim of the study was to investigate the role of LRP/LR on the cellular viability of early (A375) and late stage (A375SM) malignant melanoma cells. Flow cytometry and western blot analysis revealed that A375SM cells contain more cell-surface and total LRP/LR levels in comparison to the A375 cells, respectively. In order to determine the effect of LRP/LR on cell viability and apoptosis, LRP was down-regulated via siRNA technology. MTT assays revealed that LRP knock-down led to significant reductions in the viability of A375 and A375SM cells. Confocal microscopy indicated nuclear morphological changes suggestive of apoptotic induction in both cell lines and Annexin-V FITC/PI assays confirmed this observation. Additionally, caspase-3 activity assays revealed that apoptosis was induced in both cell lines after siRNA-mediated down-regulation of LRP. Caspase-8 and −9 activity assays suggested that post LRP knock-down; A375 cells undergo apoptosis solely via the extrinsic pathway, while A375SM cells undergo apoptosis via the intrinsic pathway.Implications: siRNAs mediated LRP knock-down might represent a powerful alternative therapeutic strategy for the treatment of malignant melanoma through the induction of apoptosis.

P38 inhibitor inhibits the apoptosis of cowanin-treated human colorectal adenocarcinoma cells.

Colorectal cancer, which is the third most common type of cancer diagnosed in both men and women, is the leading cause of cancer-related deaths worldwide. Cowanin is a pure compound extracted from Garciniacowa Roxb., a tree species present in Thailand, Malaysia and Myanmar. The crude extract has been demonstrated to have antitumor activity, inflammation induction, antibacterial activity, anti-inflammatory activity and antimalarial activity. In the present study, the effects of cowanin on apoptosis induction and on the apoptosis-related and mitogen-activated protein kinase (MAPK) pathways were investigated in the LoVo human colorectal cancer cell line. The cytotoxicity of cowanin in LoVo cells was determined by MTT assay. Hoechst33342 and JC‑1 staining were used to determine nuclear morphological changes and mitochondrial membrane potential, respectively. The expression levels of BCL2 apoptosis regulator (Bcl‑2) family, MAPK and AKT serine/threonine kinase1 (Akt) pathway proteins following cowanin treatment were determined by western blot analysis. The results demonstrated that cowanin inhibited cell proliferation and induced cell death via the apoptosis pathway. Cowanin treatment increased BCL2 associatedX (Bax) and decreased Bcl‑2 expression. In addition, cowanin activated caspase‑9, -7 and poly-ADP-ribose-polymerase expression. Furthermore, cowanin decreased the levels of phosphorylated extracellular signal-regulated kinase (p‑ERK), p‑Akt, p‑3‑phosphoinositide‑dependent protein kinase‑1, while it increased p‑p38 expression, thus resulting in the induction of apoptosis. In conclusion, cowanin inhibited cell proliferation and induced apoptosis of LoVo cells via the MAPK and Akt signaling pathways. Notably, inhibition of p38 by using a p38 inhibitor (SB203580) prevented the cowanin-induced apoptosis in LoVo cells. These results suggested that cowanin may be a potential candidate for the treatment of colorectal cancer and provided important information on the molecular mechanisms underlying its antitumor activity.

Sodium butyrate induces cell death by autophagy and reactivates a tumor suppressor gene DIRAS1 in renal cell carcinoma cell line UOK146.

Sodium butyrate (SB), a histone deacetylase inhibitor, is emerging as a potent anti-cancer drug for different types of cancers. In the present study, anti-cancer activity of SB in Xp11.2 (TFE3) translocated renal cell carcinoma cell line UOK146 was studied. Anti-proliferative effect of SB in renal cell carcinoma (RCC) cell line UOK146 was evaluated by MTT assay and morphological characteristics were observed by phase contrast microscopy which displayed the cell death after SB treatment. SB induces DNA fragmentation and change in nuclear morphology observed by increased sub-G1 region cell population and nuclear blebbings. Cell cycle arrest at G2/M phase was found after SB treatment. UOK146 cell line shows autophagy mode of cell death as displayed by acridine orange staining and flow cytometry analysis. LC3-II, a protein marker of autophagy, was also found to be upregulated after SB treatment. A tumor suppressor gene DIRAS1 was upregulated after SB treatment, displaying its anti-cancer potential at molecular level. These findings suggest that SB could serve as a novel regulator of tumor suppressors and lead to the discovery of novel therapeutics with better and enhanced anti-cancer activity.

Allicin induces apoptosis through activation of both intrinsic and extrinsic pathways in glioma cells.

Allicin is an extract purified from Alliumsativum (garlic), and previous research has indicated that Allicin has an inhibitory effect on many kinds of tumor cells. The aim of the present study was to explore the anticancer activity of Allicin on human glioma cells and investigate the underlying mechanism. MTT and colony-formation assays were performed to detect glioma cell proliferation, and explore the effect of Allicin at various doses and time-points. The apoptosis of glioma cells was measured by fluorescence microscopy with Hoechst33258 staining, and then flow cytometry was used to analyzed changes in glioma cell apoptosis. Reverse transcription‑quantitative polymerase chain reaction and western blot analysis were used to detect the effect of Allicin on the expression levels of Fas/Fas ligand (FasL), caspase‑3, B‑cell lymphoma2 and Bcl‑2‑associatedX protein. Allicin suppressed the proliferation and colony formation ability of U251cells in a dose‑and time‑dependent manner. A cytotoxic effect of Allicin was observed in glioma cells in a dose‑dependent manner. Changes in nuclear morphology were observed in U251 cells with Hoechst33258 staining. The activity of caspases were significantly elevated and Fas/FasL expression levels were increased following treatment with Allicin, at both the mRNA and protein level. These results demonstrated that Allicin suppresses proliferation and induces glioma cell apoptosis invitro. Both intrinsic mitochondrial and extrinsic Fas/FasL‑mediated pathways react in glioma cell after treating with Allicin, which then activate major apoptotic cascades. These results implicate Allicin as a novel antitumor agent in treating glioma.

Overexpression of the lamina proteins Lamin and Kugelkern induces specific ultrastructural alterations in the morphology of the nuclear envelope of intestinal stem cells and enterocytes

The nuclear envelope has a stereotypic morphology consisting of a flat double layer of the inner and outer nuclear membrane, with interspersed nuclear pores. Underlying and tightly linked to the inner nuclear membrane is the nuclear lamina, a proteinous layer of intermediate filament proteins and associated proteins. Physiological, experimental or pathological alterations in the constitution of the lamina lead to changes in nuclear morphology, such as blebs and lobulations. It has so far remained unclear whether the morphological changes depend on the differentiation state and the specific lamina protein. Here we analysed the ultrastructural morphology of the nuclear envelope in intestinal stem cells and differentiated enterocytes in adult Drosophila flies, in which the proteins Lam, Kugelkern or a farnesylated variant of LamC were overexpressed. Surprisingly, we detected distinct morphological features specific for the respective protein. Lam induced envelopes with multiple layers of membrane and lamina, surrounding the whole nucleus whereas farnesylated LamC induced the formation of a thick fibrillary lamina. In contrast, Kugelkern induced single-layered and double-layered intranuclear membrane structures, which are likely be derived from infoldings of the inner nuclear membrane or of the double layer of the envelope.

Assessment of sulforaphane-induced protective mechanisms against cadmium toxicity in human mesenchymal stem cells.

Cd is a hazardous substance and carcinogen that is present in the environment; it is known to cause toxic effects in living organisms. Sulforaphane is a naturally available phytochemical with antioxidant, anti-inflammatory, and anticarcinogenic properties. However, the effects of sulforaphane on Cd toxicity in human mesenchymal stem cells (hMSCs) are unknown. In the present study, we investigated the molecular mechanisms of the effects of sulforaphane on Cd toxicity in hMSCs by using MTT assays, acridine orange/ethidium bromide staining, Hoechst staining, LysoRed staining, assessment of mitochondrial membrane potential, and gene expression analysis. Cd decreased hMSC viability in a dose-dependent manner with an IC50 value of 56.5μM. However, sulforaphane did not induce any significant reduction in cell viability. Nuclear morphological analysis revealed that Cd induced necrotic cell death. Additionally, Cd caused mitochondrial membrane potential loss in hMSCs. The treatment of Cd-exposed cells with sulforaphane (Cd-sulforaphane co-treatment) resulted in a significant recovery of the cell viability and nuclear morphological changes compared with that of cells treated with Cd only. The gene expression pattern of cells co-treated with Cd-sulforaphane was markedly different from that of Cd-treated cells, owing to the reduction in Cd toxicity. Our results clearly indicated that sulforaphane reduced Cd-induced toxic effects in hMSCs. Overall, the results of our study suggested that sulforaphane-rich vegetables and fruits can help to improve human health through amelioration of the molecular effects of Cd poisoning.

A High-Throughput Real-Time Imaging Technique To Quantify NETosis and Distinguish Mechanisms of Cell Death in Human Neutrophils.

Neutrophils play a key role in host defenses and have recently been implicated in the pathogenesis of autoimmune diseases by various mechanisms, including formation of neutrophil extracellular traps through a recently described distinct form of programmed cell death called NETosis. Techniques to assess and quantitate NETosis in an unbiased, reproducible, and efficient way are lacking, considerably limiting the advancement of research in this field. We optimized and validated, a new method to automatically quantify the percentage of neutrophils undergoing NETosis in real time using the IncuCyte ZOOM imaging platform and the membrane-permeability properties of two DNA dyes. Neutrophils undergoing NETosis induced by various physiological stimuli showed distinct changes, with a loss of multilobulated nuclei, as well as nuclear decondensation followed by membrane compromise, and were accurately counted by applying filters based on fluorescence intensity and nuclear size. Findings were confirmed and validated with the established method of immunofluorescence microscopy. The platform was also validated to rapidly assess and quantify the dose-dependent effect of inhibitors of NETosis. In addition, this method was able to distinguish among neutrophils undergoing NETosis, apoptosis, or necrosis based on distinct changes in nuclear morphology and membrane integrity. The IncuCyte ZOOM platform is a novel real-time assay that quantifies NETosis in a rapid, automated, and reproducible way, significantly optimizing the study of neutrophils. This platform is a powerful tool to assess neutrophil physiology and NETosis, as well as to swiftly develop and test novel neutrophil targets.

Cytotoxic and apoptotic activity of nitrofuroxans on lymphoma cells

Five nitrofuroxans were synthesized and evaluated for their in vitro cytotoxicity against human lymphoma cells with different p53 status (Raji Burkitt's lymphoma and MOLT-4). The most promising compound exhibited IC50 values of 2.6–11.0 μM in MTT growth inhibitory assays. Flow cytometry data suggest that cytotoxic effects of given compounds in MOLT-4 cells are mediated by apoptosis via a p53-dependent pathway. Changes in nuclear morphology after treatment were evaluated by fluorescent microscopy after Hoechst staining. However, the studied nitrofuroxans did not induce apoptosis in Raji cells having the p53 mutant gene, thus suggesting a different mechanism of their action.

Identification of Malignancy-Associated Changes in Histologically Normal Tumor-Adjacent Epithelium of Patients with HPV-Positive Oropharyngeal Cancer

The incidence of HPV-positive oropharyngeal cancer (HPV+ OPC) is increasing, thus presenting new challenges for disease detection and management. Noninvasive methods involving brush biopsies of diseased tissues were recently reported as insufficient for tumor detection in HPV+ OPC patients, likely due to differences between the site of tumor initiation at the base of involuted crypts and the site of brush biopsy at the crypt surface. We hypothesized that histologically normal surface epithelial cells in the oropharynx contain changes in nuclear morphology that arise due to tumor proximity. We analyzed the nuclear phenotype of matched tumor, tumor-adjacent normal, and contralateral normal tissues from biopsies of nine HPV+ OPC patients. Measurements of 89 nuclear features were used to train a random forest-based classifier to discriminate between normal and tumor nuclei. We then extracted voting scores from the trained classifier, which classify nuclei on a continuous scale from zero (“normal-like”) to one (“tumor-like”). In each case, the average score of the adjacent normal nuclei was intermediate between the tumor and contralateral normal nuclei. These results provide evidence for the existence of phenotypic changes in histologically normal, tumor-adjacent surface epithelial cells, which could be used as brush biopsy-based biomarkers for HPV+ OPC detection.

Potential Synergism of Caffeic Acid Phenethyl Ester and Dasatinib in C6 Glioma Cell Model: Adumbrating the Molecular Mechanism

1.1 Background: Gliomas are one of the most invasive, highly recurrent, heterogeneous cancers resistant to most of the current treatment regimes and hence almost incurable. CAPE and Dasatinib when used in a congruous combination and durations, present an antitumor potential for glioma. 1.2 Objective: CAPE and Dasatinib in combination have been shown to inhibit proliferation and induce apoptosis in C6 glioma cells. However, the signaling pathway of their antiproliferative and apoptotic effects remains unknown. In this study, the antiproliferative effects of combination treatment on C6 glioma cells were investigated. 1.3 Methods: Expression analysis of proteins thought to be mediating proliferation, cell motility, angiogenesis, and invasion was carried out to delineate the molecular mechanism entailing antineoplastic action of CAPE and Dasatinib. 1.4 Results: Co-treatment induces a change in cellular and nuclear morphology followed by apoptosis and a significant decrease in the activity of catalase and MMP-2, Pro-MMP 2, MMP-9 and Pro-MMP 9 in C6 glioma cells. Moreover, CAPE and Dasatinib modulate the expression of proteins having potential interactive crosstalk with major oncogenic pathways involved in glioma progression. Our results showed that combination treatment modulates the expression of p53, ERK1/2, and AKT in C6 glioma cells. p53, EGFR and PCNA transcript expressions were attuned in co-treated C6 cells. 1.5 Conclusion: Importantly, antineoplastic effects of CAPE and Dasatinib were far greater than those afforded by treatment with a single drug. Together these drugs reduce glioma proliferation and invasion felicitously implying that combination treatment could be a useful therapy for treatment of glioma.

Volatile oil from alpinia officinarum promotes lung cancer regression in vitro and in vivo.

The anti-lung cancer activity of volatile oil from Alpinia officinarum (VOAO) and the underlying mechanism has not been studied. Herein, VOAO was extracted by steam distillation and its components were identified by GC-MS analysis. Cells viability was measured by an MTT assay and the cell survival capacity was tested via a colony formation assay. Apoptosis cells were detected using the Annexin V-FITC/PI method. Hoechst 33342 cell unclear staining was employed to evaluate the nuclear morphology change. The mitochondrial membrane potential was detected by a JC-1 staining assay. Bcl-2, Mcl-1 and cleaved caspase-3 proteins were quantified by immune blotting. Furthermore, VOAO anti-cancer activity was evaluated on an A549 cell xenograft nude mice model. Our results have revealed that VOAO could inhibit the cell viability of lung carcinoma cells and the colony formation capacity. VOAO downregulates Bcl-2 and Mcl-1 and triggers dysfunction of the mitochondrial membrane potential. VOAO further activates caspase-3 cleavage and induces lung cancer cells apoptosis. In addition, VOAO administration significantly suppresses lung cancer growth in xenograft mice without obvious hepatotoxicity. We conclude that VOAO could be an effective, low cytotoxicity natural component for treatment of lung carcinoma.

Identifications of cell state by grasping nuclear morphology change during cell cycle

Identifications of cell state by grasping nuclear morphology change during cell cycle

In vitro apoptotic mechanism of a novel synthetic Quinazolinyl derivative: Induces caspase-dependent intrinsic pathway on THP-1, leukemia cell line

Several quinazoline derivatives have been found to possess a broad spectrum of biological activities. Previously our research group has synthesized and studied the anti-proliferative effects of N-Decyl-N-(2-Methyl-4-Quinazolinyl) Amine (DMQA). The current study evaluated the cytotoxic and apoptotic properties of DMQA in THP-1 cells. The cytotoxic potential of DMQA was assessed using MTT assay on a panel of cancer cell lines which include HeLa, Mia PaCa-2, A 375, B16-F10, A 549,A 431, U937, THP-1, HL-60 and peripheral blood mononuclear cells (PBMC's). Preliminary data revealed that the highest cytotoxic activity was against THP-1 leukemia cell line (IC50=0.66 μg/ml). The apoptotic properties of DMQA on THP-1 cells were characterized by change in nuclear morphology, DNA fragmentation, reduction of pro-caspases-3, 9, Bax/Bcl-2 levels, cleavage of poly (ADP-ribose) polymerase and cytosolic release of cytochrome c. Further investigation revealed a sub-G1 peak, phosphatidyl serine exposure and loss of mitochondrial membrane potential (MMP) in THP-1 cells. The role of caspases was crucial and was demonstrated by the inhibitors Z-VAD-FMK and Z-DEVD-FMK. Moreover DMQA was markedly less effective in inhibiting the growth of normal cells (PBMC's, IC50 =62.17 μg/ml). Based on the results we suggest that DMQA induced apoptosis via intrinsic pathway and could be a promising anticancer agent.

Virus-induced apoptosis and phosphorylation form of metacaspase in the marine coccolithophorid Emiliania huxleyi.

Lytic viral infection and programmed cell death (PCD) are thought to represent two distinct death mechanisms in phytoplankton, unicellular photoautotrophs that drift with ocean currents. PCD (apoptosis) is mainly brought about by the activation of caspases, a protease family with unique substrate selectivity. Here, we demonstrated that virus infection induced apoptosis of marine coccolithophorid Emiliania huxleyi BOF92 involving activation of metacaspase. E. huxleyi cells exhibited cell death process akin to that of apoptosis when exposed to virus infection. We observed typical hallmarks of apoptosis including cell shrinkage, associated nuclear morphological changes and DNA fragmentation. Immunoblotting revealed that antibody against human active-caspase-3 shared epitopes with a protein of ≈ 23kDa; whose pattern of expression correlated with the onset of cell death. Moreover, analysis on two-dimensional gel electrophoresis revealed that two spots of active caspase-3 co-migrated with the different isoelectric points. Phosphatase treatment of cytosolic extracts containing active caspases-3 showed a mobility shift, suggesting that phosphorylated form of this enzyme might be present in the extracts. Computational prediction of phosphorylation sites based on the amino acid sequence of E. huxleyi metacaspase showed multiple phosphorylated sites for serine, threonine and tyrosine residues. This is the first report showing that phosphorylation modification of metacaspase in E. huxleyi might be required for certain biochemical and morphological changes during virus induced apoptosis.

Epigallocatechin-3-O-gallate alleviates the malignant phenotype in A-431 epidermoid and SK-BR-3 breast cancer cell lines

In this study, we evaluated the effects of epigallocatechin-3-O-gallate (EGCG) in two cancer cell lines, A-431 overexpressing ErbB1 and SK-BR-3, overexpressing ErbB2. EGCG treatment showed dose-dependent collapse of mitochondrial membrane potential (Δψm), increase in reactive oxygen species (ROS) production, changes in nuclear morphology and reduced viability. Flow cytometry data indicated that EGCG partially decreases the phosphorylation of several proteins involved in cell proliferation and survival: pErbB1(Y1173, Y1068), pAkt(S473) and pERK(Y204). EGCG affected the clonogenic growth in both cell lines with an EC50 of 2.5 and 5.4 µM for A-431 and SK-BR-3, respectively. Wound scratch assay demonstrated that EGCG inhibited the healing in dose-dependent manner and the effect was correlated with partial reduction in phosphorylation of pFAK(S910). Our data suggest that EGCG administration might reduce the unfavourable traits, particularly associated with ErbB1/EGFR overexpression.

Breaking the scale: how disrupting the karyoplasmic ratio gives cancer cells an advantage for metastatic invasion.

Nuclear size normally scales with the size of the cell, but in cancer this 'karyoplasmic ratio' is disrupted. This is particularly so in more metastatic tumors where changes in the karyoplasmic ratio are used in both diagnosis and prognosis for several tumor types. However, the direction of nuclear size changes differs for particular tumor types: for example in breast cancer, larger nuclear size correlates with increased metastasis, while for lung cancer smaller nuclear size correlates with increased metastasis. Thus, there must be tissue-specific drivers of the nuclear size changes, but proteins thus far linked to nuclear size regulation are widely expressed. Notably, for these tumor types, ploidy changes have been excluded as the basis for nuclear size changes, and so, the increased metastasis is more likely to have a basis in the nuclear morphology change itself. We review what is known about nuclear size regulation and postulate how such nuclear size changes can increase metastasis and why the directionality can differ for particular tumor types.

Low-level laser irradiation induces in vitro proliferation of stem cells from human exfoliated deciduous teeth.

The aim of this study was to evaluate the effect of low-level laser irradiation (LLLI) on the proliferation and viability of stem cells from human exfoliated deciduous teeth (SHED). Cells were irradiated or not (control) with an InGaAlP laser diode (660nm, 30mW, continuous action mode) using two different energy densities (0.5J/cm2-16s; 1.0J/cm2-33s). Irradiation was performed at 0 and 48h, with the laser probe fixed at a distance of 0.5cm from the cells. Cell proliferation was analyzed at 0, 24, 48, and 72h by the Trypan blue exclusion method and MTT assay. Cell cycle and Ki67 expression were analyzed by flow cytometry. Apoptosis-related events were evaluated by expression of annexin V/PI and nuclear morphological changes by staining with DAPI. Differences between groups at each time were analyzed by the Kruskal-Wallis and Mann-Whitney tests, adopting a level of significance of 5% (p<0.05). The results showed that an energy density of 1.0J/cm2 promoted an increase in cell proliferation at 48 and 72h compared to the control and 0.5J/cm2 groups. Cell cycle analysis revealed a predominance of cells in the S and G2/M phases in the irradiated groups. This finding was confirmed by the increased expression of Ki67. Low positive staining for annexin V and PI was observed in all groups, and no nuclear changes were detected, indicating that cell viability was not affected by the energy densities tested. It can be concluded that the LLLI parameters used (660nm, 30mW, 1.0J/cm2) promote the proliferation of SHEDs and the maintenance of cell viability.

Segmentation and classification of two-channel C. elegans nucleus-labeled fluorescence images

BackgroundAging is characterized by a gradual breakdown of cellular structures. Nuclear abnormality is a hallmark of progeria in human. Analysis of age-dependent nuclear morphological changes in Caenorhabditis elegans is of great value to aging research, and this calls for an automatic image processing method that is suitable for both normal and abnormal structures.ResultsOur image processing method consists of nuclear segmentation, feature extraction and classification. First, taking up the challenges of defining individual nuclei with fuzzy boundaries or in a clump, we developed an accurate nuclear segmentation method using fused two-channel images with seed-based cluster splitting and k-means algorithm, and achieved a high precision against the manual segmentation results. Next, we extracted three groups of nuclear features, among which five features were selected by minimum Redundancy Maximum Relevance (mRMR) for classifiers. After comparing the classification performances of several popular techniques, we identified that Random Forest, which achieved a mean class accuracy (MCA) of 98.69%, was the best classifier for our data set. Lastly, we demonstrated the method with two quantitative analyses of C. elegans nuclei, which led to the discovery of two possible longevity indicators.ConclusionsWe produced an automatic image processing method for two-channel C. elegans nucleus-labeled fluorescence images. It frees biologists from segmenting and classifying the nuclei manually.

Etlingera elatior Extract promotes cell death in B16 melanoma cells via down-regulation of ERK and Akt signaling pathways

BackgroundTorch ginger (Etlingera elatior, EE) is a ginger plant that found in Southeast Asia. Previous study showed its flowers and leaves composed of several flavonoids with anti-cancer activity. This study aims to investigate the mechanism of EE extract on cell death induction in melanoma cells.MethodsTo carry out this study, the cytotoxic effect of EE extract was performed using MTT assay. Nuclear morphological change and loss of mitochondrial membrane potential were observed using Hoechst 33,342 and JC-1 staining. Flow cytometry using Annexin V/PI double staining assessed apoptosis, necrosis and viability. Caspase activity was detected by caspase activity kits. The expression of Bcl-2 family proteins, ERK and Akt signaling pathways were examined by Western blot analysis.ResultsThe treatment of EE extract resulted in a dose- and time-dependent reduction in cell viability in B16 cells. It also induced nuclear condensation, phosphatidylserine exposure, and loss of mitochondrial membrane potential, which are markers of apoptosis. Furthermore, the expression of Bim was increased instead of Bax and Bcl-2. The results also showed caspase-independent activity and the down-regulation of ERK and Akt signaling pathway.ConclusionThe results suggest that EE extract induced caspase-independent cell death via down-regulation of ERK and Akt pathways in B16 cells. This may be beneficial as a chemopreventive or chemotherapeutic agent in melanoma treatment.

Autophagy plays a positive role in zinc-induced apoptosis in intestinal porcine epithelial cells

A high‑zinc (Zn) diet has been found to promote growth performance in pigs, but causes cell apoptosis in the intestinal epithelium. To investigate the mechanism underlying the high dietary Zn-induced apoptosis in porcine small intestinal epithelium, IPEC-J2 cells (intestinal porcine epithelial cells) were used to determine the effect of Zn on cell inhibitory, apoptosis, and mitochondrial membrane potential and autophagy in vitro. Results showed that Zn inhibited IPEC-J2 cell proliferation and induced apoptosis and autophagy. High concentrations of Zn induced DNA fragmentation and nuclear morphological changes, and increased intracellular Zn concentration. It also increased the protein expression level of cleaved caspase-3, caspase-8, beclin 1 and microtubule-associated protein 1 light chain 3 (LC3)-II, and the translocation of cytochrome c (Cyto C) into cytosol from mitochondria, and decreased the protein expression level of P62/SQSTM1. While 3-MA (3-methyladenine, as an autophagy inhibitor) suppressed the Zn-induced changes in the protein expression level of cleaved caspase-3 (CASP3), caspase-8 (CASP8), Cyto C, beclin 1, LC3-II and P62/SQSTM1. 3-MA decreased the Zn-induced mitochondrial apoptosis. High concentration of Zn up-regulated the relative mRNA expression level of BAX, CYCS, CASP3, CASP8, LC3-II and P62/SQSTM1 genes (p<0.05), which were also ameliorated by 3-MA supplementation. In conclusion, autophagy inhibition significantly reduced the Zn-induced loss of mitochondrial membrane potential and attenuated the elevation of apoptosis in IPEC-J2. Autophagy and apoptosis act as partners in the Zn-induced cellular death in IPEC-J2.